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    <title>DEV Community: Mikhail Panichev</title>
    <description>The latest articles on DEV Community by Mikhail Panichev (@denisinvader).</description>
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      <title>DEV Community: Mikhail Panichev</title>
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    <item>
      <title>How to Build a Home Cloud with Proxmox</title>
      <dc:creator>Mikhail Panichev</dc:creator>
      <pubDate>Fri, 27 Feb 2026 23:07:30 +0000</pubDate>
      <link>https://dev.to/denisinvader/how-to-build-a-home-cloud-with-proxmox-1n9m</link>
      <guid>https://dev.to/denisinvader/how-to-build-a-home-cloud-with-proxmox-1n9m</guid>
      <description>&lt;p&gt;One day, I realized I wanted a home server to experiment with deployment and infrastructure. Posts on &lt;a href="https://www.reddit.com/r/homelab/" rel="noopener noreferrer"&gt;r/homelab&lt;/a&gt; and &lt;a href="https://www.reddit.com/r/selfhosted/" rel="noopener noreferrer"&gt;r/selfhosted&lt;/a&gt; largely inspired this idea.&lt;/p&gt;

&lt;p&gt;At first, I considered going the bare-metal route and building a k3s cluster on several Raspberry Pis. However, after comparing costs, limitations, and capabilities, I decided to buy a couple of Lenovo ThinkCentre mini PCs and install &lt;a href="https://www.proxmox.com/" rel="noopener noreferrer"&gt;Proxmox Virtual Environment (PVE)&lt;/a&gt; on them.&lt;/p&gt;

&lt;p&gt;At work I’ve actively used cloud providers, so it was important for me to have a user-friendly experience with virtual servers — similar to what a compute cloud offers.&lt;/p&gt;

&lt;p&gt;Key requirements for the virtualization infrastructure:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;VMs may be on an isolated network, inaccessible from the home network;&lt;/li&gt;
&lt;li&gt;easy creation of a Debian server with cloud-init;&lt;/li&gt;
&lt;li&gt;server management via Terraform.&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;After spending several days searching online, tweaking configs, and reinstalling everything from scratch a couple of times, I came up with a working solution and identified some pitfalls.&lt;/p&gt;

&lt;h2&gt;
  
  
  Preparing a Private Network
&lt;/h2&gt;

&lt;p&gt;I decided to ensure basic security by placing virtual servers on a network separate from other devices.&lt;/p&gt;

&lt;p&gt;Instead of spending time on VLANs, complex routing, and firewalls, I used a separate Linux Bridge on the PVE host.&lt;/p&gt;

&lt;p&gt;The diagram below shows the conceptual network layout. All VMs connect to the private network interface &lt;code&gt;vmbr1&lt;/code&gt;. VMs that need to be accessible from the home network also connect to the &lt;code&gt;vmbr0&lt;/code&gt; interface.&lt;br&gt;
To provide internet access to private VMs, NAT is implemented from &lt;code&gt;vmbr1&lt;/code&gt; through &lt;code&gt;vmbr0&lt;/code&gt;.&lt;/p&gt;

&lt;p&gt;&lt;a href="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Farticles%2F4xl87y1cfuetpu94ic4u.png" class="article-body-image-wrapper"&gt;&lt;img src="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Farticles%2F4xl87y1cfuetpu94ic4u.png" alt="A schematic diagram showing virtual machines on the PVE private network 10.x.x.x, with one of them accessible on the home network 192.168.1.x" width="800" height="601"&gt;&lt;/a&gt;&lt;/p&gt;

&lt;p&gt;You can add the private network interface through the Proxmox admin or using &lt;a href="https://wiki.debian.org/NetworkConfiguration" rel="noopener noreferrer"&gt;default Debian tooling&lt;/a&gt;.&lt;/p&gt;

&lt;p&gt;Let’s go with the second option and add the following configuration to the &lt;code&gt;/etc/network/interfaces&lt;/code&gt; file:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;auto vmbr1
iface vmbr1 inet static
    address 10.0.2.1/24
    bridge-ports none
    bridge-stp off
    bridge-fd 0
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Activate the new interface with this command:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight shell"&gt;&lt;code&gt;ifup vmbr1
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The newly created interface should appear in the Proxmox control panel.&lt;/p&gt;

&lt;p&gt;&lt;a href="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Farticles%2Fvdj4skls5n169m06ukox.png" class="article-body-image-wrapper"&gt;&lt;img src="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Farticles%2Fvdj4skls5n169m06ukox.png" alt="Screenshot of network settings from the Proxmox control panel after adding a new interface" width="800" height="240"&gt;&lt;/a&gt;&lt;/p&gt;

&lt;p&gt;To give VMs internet access, you need to set up NAT.&lt;/p&gt;

&lt;p&gt;In the &lt;code&gt;/etc/sysctl.conf&lt;/code&gt; file, enable IP forwarding by adding this line:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;net.ipv4.ip_forward=1
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Apply this setting right away with the following command:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight shell"&gt;&lt;code&gt;sysctl &lt;span class="nt"&gt;-w&lt;/span&gt; net.ipv4.ip_forward&lt;span class="o"&gt;=&lt;/span&gt;1
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Next, enable NAT in &lt;code&gt;iptables&lt;/code&gt; with this command:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight shell"&gt;&lt;code&gt;iptables &lt;span class="nt"&gt;-t&lt;/span&gt; nat &lt;span class="nt"&gt;-A&lt;/span&gt; POSTROUTING &lt;span class="nt"&gt;-s&lt;/span&gt; 10.0.2.0/24 &lt;span class="nt"&gt;-o&lt;/span&gt; vmbr0 &lt;span class="nt"&gt;-j&lt;/span&gt; MASQUERADE
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Here, &lt;code&gt;vmbr0&lt;/code&gt; is the name of the interface with internet access.&lt;/p&gt;

&lt;p&gt;To preserve &lt;code&gt;iptables&lt;/code&gt; settings across reboots, install the &lt;code&gt;iptables-persistent&lt;/code&gt; package:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight shell"&gt;&lt;code&gt;apt &lt;span class="nb"&gt;install &lt;/span&gt;iptables-persistent
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The network is now configured, and we can move on to the next step.&lt;/p&gt;

&lt;h2&gt;
  
  
  Preparing the Image
&lt;/h2&gt;

&lt;p&gt;To create VMs similar to those in the cloud, you need a special &lt;a href="https://cdimage.debian.org/images/cloud/" rel="noopener noreferrer"&gt;Debian cloud image&lt;/a&gt;.&lt;/p&gt;

&lt;p&gt;You’ll also need tools to modify virtual machine images:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight shell"&gt;&lt;code&gt;apt &lt;span class="nb"&gt;install &lt;/span&gt;libguestfs-tools
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Here’s the command to download and prepare the image for use as a template:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight shell"&gt;&lt;code&gt;wget https://cloud.debian.org/images/cloud/bookworm/latest/debian-12-generic-amd64.qcow2 &lt;span class="se"&gt;\&lt;/span&gt;
&lt;span class="o"&gt;&amp;amp;&amp;amp;&lt;/span&gt; virt-customize &lt;span class="nt"&gt;-a&lt;/span&gt; debian-12-generic-amd64.qcow2 &lt;span class="nt"&gt;--install&lt;/span&gt; qemu-guest-agent,net-tools &lt;span class="se"&gt;\&lt;/span&gt;
&lt;span class="o"&gt;&amp;amp;&amp;amp;&lt;/span&gt; virt-customize &lt;span class="nt"&gt;-a&lt;/span&gt; debian-12-generic-amd64.qcow2 &lt;span class="nt"&gt;--run-command&lt;/span&gt; &lt;span class="s2"&gt;"echo 'en_US.UTF-8 UTF-8' &amp;gt;&amp;gt; /etc/locale.gen"&lt;/span&gt; &lt;span class="se"&gt;\&lt;/span&gt;
&lt;span class="o"&gt;&amp;amp;&amp;amp;&lt;/span&gt; virt-customize &lt;span class="nt"&gt;-a&lt;/span&gt; debian-12-generic-amd64.qcow2 &lt;span class="nt"&gt;--run-command&lt;/span&gt; &lt;span class="s2"&gt;"locale-gen"&lt;/span&gt; &lt;span class="se"&gt;\&lt;/span&gt;
&lt;span class="o"&gt;&amp;amp;&amp;amp;&lt;/span&gt; virt-customize &lt;span class="nt"&gt;-a&lt;/span&gt; debian-12-generic-amd64.qcow2 &lt;span class="nt"&gt;--run-command&lt;/span&gt; &lt;span class="s2"&gt;"update-locale LANGUAGE=en_US.UTF-8 LC_ALL=en_US.UTF-8 LC_CTYPE=en_US.UTF-8 LANG=en_US.UTF-8"&lt;/span&gt; &lt;span class="se"&gt;\&lt;/span&gt;
&lt;span class="o"&gt;&amp;amp;&amp;amp;&lt;/span&gt; virt-customize &lt;span class="nt"&gt;-a&lt;/span&gt; debian-12-generic-amd64.qcow2 &lt;span class="nt"&gt;--truncate&lt;/span&gt; /etc/machine-id
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;In the &lt;code&gt;--install&lt;/code&gt; argument, you can specify additional packages that will be automatically installed every time. The &lt;code&gt;qemu-guest-agent&lt;/code&gt; package is required for the PVE agent to work.&lt;/p&gt;

&lt;p&gt;It’s also important to run &lt;code&gt;--truncate /etc/machine-id&lt;/code&gt; so that a unique identifier is generated for each copied VM.&lt;/p&gt;

&lt;p&gt;Locale manipulations aren’t mandatory, but they help avoid pesky locale error messages when working via SSH.&lt;/p&gt;

&lt;p&gt;Once the image is prepared, you need to create the actual VM template in Proxmox. You can do this with the following command:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight shell"&gt;&lt;code&gt;&lt;span class="nv"&gt;QM_ID&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;9001 &lt;span class="se"&gt;\&lt;/span&gt;
&lt;span class="o"&gt;&amp;amp;&amp;amp;&lt;/span&gt; qm create &lt;span class="nv"&gt;$QM_ID&lt;/span&gt; &lt;span class="nt"&gt;--name&lt;/span&gt; &lt;span class="s2"&gt;"debian12-cloudinit"&lt;/span&gt; &lt;span class="nt"&gt;--memory&lt;/span&gt; 512 &lt;span class="nt"&gt;--cores&lt;/span&gt; 1 &lt;span class="nt"&gt;--net0&lt;/span&gt; virtio,bridge&lt;span class="o"&gt;=&lt;/span&gt;vmbr1 &lt;span class="nt"&gt;--machine&lt;/span&gt; q35 &lt;span class="se"&gt;\&lt;/span&gt;
&lt;span class="o"&gt;&amp;amp;&amp;amp;&lt;/span&gt; qm importdisk &lt;span class="nv"&gt;$QM_ID&lt;/span&gt; debian-12-generic-amd64.qcow2 local-lvm &lt;span class="se"&gt;\&lt;/span&gt;
&lt;span class="o"&gt;&amp;amp;&amp;amp;&lt;/span&gt; qm &lt;span class="nb"&gt;set&lt;/span&gt; &lt;span class="nv"&gt;$QM_ID&lt;/span&gt; &lt;span class="nt"&gt;--scsihw&lt;/span&gt; virtio-scsi-pci &lt;span class="nt"&gt;--scsi0&lt;/span&gt; local-lvm:vm-&lt;span class="nv"&gt;$QM_ID&lt;/span&gt;&lt;span class="nt"&gt;-disk-0&lt;/span&gt; &lt;span class="se"&gt;\&lt;/span&gt;
&lt;span class="o"&gt;&amp;amp;&amp;amp;&lt;/span&gt; qm &lt;span class="nb"&gt;set&lt;/span&gt; &lt;span class="nv"&gt;$QM_ID&lt;/span&gt; &lt;span class="nt"&gt;--boot&lt;/span&gt; c &lt;span class="nt"&gt;--bootdisk&lt;/span&gt; scsi0 &lt;span class="se"&gt;\&lt;/span&gt;
&lt;span class="o"&gt;&amp;amp;&amp;amp;&lt;/span&gt; qm &lt;span class="nb"&gt;set&lt;/span&gt; &lt;span class="nv"&gt;$QM_ID&lt;/span&gt; &lt;span class="nt"&gt;--ide2&lt;/span&gt; local-lvm:cloudinit &lt;span class="se"&gt;\&lt;/span&gt;
&lt;span class="o"&gt;&amp;amp;&amp;amp;&lt;/span&gt; qm &lt;span class="nb"&gt;set&lt;/span&gt; &lt;span class="nv"&gt;$QM_ID&lt;/span&gt; &lt;span class="nt"&gt;--serial0&lt;/span&gt; socket &lt;span class="nt"&gt;--vga&lt;/span&gt; serial0 &lt;span class="se"&gt;\&lt;/span&gt;
&lt;span class="o"&gt;&amp;amp;&amp;amp;&lt;/span&gt; qm &lt;span class="nb"&gt;set&lt;/span&gt; &lt;span class="nv"&gt;$QM_ID&lt;/span&gt; &lt;span class="nt"&gt;--agent&lt;/span&gt; &lt;span class="nv"&gt;enabled&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;1 &lt;span class="se"&gt;\&lt;/span&gt;
&lt;span class="o"&gt;&amp;amp;&amp;amp;&lt;/span&gt; qm template &lt;span class="nv"&gt;$QM_ID&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The template ID (&lt;code&gt;9001&lt;/code&gt;) and name (&lt;code&gt;"debian12-cloudinit"&lt;/code&gt;) can be changed to any arbitrary values. Resources and network settings will be redefined for each copied instance.&lt;/p&gt;

&lt;p&gt;All preparations are done, and now you can use Terraform to manage virtual servers.&lt;/p&gt;

&lt;h2&gt;
  
  
  Terraform
&lt;/h2&gt;

&lt;p&gt;To work with Proxmox via Terraform or OpenTofu, you can use the &lt;a href="https://registry.terraform.io/providers/Telmate/proxmox/latest/docs" rel="noopener noreferrer"&gt;telmate/proxmox provider&lt;/a&gt;.&lt;/p&gt;

&lt;p&gt;For security reasons, it’s recommended to create a separate user with limited permissions. However, in a home environment &lt;strong&gt;with access only from the local network&lt;/strong&gt;, you can skip this step.&lt;/p&gt;

&lt;p&gt;Contents of the &lt;code&gt;provider.tf&lt;/code&gt; file:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight terraform"&gt;&lt;code&gt;&lt;span class="k"&gt;terraform&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="nx"&gt;required_providers&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="nx"&gt;proxmox&lt;/span&gt; &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="nx"&gt;source&lt;/span&gt;  &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;"telmate/proxmox"&lt;/span&gt;
      &lt;span class="nx"&gt;version&lt;/span&gt; &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;"3.0.2-rc03"&lt;/span&gt; &lt;span class="c1"&gt;# latest version at the time of writing: 3.0.2-rc07&lt;/span&gt;
    &lt;span class="p"&gt;}&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;

&lt;span class="k"&gt;provider&lt;/span&gt; &lt;span class="s2"&gt;"proxmox"&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="nx"&gt;pm_api_url&lt;/span&gt;      &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;"https://&lt;/span&gt;&lt;span class="k"&gt;${&lt;/span&gt;&lt;span class="kd"&gt;var&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;pm_host&lt;/span&gt;&lt;span class="k"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;:8006/api2/json"&lt;/span&gt;
  &lt;span class="nx"&gt;pm_user&lt;/span&gt;         &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;"&lt;/span&gt;&lt;span class="k"&gt;${&lt;/span&gt;&lt;span class="kd"&gt;var&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;pm_user&lt;/span&gt;&lt;span class="k"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;@pam"&lt;/span&gt;
  &lt;span class="nx"&gt;pm_password&lt;/span&gt;     &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="kd"&gt;var&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;pm_password&lt;/span&gt;
  &lt;span class="nx"&gt;pm_tls_insecure&lt;/span&gt; &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Contents of the &lt;code&gt;variables.tf&lt;/code&gt; file:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight terraform"&gt;&lt;code&gt;&lt;span class="k"&gt;variable&lt;/span&gt; &lt;span class="s2"&gt;"pm_user"&lt;/span&gt; &lt;span class="p"&gt;{}&lt;/span&gt;
&lt;span class="k"&gt;variable&lt;/span&gt; &lt;span class="s2"&gt;"pm_password"&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;sensitive&lt;/span&gt; &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt;
&lt;span class="k"&gt;variable&lt;/span&gt; &lt;span class="s2"&gt;"pm_host"&lt;/span&gt; &lt;span class="p"&gt;{}&lt;/span&gt;
&lt;span class="k"&gt;variable&lt;/span&gt; &lt;span class="s2"&gt;"ssh_key"&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;default&lt;/span&gt; &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;"~/.ssh/id_rsa.pub"&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;After installing the provider with the &lt;code&gt;terraform init&lt;/code&gt; command, you can describe the infrastructure just like when working with cloud providers.&lt;/p&gt;

&lt;p&gt;You can refer to the previously created cloud template either by name using &lt;code&gt;clone&lt;/code&gt; or by its ID using &lt;code&gt;clone_id&lt;/code&gt;.&lt;/p&gt;

&lt;p&gt;Example of creating a virtual server accessible only on the private network:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight terraform"&gt;&lt;code&gt;&lt;span class="nx"&gt;locals&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="nx"&gt;debian_template&lt;/span&gt;    &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;"debian12-cloudinit"&lt;/span&gt;
  &lt;span class="nx"&gt;debian_template_id&lt;/span&gt; &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="mi"&gt;9001&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;

&lt;span class="k"&gt;resource&lt;/span&gt; &lt;span class="s2"&gt;"proxmox_vm_qemu"&lt;/span&gt; &lt;span class="s2"&gt;"internal-vm"&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="nx"&gt;vmid&lt;/span&gt;        &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="mi"&gt;310&lt;/span&gt;
  &lt;span class="nx"&gt;name&lt;/span&gt;        &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;"internal-vm"&lt;/span&gt;
  &lt;span class="nx"&gt;target_node&lt;/span&gt; &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;"pve-1"&lt;/span&gt;
  &lt;span class="nx"&gt;clone&lt;/span&gt;       &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="kd"&gt;local&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;debian_template&lt;/span&gt;
  &lt;span class="nx"&gt;onboot&lt;/span&gt;      &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;
  &lt;span class="nx"&gt;cpu&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="nx"&gt;cores&lt;/span&gt; &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="mi"&gt;1&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt;
  &lt;span class="nx"&gt;memory&lt;/span&gt;           &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="mi"&gt;512&lt;/span&gt;
  &lt;span class="nx"&gt;boot&lt;/span&gt;             &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;"order=scsi0"&lt;/span&gt;
  &lt;span class="nx"&gt;scsihw&lt;/span&gt;           &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;"virtio-scsi-single"&lt;/span&gt;
  &lt;span class="nx"&gt;agent&lt;/span&gt;            &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="mi"&gt;1&lt;/span&gt;
  &lt;span class="nx"&gt;vm_state&lt;/span&gt;         &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;"running"&lt;/span&gt;
  &lt;span class="nx"&gt;automatic_reboot&lt;/span&gt; &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;

  &lt;span class="nx"&gt;ciupgrade&lt;/span&gt; &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="kc"&gt;false&lt;/span&gt;
  &lt;span class="nx"&gt;ipconfig0&lt;/span&gt; &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;"ip=10.0.2.11/24,gw=10.0.2.1"&lt;/span&gt;
  &lt;span class="nx"&gt;skip_ipv6&lt;/span&gt; &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;
  &lt;span class="nx"&gt;ciuser&lt;/span&gt;    &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;"cloud"&lt;/span&gt;
  &lt;span class="nx"&gt;sshkeys&lt;/span&gt;   &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;file&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="kd"&gt;var&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;ssh_key&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

  &lt;span class="nx"&gt;serial&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="nx"&gt;id&lt;/span&gt; &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="mi"&gt;0&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt;

  &lt;span class="nx"&gt;disks&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="nx"&gt;scsi&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="nx"&gt;scsi0&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="nx"&gt;disk&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
          &lt;span class="nx"&gt;storage&lt;/span&gt; &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;"local-lvm"&lt;/span&gt;
          &lt;span class="nx"&gt;size&lt;/span&gt;    &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;"8G"&lt;/span&gt;
        &lt;span class="p"&gt;}&lt;/span&gt;
      &lt;span class="p"&gt;}&lt;/span&gt;
    &lt;span class="p"&gt;}&lt;/span&gt;
    &lt;span class="nx"&gt;ide&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="nx"&gt;ide1&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="nx"&gt;cloudinit&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
          &lt;span class="nx"&gt;storage&lt;/span&gt; &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;"local-lvm"&lt;/span&gt;
        &lt;span class="p"&gt;}&lt;/span&gt;
      &lt;span class="p"&gt;}&lt;/span&gt;
    &lt;span class="p"&gt;}&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt;

  &lt;span class="nx"&gt;network&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="nx"&gt;id&lt;/span&gt;     &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="mi"&gt;0&lt;/span&gt;
    &lt;span class="nx"&gt;bridge&lt;/span&gt; &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;"vmbr1"&lt;/span&gt;
    &lt;span class="nx"&gt;model&lt;/span&gt;  &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;"virtio"&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;To create a server accessible on the local network, specify an additional bridge and its configuration:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight terraform"&gt;&lt;code&gt;&lt;span class="c1"&gt;# ...&lt;/span&gt;

&lt;span class="k"&gt;resource&lt;/span&gt; &lt;span class="s2"&gt;"proxmox_vm_qemu"&lt;/span&gt; &lt;span class="s2"&gt;"jump-host"&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="nx"&gt;vmid&lt;/span&gt;        &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="mi"&gt;110&lt;/span&gt;
  &lt;span class="nx"&gt;name&lt;/span&gt;        &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;"jump-host"&lt;/span&gt;
  &lt;span class="nx"&gt;target_node&lt;/span&gt; &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;"pve-1"&lt;/span&gt;
  &lt;span class="nx"&gt;clone_id&lt;/span&gt;     &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="kd"&gt;local&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;debian_template_id&lt;/span&gt;
  &lt;span class="c1"&gt;# ...&lt;/span&gt;
  &lt;span class="nx"&gt;ipconfig0&lt;/span&gt; &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;"ip=10.0.2.10/24,gw=10.0.2.1"&lt;/span&gt;
  &lt;span class="nx"&gt;ipconfig1&lt;/span&gt; &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;"ip=dhcp"&lt;/span&gt;

  &lt;span class="c1"&gt;# ...&lt;/span&gt;

  &lt;span class="nx"&gt;network&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="nx"&gt;id&lt;/span&gt;     &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="mi"&gt;0&lt;/span&gt;
    &lt;span class="nx"&gt;bridge&lt;/span&gt; &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;"vmbr1"&lt;/span&gt;
    &lt;span class="nx"&gt;model&lt;/span&gt;  &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;"virtio"&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt;

  &lt;span class="nx"&gt;network&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="nx"&gt;id&lt;/span&gt;      &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="mi"&gt;1&lt;/span&gt;
    &lt;span class="nx"&gt;bridge&lt;/span&gt;  &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;"vmbr0"&lt;/span&gt;
    &lt;span class="nx"&gt;model&lt;/span&gt;   &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;"virtio"&lt;/span&gt;
    &lt;span class="nx"&gt;macaddr&lt;/span&gt; &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;"AA:24:11:75:01:10"&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The VM’s MAC address is fixed to create static IPs on the DHCP server side. The VMs created above are accessible via SSH through the jump host using the &lt;code&gt;cloud&lt;/code&gt; user and the SSH key specified in the&lt;br&gt;
Terraform variables.&lt;/p&gt;
&lt;h2&gt;
  
  
  Working with a PVE Cluster
&lt;/h2&gt;

&lt;p&gt;To manage cluster infrastructure, you can connect to any node’s API. In PVE, there’s no “master” host. By connecting to one node’s API, you can manage resources on other nodes.&lt;/p&gt;

&lt;p&gt;However, if Terraform state includes resources on a powered-off node, TF will fail with an error. Therefore, when using Terraform, all cluster nodes with managed resources must be available.&lt;/p&gt;
&lt;h3&gt;
  
  
  Quorum Error
&lt;/h3&gt;

&lt;p&gt;To simulate distributed systems for testing, I use a cluster of two hosts. Most of the time, I don’t need both PVE hosts, and only one is powered on.&lt;/p&gt;

&lt;p&gt;By default, this approach leads to a “cluster not ready - no quorum?” error and makes Proxmox completely unusable.&lt;/p&gt;

&lt;p&gt;To allow the cluster to work with just one node, run this command:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight shell"&gt;&lt;code&gt;pvecm expect 1
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;To make this setting persistent, add three lines to the &lt;code&gt;/etc/pve/corosync.conf&lt;/code&gt; file:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;# ...

quorum {
  # ... defaults

  expected_votes: 1
  two_node: 0
  wait_for_all: 0
}

# ...
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h3&gt;
  
  
  Working with Templates
&lt;/h3&gt;

&lt;p&gt;Since the VM template image is stored on the local file system, you need to create it on each host.&lt;/p&gt;

&lt;p&gt;Proxmox expects unique server and template IDs at the cluster level, so:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;when preparing a template on each host, you must change its ID;&lt;/li&gt;
&lt;li&gt;when using &lt;code&gt;clone_id&lt;/code&gt; in Terraform, you must specify the template ID located on the specified &lt;code&gt;target_node&lt;/code&gt;.&lt;/li&gt;
&lt;/ul&gt;




&lt;p&gt;&lt;a href="https://mpanichev.ru/articles/proxmox-as-home-cloud/" rel="noopener noreferrer"&gt;RU translation&lt;/a&gt;&lt;/p&gt;

</description>
      <category>proxmox</category>
      <category>devops</category>
      <category>debian</category>
      <category>terraform</category>
    </item>
    <item>
      <title>Declarative rendering of react-query state via switch-query</title>
      <dc:creator>Mikhail Panichev</dc:creator>
      <pubDate>Mon, 09 Feb 2026 00:42:00 +0000</pubDate>
      <link>https://dev.to/denisinvader/declarative-rendering-of-react-query-state-via-switch-query-46lg</link>
      <guid>https://dev.to/denisinvader/declarative-rendering-of-react-query-state-via-switch-query-46lg</guid>
      <description>&lt;p&gt;&lt;a href="https://mpanichev.ru/articles/switch-query-package/" rel="noopener noreferrer"&gt;Russian version&lt;/a&gt;&lt;/p&gt;

&lt;p&gt;&lt;a href="https://github.com/denisinvader/switch-query" rel="noopener noreferrer"&gt;&lt;code&gt;switch-query&lt;/code&gt;&lt;/a&gt; is a tiny &lt;a href="https://www.npmjs.com/package/switch-query" rel="noopener noreferrer"&gt;npm package&lt;/a&gt; that simplifies displaying the state from &lt;a href="https://tanstack.com/query/latest" rel="noopener noreferrer"&gt;&lt;code&gt;@tanstack/react-query&lt;/code&gt;&lt;/a&gt;. It exports a single component, &lt;code&gt;SwitchQuery&lt;/code&gt;, along with its types. Despite its simplicity, the package streamlines code structure and enables more thoughtful design UI/UX.&lt;/p&gt;

&lt;h2&gt;
  
  
  Request states
&lt;/h2&gt;

&lt;p&gt;In general, to provide users with the most accurate information retrieved from the server, the following scenarios must be considered:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;
&lt;strong&gt;Success&lt;/strong&gt; — the request was successful, and data is displayed.&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Failure&lt;/strong&gt; — the request resulted in an error.&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Loading&lt;/strong&gt; — the request is in progress, and data is not yet available.&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Empty state&lt;/strong&gt; — the response was successful, but there is no data.&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;&lt;code&gt;@tanstack/react-query&lt;/code&gt; implements &lt;a href="https://www.typescriptlang.org/docs/handbook/2/narrowing.html" rel="noopener noreferrer"&gt;types narrowing&lt;/a&gt;. This allows you to explicitly separate request states using strict typing.&lt;/p&gt;

&lt;p&gt;Let’s take an example from the official website:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight tsx"&gt;&lt;code&gt;&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;useQuery&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;@tanstack/react-query&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

&lt;span class="kd"&gt;function&lt;/span&gt; &lt;span class="nf"&gt;Todos&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;data&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;isPending&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;error&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;useQuery&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt;
        &lt;span class="na"&gt;queryKey&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;todos&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;
        &lt;span class="na"&gt;queryFn&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="nf"&gt;fetch&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;/api/todos&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;then&lt;/span&gt;&lt;span class="p"&gt;((&lt;/span&gt;&lt;span class="nx"&gt;r&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="nx"&gt;r&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;json&lt;/span&gt;&lt;span class="p"&gt;()),&lt;/span&gt;
    &lt;span class="p"&gt;});&lt;/span&gt;

    &lt;span class="k"&gt;if &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;isPending&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;span&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;Loading...&lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;span&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;;&lt;/span&gt;
    &lt;span class="p"&gt;}&lt;/span&gt;

    &lt;span class="k"&gt;if &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;error&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;span&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;Oops!&lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;span&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;;&lt;/span&gt;
    &lt;span class="p"&gt;}&lt;/span&gt;

    &lt;span class="k"&gt;return &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
        &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;ul&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
            &lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;data&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;map&lt;/span&gt;&lt;span class="p"&gt;((&lt;/span&gt;&lt;span class="nx"&gt;t&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;
                &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;li&lt;/span&gt; &lt;span class="na"&gt;key&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;t&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;id&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;t&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;title&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;li&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
            &lt;span class="p"&gt;))&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
        &lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;ul&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
    &lt;span class="p"&gt;);&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;

&lt;span class="k"&gt;export&lt;/span&gt; &lt;span class="k"&gt;default&lt;/span&gt; &lt;span class="nx"&gt;Todos&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;In my opinion, this is one of the library’s key advantages: it encourages developers to create more thoughtful user interfaces.&lt;/p&gt;

&lt;p&gt;However, when using &lt;code&gt;if&lt;/code&gt; and &lt;code&gt;return&lt;/code&gt; statements, it becomes inconvenient to add elements common to each state. For example, let’s add a container and a create button.&lt;/p&gt;

&lt;p&gt;
  Example of modified code
  &lt;br&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight tsx"&gt;&lt;code&gt;&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;useQuery&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;@tanstack/react-query&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

&lt;span class="kd"&gt;function&lt;/span&gt; &lt;span class="nf"&gt;Todos&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;data&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;isPending&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;error&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;useQuery&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt;
        &lt;span class="na"&gt;queryKey&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;todos&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;
        &lt;span class="na"&gt;queryFn&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="nf"&gt;fetch&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;/api/todos&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;then&lt;/span&gt;&lt;span class="p"&gt;((&lt;/span&gt;&lt;span class="nx"&gt;r&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="nx"&gt;r&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;json&lt;/span&gt;&lt;span class="p"&gt;()),&lt;/span&gt;
    &lt;span class="p"&gt;});&lt;/span&gt;

    &lt;span class="k"&gt;if &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;isPending&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="k"&gt;return &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
            &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;div&lt;/span&gt; &lt;span class="na"&gt;className&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"container"&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
                &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;span&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;Loading...&lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;span&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
                &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;button&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;add&lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;button&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
            &lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;div&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
        &lt;span class="p"&gt;);&lt;/span&gt;
    &lt;span class="p"&gt;}&lt;/span&gt;

    &lt;span class="k"&gt;if &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;error&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="k"&gt;return &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
            &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;div&lt;/span&gt; &lt;span class="na"&gt;className&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"container"&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
                &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;span&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;Oops!&lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;span&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
                &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;button&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;add&lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;button&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
            &lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;div&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
        &lt;span class="p"&gt;);&lt;/span&gt;
    &lt;span class="p"&gt;}&lt;/span&gt;

    &lt;span class="k"&gt;return &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
        &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;div&lt;/span&gt; &lt;span class="na"&gt;className&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"container"&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
            &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;ul&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
                &lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;data&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;map&lt;/span&gt;&lt;span class="p"&gt;((&lt;/span&gt;&lt;span class="nx"&gt;t&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;
                    &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;li&lt;/span&gt; &lt;span class="na"&gt;key&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;t&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;id&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;t&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;title&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;li&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
                &lt;span class="p"&gt;))&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
            &lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;ul&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
            &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;button&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;add&lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;button&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
        &lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;div&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
    &lt;span class="p"&gt;);&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;

&lt;span class="k"&gt;export&lt;/span&gt; &lt;span class="k"&gt;default&lt;/span&gt; &lt;span class="nx"&gt;Todos&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;


&lt;p&gt;An alternative using conditions within JSX solves the code duplication issue but is less explicit and leaves room for errors, such as displaying multiple states simultaneously:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight tsx"&gt;&lt;code&gt;&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;useQuery&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;@tanstack/react-query&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

&lt;span class="kd"&gt;function&lt;/span&gt; &lt;span class="nf"&gt;Todos&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;data&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;isPending&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;error&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;isSuccess&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;useQuery&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt;
        &lt;span class="na"&gt;queryKey&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;todos&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;
        &lt;span class="na"&gt;queryFn&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="nf"&gt;fetch&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;/api/todos&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;then&lt;/span&gt;&lt;span class="p"&gt;((&lt;/span&gt;&lt;span class="nx"&gt;r&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="nx"&gt;r&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;json&lt;/span&gt;&lt;span class="p"&gt;()),&lt;/span&gt;
    &lt;span class="p"&gt;});&lt;/span&gt;

    &lt;span class="k"&gt;return &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
        &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;div&lt;/span&gt; &lt;span class="na"&gt;className&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"container"&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
            &lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;isPending&lt;/span&gt; &lt;span class="o"&gt;&amp;amp;&amp;amp;&lt;/span&gt; &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;span&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;Loading...&lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;span&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;

            &lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;error&lt;/span&gt; &lt;span class="o"&gt;&amp;amp;&amp;amp;&lt;/span&gt; &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;span&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;Oops!&lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;span&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;

            &lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;isSuccess&lt;/span&gt; &lt;span class="o"&gt;&amp;amp;&amp;amp;&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;
                &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;ul&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
                    &lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;data&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;map&lt;/span&gt;&lt;span class="p"&gt;((&lt;/span&gt;&lt;span class="nx"&gt;t&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;
                        &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;li&lt;/span&gt; &lt;span class="na"&gt;key&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;t&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;id&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;t&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;title&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;li&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
                    &lt;span class="p"&gt;))&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
                &lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;ul&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
            &lt;span class="p"&gt;)&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
            &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;button&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;add&lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;button&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
        &lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;div&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
    &lt;span class="p"&gt;);&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;

&lt;span class="k"&gt;export&lt;/span&gt; &lt;span class="k"&gt;default&lt;/span&gt; &lt;span class="nx"&gt;Todos&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;





&lt;br&gt;
&lt;/p&gt;

&lt;p&gt;With &lt;code&gt;switch-query&lt;/code&gt;, this task is easily solved by encapsulating checks within a nested JSX element:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight tsx"&gt;&lt;code&gt;&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;useQuery&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;@tanstack/react-query&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;SwitchQuery&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;switch-query&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

&lt;span class="kd"&gt;function&lt;/span&gt; &lt;span class="nf"&gt;Todos&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;query&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;useQuery&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt;
        &lt;span class="na"&gt;queryKey&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;todos&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;
        &lt;span class="na"&gt;queryFn&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="nf"&gt;fetch&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;/api/todos&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;then&lt;/span&gt;&lt;span class="p"&gt;((&lt;/span&gt;&lt;span class="nx"&gt;r&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="nx"&gt;r&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;json&lt;/span&gt;&lt;span class="p"&gt;()),&lt;/span&gt;
    &lt;span class="p"&gt;});&lt;/span&gt;

    &lt;span class="k"&gt;return &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
        &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;div&lt;/span&gt; &lt;span class="na"&gt;className&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"container"&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
            &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nc"&gt;SwitchQuery&lt;/span&gt;
                &lt;span class="na"&gt;query&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;query&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
                &lt;span class="na"&gt;pending&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;span&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;Loading...&lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;span&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
                &lt;span class="na"&gt;error&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;span&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;Oops!&lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;span&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
                &lt;span class="na"&gt;success&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt; &lt;span class="nx"&gt;data&lt;/span&gt; &lt;span class="p"&gt;})&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;
                    &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;ul&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
                        &lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;data&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;map&lt;/span&gt;&lt;span class="p"&gt;((&lt;/span&gt;&lt;span class="nx"&gt;t&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;
                            &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;li&lt;/span&gt; &lt;span class="na"&gt;key&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;t&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;id&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;t&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;title&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;li&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
                        &lt;span class="p"&gt;))&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
                    &lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;ul&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
                &lt;span class="p"&gt;)&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
            &lt;span class="p"&gt;/&amp;gt;&lt;/span&gt;
            &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;button&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;add&lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;button&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
        &lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;div&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
    &lt;span class="p"&gt;);&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;

&lt;span class="k"&gt;export&lt;/span&gt; &lt;span class="k"&gt;default&lt;/span&gt; &lt;span class="nx"&gt;Todos&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;This approach is more convenient in the JSX context. There’s no need to excessively decompose components or use nested ternary operators.&lt;/p&gt;

&lt;h2&gt;
  
  
  Multiple queries in a single component
&lt;/h2&gt;

&lt;p&gt;Rendering via JSX allows working with multiple queries in a single component.&lt;/p&gt;

&lt;p&gt;Suppose each item references a tag dictionary via &lt;code&gt;tagId&lt;/code&gt;, and we need to display the tag title.&lt;/p&gt;

&lt;p&gt;In this case, you can nest &lt;code&gt;&amp;lt;SwitchQuery /&amp;gt;&lt;/code&gt; elements within each other. The order in which responses are received doesn’t matter, as all states are accounted for at every level.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight tsx"&gt;&lt;code&gt;&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;useQuery&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;@tanstack/react-query&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;SwitchQuery&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;switch-query&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

&lt;span class="kd"&gt;function&lt;/span&gt; &lt;span class="nf"&gt;Todos&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;todos&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;useQuery&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt;
        &lt;span class="na"&gt;queryKey&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;todos&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;
        &lt;span class="na"&gt;queryFn&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="nf"&gt;fetch&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;/api/todos&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;then&lt;/span&gt;&lt;span class="p"&gt;((&lt;/span&gt;&lt;span class="nx"&gt;r&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="nx"&gt;r&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;json&lt;/span&gt;&lt;span class="p"&gt;()),&lt;/span&gt;
    &lt;span class="p"&gt;});&lt;/span&gt;
    &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;tags&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;useQuery&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt;
        &lt;span class="na"&gt;queryKey&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;tags&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;
        &lt;span class="na"&gt;queryFn&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="nf"&gt;fetch&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;/api/tags&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;then&lt;/span&gt;&lt;span class="p"&gt;((&lt;/span&gt;&lt;span class="nx"&gt;r&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="nx"&gt;r&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;json&lt;/span&gt;&lt;span class="p"&gt;()),&lt;/span&gt;
    &lt;span class="p"&gt;});&lt;/span&gt;

    &lt;span class="k"&gt;return &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
        &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;div&lt;/span&gt; &lt;span class="na"&gt;className&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"container"&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
            &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nc"&gt;SwitchQuery&lt;/span&gt;
                &lt;span class="na"&gt;query&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;todos&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
                &lt;span class="na"&gt;pending&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;span&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;Loading...&lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;span&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
                &lt;span class="na"&gt;error&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;span&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;Oops!&lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;span&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
                &lt;span class="na"&gt;success&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt; &lt;span class="nx"&gt;data&lt;/span&gt; &lt;span class="p"&gt;})&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;
                    &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;ul&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
                        &lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;data&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;map&lt;/span&gt;&lt;span class="p"&gt;((&lt;/span&gt;&lt;span class="nx"&gt;t&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;
                            &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;li&lt;/span&gt; &lt;span class="na"&gt;key&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;t&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;id&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
                                &lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;t&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;title&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
                                &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nc"&gt;SwitchQuery&lt;/span&gt;
                                    &lt;span class="na"&gt;query&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;tags&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
                                    &lt;span class="na"&gt;success&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt; &lt;span class="nx"&gt;data&lt;/span&gt; &lt;span class="p"&gt;})&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="nx"&gt;data&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;title&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
                                    &lt;span class="na"&gt;pending&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"loading..."&lt;/span&gt;
                                    &lt;span class="na"&gt;error&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="s2"&gt;`#&lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="nx"&gt;t&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;tagId&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;`&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
                                &lt;span class="p"&gt;/&amp;gt;&lt;/span&gt;
                            &lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;li&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
                        &lt;span class="p"&gt;))&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
                    &lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;ul&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
                &lt;span class="p"&gt;)&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
            &lt;span class="p"&gt;/&amp;gt;&lt;/span&gt;
            &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;button&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;add&lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;button&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;

            &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;div&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
                &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;h2&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;Tags:&lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;h2&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
                &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nc"&gt;SwitchQuery&lt;/span&gt;
                    &lt;span class="na"&gt;query&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;tags&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
                    &lt;span class="na"&gt;success&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt; &lt;span class="nx"&gt;data&lt;/span&gt; &lt;span class="p"&gt;})&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;
                        &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;ul&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
                            &lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nb"&gt;Object&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;keys&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;data&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;map&lt;/span&gt;&lt;span class="p"&gt;((&lt;/span&gt;&lt;span class="nx"&gt;id&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;
                                &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;li&lt;/span&gt; &lt;span class="na"&gt;key&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;id&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;data&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;title&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;li&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
                            &lt;span class="p"&gt;))&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
                        &lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;ul&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
                    &lt;span class="p"&gt;)&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
                    &lt;span class="na"&gt;pending&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"loading..."&lt;/span&gt;
                    &lt;span class="na"&gt;error&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt; &lt;span class="nx"&gt;error&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;refetch&lt;/span&gt; &lt;span class="p"&gt;})&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;
                        &lt;span class="p"&gt;&amp;lt;&amp;gt;&lt;/span&gt;
                            &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;div&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;error&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;message&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;div&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
                            &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;button&lt;/span&gt; &lt;span class="na"&gt;onClick&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="nf"&gt;refetch&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;retry&lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;button&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
                        &lt;span class="p"&gt;&amp;lt;/&amp;gt;&lt;/span&gt;
                    &lt;span class="p"&gt;)&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
                &lt;span class="p"&gt;/&amp;gt;&lt;/span&gt;
            &lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;div&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
        &lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;div&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
    &lt;span class="p"&gt;);&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;

&lt;span class="k"&gt;export&lt;/span&gt; &lt;span class="k"&gt;default&lt;/span&gt; &lt;span class="nx"&gt;Todos&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Implementing such a view without &lt;code&gt;switch-query&lt;/code&gt; would require creating additional components.&lt;/p&gt;

&lt;h2&gt;
  
  
  Empty states
&lt;/h2&gt;

&lt;p&gt;For good design, it’s also important to explicitly inform the user when there is no data.&lt;/p&gt;

&lt;p&gt;In &lt;code&gt;switch-query&lt;/code&gt; empty state case is moved to additional props:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight tsx"&gt;&lt;code&gt;&lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nc"&gt;SwitchQuery&lt;/span&gt;
    &lt;span class="na"&gt;query&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;query&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
    &lt;span class="na"&gt;success&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt; &lt;span class="nx"&gt;data&lt;/span&gt; &lt;span class="p"&gt;})&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;
        &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;ul&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
            &lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;data&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;map&lt;/span&gt;&lt;span class="p"&gt;((&lt;/span&gt;&lt;span class="nx"&gt;t&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;
                &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;li&lt;/span&gt; &lt;span class="na"&gt;key&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;t&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;id&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;t&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;title&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;li&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
            &lt;span class="p"&gt;))&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
        &lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;ul&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
    &lt;span class="p"&gt;)&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
    &lt;span class="na"&gt;checkIsEmpty&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;data&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="o"&gt;!&lt;/span&gt;&lt;span class="nx"&gt;data&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;length&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
    &lt;span class="na"&gt;empty&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;div&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;Nothing to do&lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;div&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
&lt;span class="p"&gt;/&amp;gt;&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Handling all possible states is brought to a more declarative style.&lt;/p&gt;

&lt;h2&gt;
  
  
  Conclusion
&lt;/h2&gt;

&lt;p&gt;One might argue that all the examples above are flawed and it would be better to move everything into separate components. This is a perfectly valid stance and you could even use &lt;code&gt;useSuspenseQuery&lt;/code&gt;. &lt;/p&gt;

&lt;p&gt;However, in this case, implementation of a single interface block would be spread across multiple components and files, which would also need to be named.&lt;/p&gt;

&lt;p&gt;I believe that &lt;code&gt;@tanstack/react-query&lt;/code&gt; blurs established patterns by making the request an integral part of the views, which aligns with the final result. The library’s declarative API is perfectly complemented by the declarative nature of JSX.&lt;/p&gt;

&lt;p&gt;&lt;a href="https://github.com/denisinvader/switch-query" rel="noopener noreferrer"&gt;Star on GitHub&lt;/a&gt;&lt;/p&gt;

</description>
      <category>react</category>
      <category>reactquery</category>
    </item>
    <item>
      <title>Do you know the software to host a webinar?</title>
      <dc:creator>Mikhail Panichev</dc:creator>
      <pubDate>Thu, 19 Mar 2020 12:12:39 +0000</pubDate>
      <link>https://dev.to/denisinvader/do-you-know-the-software-to-host-a-webinar-59if</link>
      <guid>https://dev.to/denisinvader/do-you-know-the-software-to-host-a-webinar-59if</guid>
      <description>&lt;p&gt;Hi everyone!&lt;/p&gt;

&lt;p&gt;Because of COVID-19 my client's trainers are restricted to go to business trips but have to land the same count of workshops annually.&lt;/p&gt;

&lt;p&gt;So we decided to use a platform for webinars to do those workshops remotely but we can't find a solution.&lt;/p&gt;

&lt;p&gt;We checked out YouTube Live and some SAAS solutions but they don't meet the client's requirements.&lt;/p&gt;

&lt;p&gt;What we need:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;Ability to integrate all functionality (video stream, chat room, etc.) to our website;&lt;/li&gt;
&lt;li&gt;Ability to record webinars and host those videos on our website in the archive;&lt;/li&gt;
&lt;li&gt;Ability to style UI of the player and chat (branding);&lt;/li&gt;
&lt;li&gt;The solution can be paid or some OSS projects as well;&lt;/li&gt;
&lt;li&gt;The client doesn't want to show any attribution (I, personally, think that it's okay and even great to show solution attribution).&lt;/li&gt;
&lt;/ul&gt;

</description>
      <category>question</category>
    </item>
    <item>
      <title>Easy data animations in Vue with Vuenime</title>
      <dc:creator>Mikhail Panichev</dc:creator>
      <pubDate>Mon, 16 Sep 2019 22:41:01 +0000</pubDate>
      <link>https://dev.to/denisinvader/easy-data-animations-in-vue-with-vuenime-1b1g</link>
      <guid>https://dev.to/denisinvader/easy-data-animations-in-vue-with-vuenime-1b1g</guid>
      <description>&lt;p&gt;Few times in a row I have been creating data visualizations with animations that incapable of CSS transitions. Every time I implemented all animation logic from scratch using &lt;a href="https://animejs.com" rel="noopener noreferrer"&gt;Animejs&lt;/a&gt;. &lt;br&gt;
Except for the last one when I realized that the combination of the &lt;code&gt;watch&lt;/code&gt; property and &lt;code&gt;anime&lt;/code&gt; call can provide a simple way to create a wrapper component for declarative animations. &lt;/p&gt;

&lt;p&gt;And I wrote it. &lt;/p&gt;

&lt;p&gt;Then I discovered that there are no such packages in npm. Okay, there is &lt;a href="https://www.npmjs.com/package/vue-animejs" rel="noopener noreferrer"&gt;vue-anime&lt;/a&gt; but it just adds &lt;code&gt;$anime&lt;/code&gt; to Vue prototype and provides &lt;code&gt;v-anime&lt;/code&gt; directive (which is limited to DOM node; also I don't use directives at all because of JSX).&lt;/p&gt;

&lt;p&gt;And I made an npm package.&lt;/p&gt;

&lt;p&gt;Frankly, it was a long process of finding free time, deciding how to provide documentation, which features are necessary for release, and so on. But I turned off the perfectionism and here it is!&lt;/p&gt;

&lt;p&gt;I hope you find this package useful and give me some feedback!&lt;/p&gt;

&lt;p&gt;&lt;a href="https://www.npmjs.com/package/vuenime" rel="noopener noreferrer"&gt;NPM Package&lt;/a&gt;&lt;br&gt;
&lt;a href="https://github.com/denisinvader/vuenime" rel="noopener noreferrer"&gt;GitHub Repo&lt;/a&gt;&lt;br&gt;
&lt;a href="//denisinvader.github.io/vuenime/"&gt;Storybook&lt;/a&gt;&lt;/p&gt;

</description>
      <category>showdev</category>
      <category>vue</category>
      <category>javascript</category>
    </item>
    <item>
      <title>Vue-emit: an npm package to dispatch events in Vue.js</title>
      <dc:creator>Mikhail Panichev</dc:creator>
      <pubDate>Sun, 21 Oct 2018 11:49:35 +0000</pubDate>
      <link>https://dev.to/denisinvader/vue-emit-an-npm-package-to-dispatch-events-in-vuejs-2a4f</link>
      <guid>https://dev.to/denisinvader/vue-emit-an-npm-package-to-dispatch-events-in-vuejs-2a4f</guid>
      <description>&lt;p&gt;&lt;a href="https://github.com/denisinvader/vue-emit" rel="noopener noreferrer"&gt;Source code&lt;/a&gt; | &lt;a href="https://www.npmjs.com/package/vue-emit" rel="noopener noreferrer"&gt;NPM&lt;/a&gt;&lt;/p&gt;

&lt;p&gt;Vue.js provides an API for dispatching events in components by &lt;code&gt;this.$emit&lt;/code&gt;. But in functional components, you don't have &lt;code&gt;this&lt;/code&gt; instance at all and many people who didn't previously worked with functional components, ask "How to emit an event in a functional component?"&lt;/p&gt;

&lt;p&gt;The first solution is to use props for event listeners. It such a React way. The problem that in this case, you have strictly defined event name, can't use &lt;code&gt;@&lt;/code&gt; / &lt;code&gt;v-on&lt;/code&gt; / &lt;code&gt;v-model&lt;/code&gt; syntax and have some additional difficulties in implementing &lt;a href="https://www.vuemastery.com/conferences/vueconf-2018/7-secret-patterns-vue-consultants-dont-want-you-to-know-chris-fritz/" rel="noopener noreferrer"&gt;transparent wrappers&lt;/a&gt;. Example:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight jsx"&gt;&lt;code&gt;&lt;span class="c1"&gt;// Child component&lt;/span&gt;
&lt;span class="k"&gt;export&lt;/span&gt; &lt;span class="k"&gt;default&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;base-input&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="na"&gt;functional&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="na"&gt;props&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="na"&gt;onInput&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="na"&gt;type&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;Function&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
      &lt;span class="na"&gt;default&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;(),&lt;/span&gt;
    &lt;span class="p"&gt;},&lt;/span&gt;
  &lt;span class="p"&gt;},&lt;/span&gt;
  &lt;span class="nf"&gt;render &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;h&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;context&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="k"&gt;return &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
      &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;input&lt;/span&gt;
        &lt;span class="na"&gt;onInput&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;context&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;props&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;onInput&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
        &lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="p"&gt;...{&lt;/span&gt;
          &lt;span class="nl"&gt;attrs&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;context&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;data&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;attrs&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
          &lt;span class="nx"&gt;on&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;context&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;listeners&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
      &lt;span class="p"&gt;/&amp;gt;&lt;/span&gt;
    &lt;span class="p"&gt;);&lt;/span&gt;
  &lt;span class="p"&gt;},&lt;/span&gt;
&lt;span class="p"&gt;};&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight vue"&gt;&lt;code&gt;&lt;span class="c"&gt;&amp;lt;!-- Parent component template --&amp;gt;&lt;/span&gt;
&lt;span class="nt"&gt;&amp;lt;&lt;/span&gt;&lt;span class="k"&gt;template&lt;/span&gt;&lt;span class="nt"&gt;&amp;gt;&lt;/span&gt;
  &lt;span class="nt"&gt;&amp;lt;base-input&lt;/span&gt; &lt;span class="na"&gt;onInput=&lt;/span&gt;&lt;span class="s"&gt;"doSomething"&lt;/span&gt; &lt;span class="nt"&gt;/&amp;gt;&lt;/span&gt;
&lt;span class="nt"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="k"&gt;template&lt;/span&gt;&lt;span class="nt"&gt;&amp;gt;&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;


&lt;p&gt;The second solution is to use &lt;code&gt;context.listeners&lt;/code&gt;. This is a good way to dispatch an event in Vue.js. Example:&lt;br&gt;
&lt;/p&gt;
&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight jsx"&gt;&lt;code&gt;&lt;span class="c1"&gt;// Child component&lt;/span&gt;
&lt;span class="k"&gt;export&lt;/span&gt; &lt;span class="k"&gt;default&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;base-input&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="na"&gt;functional&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="nf"&gt;render &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;h&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;context&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="k"&gt;return &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
      &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;input&lt;/span&gt;
        &lt;span class="na"&gt;onInput&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;e&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="nx"&gt;context&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;listeners&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;input&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;e&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;target&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;value&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
        &lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="p"&gt;...{&lt;/span&gt;
          &lt;span class="nl"&gt;attrs&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;context&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;data&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;attrs&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
          &lt;span class="nx"&gt;on&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;context&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;listeners&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
      &lt;span class="p"&gt;/&amp;gt;&lt;/span&gt;
    &lt;span class="p"&gt;);&lt;/span&gt;
  &lt;span class="p"&gt;},&lt;/span&gt;
&lt;span class="p"&gt;};&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight vue"&gt;&lt;code&gt;&lt;span class="c"&gt;&amp;lt;!-- Parent component template --&amp;gt;&lt;/span&gt;
&lt;span class="nt"&gt;&amp;lt;&lt;/span&gt;&lt;span class="k"&gt;template&lt;/span&gt;&lt;span class="nt"&gt;&amp;gt;&lt;/span&gt;
  &lt;span class="nt"&gt;&amp;lt;base-input&lt;/span&gt; &lt;span class="err"&gt;@&lt;/span&gt;&lt;span class="na"&gt;input=&lt;/span&gt;&lt;span class="s"&gt;"doSomething"&lt;/span&gt; &lt;span class="nt"&gt;/&amp;gt;&lt;/span&gt;
&lt;span class="nt"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="k"&gt;template&lt;/span&gt;&lt;span class="nt"&gt;&amp;gt;&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;


&lt;p&gt;But there are some pitfalls when using &lt;code&gt;context.listeners&lt;/code&gt;. I've found two situations when you will get &lt;code&gt;TypeError: context.listeners.yourEvent is not a function&lt;/code&gt;&lt;/p&gt;
&lt;h3&gt;
  
  
  1. Listener can be &lt;code&gt;undefined&lt;/code&gt; (not proveded)
&lt;/h3&gt;

&lt;p&gt;If you don't pass a listener from the parent component, there is no handler for the event (input event in our case) in &lt;code&gt;context.listeners&lt;/code&gt; object.&lt;/p&gt;
&lt;h3&gt;
  
  
  2. Listener value can be a function
&lt;/h3&gt;

&lt;p&gt;&lt;a href="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Farticles%2Fzdmg3pfo5o5h7osf438j.jpg" class="article-body-image-wrapper"&gt;&lt;img src="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Farticles%2Fzdmg3pfo5o5h7osf438j.jpg" alt="Components structure example" width="792" height="660"&gt;&lt;/a&gt;&lt;/p&gt;

&lt;p&gt;The picture above shows the example structure of components and listeners. It this structure &lt;code&gt;context.listeners.input&lt;/code&gt; in the C component will be an array of two functions: &lt;code&gt;[doSomethingA, doSomethingB]&lt;/code&gt;. This is also true for &lt;code&gt;this.$listeners&lt;/code&gt;.&lt;/p&gt;

&lt;p&gt;So when using &lt;code&gt;context.listeners&lt;/code&gt; (either directly calling handlers from &lt;code&gt;this.$listeners&lt;/code&gt;) you have to always check that listener exists and what type it has: Function or Array.&lt;/p&gt;
&lt;h3&gt;
  
  
  Using vue-emit
&lt;/h3&gt;

&lt;p&gt;To solve above problems I've wrote the helper function that do all checks and provides the API similar to &lt;code&gt;$emit&lt;/code&gt;. Thats how to use it:&lt;br&gt;
&lt;/p&gt;
&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight shell"&gt;&lt;code&gt;yarn add vue-emit
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight jsx"&gt;&lt;code&gt;&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="nx"&gt;emit&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;vue-emit&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

&lt;span class="k"&gt;export&lt;/span&gt; &lt;span class="k"&gt;default&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;base-input&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="na"&gt;functional&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="nf"&gt;render &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;h&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;context&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="k"&gt;return &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
      &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;input&lt;/span&gt;
        &lt;span class="na"&gt;onInput&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;e&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="nf"&gt;emit&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;context&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;listeners&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;input&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;e&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;target&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;value&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
      &lt;span class="p"&gt;/&amp;gt;&lt;/span&gt;
    &lt;span class="p"&gt;);&lt;/span&gt;
  &lt;span class="p"&gt;},&lt;/span&gt;
&lt;span class="p"&gt;};&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;


&lt;p&gt;The first argument is an object of listeners with &lt;code&gt;eventName =&amp;gt; handler&lt;/code&gt; structure. It is a standard Vue &lt;code&gt;this.$listeners&lt;/code&gt; and &lt;code&gt;context.listeners&lt;/code&gt; objects.&lt;/p&gt;

&lt;p&gt;The second argument is an event name. Vue-emit will check listeners object and do nothing if handler is not defined or will call each handler if there are more than one listener.&lt;/p&gt;

&lt;p&gt;You can also pass any amount of additional parameters and they all will be passed to handler. By the way, this is the use case with stateful components - when for some reason, you want to pass more than one argument to handler function as a payload.&lt;/p&gt;
&lt;h2&gt;
  
  
  Conclusion
&lt;/h2&gt;

&lt;p&gt;I hope you will find this package useful and enjoyed reading this article. Feel free to ask your questions, open issues, pull request etc. &lt;/p&gt;


&lt;div class="ltag-github-readme-tag"&gt;
  &lt;div class="readme-overview"&gt;
    &lt;h2&gt;
      &lt;img src="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fassets.dev.to%2Fassets%2Fgithub-logo-5a155e1f9a670af7944dd5e12375bc76ed542ea80224905ecaf878b9157cdefc.svg" alt="GitHub logo"&gt;
      &lt;a href="https://github.com/denisinvader" rel="noopener noreferrer"&gt;
        denisinvader
      &lt;/a&gt; / &lt;a href="https://github.com/denisinvader/vue-emit" rel="noopener noreferrer"&gt;
        vue-emit
      &lt;/a&gt;
    &lt;/h2&gt;
    &lt;h3&gt;
      Helper function for emitting events in Vue.js (functional) components
    &lt;/h3&gt;
  &lt;/div&gt;
  &lt;div class="ltag-github-body"&gt;
    
&lt;div id="readme" class="md"&gt;
&lt;div class="markdown-heading"&gt;
&lt;h1 class="heading-element"&gt;Vue emit&lt;/h1&gt;
&lt;/div&gt;

&lt;p&gt;Helper function to emit events from Vue.js functional components. Can be used in regular components too
&lt;a href="https://codesandbox.io/s/71pnzj8qrq" rel="nofollow noopener noreferrer"&gt;CodeSandbox demo&lt;/a&gt;&lt;/p&gt;
&lt;div class="markdown-heading"&gt;
&lt;h2 class="heading-element"&gt;Installation&lt;/h2&gt;
&lt;/div&gt;
&lt;div class="highlight highlight-source-shell notranslate position-relative overflow-auto js-code-highlight"&gt;
&lt;pre&gt;yarn add vue-emit
&lt;span class="pl-c"&gt;&lt;span class="pl-c"&gt;#&lt;/span&gt; or&lt;/span&gt;
npm install vue-emit&lt;/pre&gt;

&lt;/div&gt;
&lt;div class="markdown-heading"&gt;
&lt;h2 class="heading-element"&gt;Usage&lt;/h2&gt;

&lt;/div&gt;
&lt;div class="highlight highlight-source-js notranslate position-relative overflow-auto js-code-highlight"&gt;
&lt;pre&gt;&lt;span class="pl-k"&gt;import&lt;/span&gt; &lt;span class="pl-s1"&gt;emit&lt;/span&gt; &lt;span class="pl-k"&gt;from&lt;/span&gt; &lt;span class="pl-s"&gt;'vue-emit'&lt;/span&gt;&lt;span class="pl-kos"&gt;;&lt;/span&gt;

&lt;span class="pl-k"&gt;export&lt;/span&gt; &lt;span class="pl-k"&gt;default&lt;/span&gt; &lt;span class="pl-kos"&gt;{&lt;/span&gt;
  &lt;span class="pl-c1"&gt;functional&lt;/span&gt;: &lt;span class="pl-c1"&gt;true&lt;/span&gt;&lt;span class="pl-kos"&gt;,&lt;/span&gt;
  &lt;span class="pl-en"&gt;render&lt;/span&gt; &lt;span class="pl-kos"&gt;(&lt;/span&gt;&lt;span class="pl-s1"&gt;h&lt;/span&gt;&lt;span class="pl-kos"&gt;,&lt;/span&gt; &lt;span class="pl-s1"&gt;context&lt;/span&gt;&lt;span class="pl-kos"&gt;)&lt;/span&gt; &lt;span class="pl-kos"&gt;{&lt;/span&gt;
    &lt;span class="pl-k"&gt;return&lt;/span&gt; &lt;span class="pl-kos"&gt;(&lt;/span&gt;
      &lt;span class="pl-c1"&gt;&amp;lt;&lt;/span&gt;&lt;span class="pl-s1"&gt;button&lt;/span&gt;
        &lt;span class="pl-c1"&gt;onClick&lt;/span&gt;&lt;span class="pl-c1"&gt;=&lt;/span&gt;&lt;span class="pl-kos"&gt;{&lt;/span&gt;&lt;span class="pl-s1"&gt;e&lt;/span&gt; &lt;span class="pl-c1"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="pl-en"&gt;emit&lt;/span&gt;&lt;span class="pl-kos"&gt;(&lt;/span&gt;&lt;span class="pl-s1"&gt;context&lt;/span&gt;&lt;span class="pl-kos"&gt;.&lt;/span&gt;&lt;span class="pl-c1"&gt;listeners&lt;/span&gt;&lt;span class="pl-kos"&gt;,&lt;/span&gt; &lt;span class="pl-s"&gt;'someEvent'&lt;/span&gt;&lt;span class="pl-kos"&gt;,&lt;/span&gt; &lt;span class="pl-s1"&gt;e&lt;/span&gt;&lt;span class="pl-kos"&gt;,&lt;/span&gt; &lt;span class="pl-s"&gt;'additional param'&lt;/span&gt;&lt;span class="pl-kos"&gt;,&lt;/span&gt; &lt;span class="pl-s"&gt;'etc'&lt;/span&gt;&lt;span class="pl-kos"&gt;)&lt;/span&gt;&lt;span class="pl-kos"&gt;}&lt;/span&gt;
      &lt;span class="pl-c1"&gt;&amp;gt;&lt;/span&gt;
        &lt;span class="pl-kos"&gt;{&lt;/span&gt;&lt;span class="pl-s1"&gt;context&lt;/span&gt;&lt;span class="pl-kos"&gt;.&lt;/span&gt;&lt;span class="pl-c1"&gt;children&lt;/span&gt;&lt;span class="pl-kos"&gt;}&lt;/span&gt;
      &lt;span class="pl-kos"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="pl-s1"&gt;button&lt;/span&gt;&lt;span class="pl-c1"&gt;&amp;gt;&lt;/span&gt;
    &lt;span class="pl-kos"&gt;)&lt;/span&gt;&lt;span class="pl-kos"&gt;;&lt;/span&gt;
  &lt;span class="pl-kos"&gt;}&lt;/span&gt;&lt;span class="pl-kos"&gt;,&lt;/span&gt;
&lt;span class="pl-kos"&gt;}&lt;/span&gt;&lt;span class="pl-kos"&gt;;&lt;/span&gt;&lt;/pre&gt;

&lt;/div&gt;
&lt;div class="markdown-heading"&gt;
&lt;h2 class="heading-element"&gt;Params&lt;/h2&gt;

&lt;/div&gt;
&lt;div class="highlight highlight-source-js notranslate position-relative overflow-auto js-code-highlight"&gt;
&lt;pre&gt;&lt;span class="pl-en"&gt;emit&lt;/span&gt;&lt;span class="pl-kos"&gt;(&lt;/span&gt;&lt;span class="pl-s1"&gt;handlers_list&lt;/span&gt;&lt;span class="pl-kos"&gt;,&lt;/span&gt; &lt;span class="pl-s1"&gt;event_name&lt;/span&gt;&lt;span class="pl-kos"&gt;,&lt;/span&gt; &lt;span class="pl-kos"&gt;[&lt;/span&gt;&lt;span class="pl-s1"&gt;optional_payload&lt;/span&gt;&lt;span class="pl-kos"&gt;]&lt;/span&gt;&lt;span class="pl-kos"&gt;)&lt;/span&gt;&lt;span class="pl-kos"&gt;;&lt;/span&gt;&lt;/pre&gt;

&lt;/div&gt;
&lt;ul&gt;
&lt;li&gt;
&lt;p&gt;&lt;code&gt;handlers_list&lt;/code&gt; - object of functions. In Vue this is &lt;code&gt;this.$listeners&lt;/code&gt; and &lt;code&gt;context.listeners&lt;/code&gt; (for funtional components). Each value may be a function or an array of functions. In case of array &lt;code&gt;emit&lt;/code&gt; will call all provided callbacks.&lt;/p&gt;
&lt;/li&gt;
&lt;li&gt;
&lt;p&gt;&lt;code&gt;event_name&lt;/code&gt; - name of the event to fire. The event may not be…&lt;/p&gt;
&lt;/li&gt;
&lt;/ul&gt;
&lt;/div&gt;
  &lt;/div&gt;
  &lt;div class="gh-btn-container"&gt;&lt;a class="gh-btn" href="https://github.com/denisinvader/vue-emit" rel="noopener noreferrer"&gt;View on GitHub&lt;/a&gt;&lt;/div&gt;
&lt;/div&gt;


&lt;p&gt;Photo by Daniele Riggi on Unsplash&lt;/p&gt;

</description>
      <category>javascript</category>
      <category>vue</category>
      <category>npm</category>
      <category>showdev</category>
    </item>
    <item>
      <title>Mounted and BeforeDestroy Hooks in Vue.js functional components.</title>
      <dc:creator>Mikhail Panichev</dc:creator>
      <pubDate>Sun, 21 Oct 2018 09:39:47 +0000</pubDate>
      <link>https://dev.to/denisinvader/mounted-and-beforedestroy-hooks-in-vuejs-functional-components-7bi</link>
      <guid>https://dev.to/denisinvader/mounted-and-beforedestroy-hooks-in-vuejs-functional-components-7bi</guid>
      <description>&lt;p&gt;When you using Vue.js &lt;a href="https://vuejs.org/v2/guide/render-function.html#Functional-Components" rel="noopener noreferrer"&gt;functional components&lt;/a&gt; you have nothing except render function and it's context with some parameters.&lt;/p&gt;

&lt;p&gt;I always prefer to use functional component instead of a stateful component in my shared components library at work and it works fine when I don't need state. But sometimes I need &lt;code&gt;mounted&lt;/code&gt; and &lt;code&gt;beforeDestroy&lt;/code&gt; hooks in a stateless component.&lt;/p&gt;

&lt;h2&gt;
  
  
  The problem
&lt;/h2&gt;

&lt;p&gt;Let's look at the example. We need a simple modal component that renders some overlay and block with passed children. Something like this:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight jsx"&gt;&lt;code&gt;&lt;span class="k"&gt;export&lt;/span&gt; &lt;span class="k"&gt;default&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="na"&gt;functional&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="nf"&gt;render &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;h&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;context&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="k"&gt;return &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
      &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;div&lt;/span&gt; &lt;span class="na"&gt;class&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"modal"&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
        &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;div&lt;/span&gt; &lt;span class="na"&gt;class&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"modal__overlay"&lt;/span&gt; &lt;span class="p"&gt;/&amp;gt;&lt;/span&gt;
        &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;div&lt;/span&gt; &lt;span class="na"&gt;class&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"modal__content"&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;context&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;children&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;div&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
      &lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;div&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
    &lt;span class="p"&gt;);&lt;/span&gt;
  &lt;span class="p"&gt;},&lt;/span&gt;
&lt;span class="p"&gt;};&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;I didn't provide any styles but it should look like &lt;a href="https://getbootstrap.com/docs/4.0/components/modal/#live-demo" rel="noopener noreferrer"&gt;bootstrap modal&lt;/a&gt;. Now if the window has y scroll opened modal will be moving with page scroll. To create better UX we should disable scroll when modal is opened and enable it again when modal is closed. When using usual components you can do it in &lt;code&gt;mounted&lt;/code&gt; and &lt;code&gt;befoDestroy&lt;/code&gt; hooks:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight javascript"&gt;&lt;code&gt;&lt;span class="k"&gt;export&lt;/span&gt; &lt;span class="k"&gt;default&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="c1"&gt;// ...&lt;/span&gt;
  &lt;span class="nf"&gt;mounted &lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="nb"&gt;document&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;body&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;style&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;overflow&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;hidden&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
  &lt;span class="p"&gt;},&lt;/span&gt;
  &lt;span class="nf"&gt;beforeDestroy &lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="nb"&gt;document&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;body&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;style&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;overflow&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="kc"&gt;null&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
  &lt;span class="p"&gt;},&lt;/span&gt;
  &lt;span class="c1"&gt;// ...&lt;/span&gt;
&lt;span class="p"&gt;};&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;But how to implement this logic without hooks? The answer is: using &lt;code&gt;&amp;lt;transition&amp;gt;&lt;/code&gt; component with &lt;code&gt;appear&lt;/code&gt; prop! &lt;/p&gt;

&lt;h2&gt;
  
  
  The solution
&lt;/h2&gt;

&lt;p&gt;&lt;code&gt;&amp;lt;transition&amp;gt;&lt;/code&gt; component has its own &lt;a href="https://vuejs.org/v2/guide/transitions.html#JavaScript-Hooks" rel="noopener noreferrer"&gt;hooks&lt;/a&gt; for entering and leaving, so we can just wrap all our component in it and define hooks. The &lt;code&gt;appear&lt;/code&gt; prop guarantees that our "mounted" hook will be fired when component mounts.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight jsx"&gt;&lt;code&gt;&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;mounted&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="nb"&gt;document&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;body&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;style&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;overflow&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;hidden&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
&lt;span class="p"&gt;};&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;beforeDestroy&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="nb"&gt;document&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;body&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;style&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;overflow&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="kc"&gt;null&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
&lt;span class="p"&gt;};&lt;/span&gt;

&lt;span class="k"&gt;export&lt;/span&gt; &lt;span class="k"&gt;default&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="na"&gt;functional&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="nf"&gt;render &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;h&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;context&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="k"&gt;return &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
      &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;transition&lt;/span&gt;
        &lt;span class="na"&gt;appear&lt;/span&gt;
        &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"fade"&lt;/span&gt;
        &lt;span class="na"&gt;onAfterEnter&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;mounted&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
        &lt;span class="na"&gt;onBeforeLeave&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;beforeDestroy&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
      &lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
        &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;div&lt;/span&gt; &lt;span class="na"&gt;class&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"modal"&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
          &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;div&lt;/span&gt; &lt;span class="na"&gt;class&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"modal__overlay"&lt;/span&gt; &lt;span class="p"&gt;/&amp;gt;&lt;/span&gt;
          &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;div&lt;/span&gt; &lt;span class="na"&gt;class&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"modal__content"&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;context&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;children&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;div&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
        &lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;div&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
      &lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;transition&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
    &lt;span class="p"&gt;);&lt;/span&gt;
  &lt;span class="p"&gt;},&lt;/span&gt;
&lt;span class="p"&gt;};&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;That's it! Now we have some hooks in a functional component. &lt;/p&gt;

&lt;p&gt;You can also improve your UI by implementing transition animations.&lt;/p&gt;

&lt;blockquote&gt;
&lt;p&gt;Photo by Suad Kamardeen on Unsplash&lt;/p&gt;
&lt;/blockquote&gt;

</description>
      <category>javascript</category>
      <category>vue</category>
      <category>hack</category>
    </item>
    <item>
      <title>Creating an interactive map with D3 and Vue</title>
      <dc:creator>Mikhail Panichev</dc:creator>
      <pubDate>Sun, 07 Oct 2018 00:13:52 +0000</pubDate>
      <link>https://dev.to/denisinvader/creating-an-interactive-map-with-d3-and-vue-4158</link>
      <guid>https://dev.to/denisinvader/creating-an-interactive-map-with-d3-and-vue-4158</guid>
      <description>&lt;p&gt;&lt;a href="https://github.com/denisinvader/vue-d3-map" rel="noopener noreferrer"&gt;Source code&lt;/a&gt; | &lt;a href="https://denisinvader.github.io/vue-d3-map/" rel="noopener noreferrer"&gt;Live preview&lt;/a&gt;&lt;/p&gt;

&lt;h2&gt;
  
  
  Why do I need it at all
&lt;/h2&gt;

&lt;p&gt;There are many ways to include a map in your website or application: Google Maps, Mapbox, Leaflet etc. It's simple. Some services allows you to do it in just few clicks.&lt;/p&gt;

&lt;p&gt;But it's getting bad when you need to customise the design, display some dataset or do whatever you want. Moreover, in Vue or React you can't use JSX and have to use imperative abstract javascript API (but I use Vue because I'm very excited by templates and reactivity). &lt;/p&gt;

&lt;p&gt;Also some libraries are not free for private projects.&lt;/p&gt;

&lt;p&gt;So once again I had to display some data on map I decided: I want full control in my code and I will create my own map with blackjack and hookers.&lt;/p&gt;

&lt;h2&gt;
  
  
  Step 1: Create a static map.
&lt;/h2&gt;

&lt;p&gt;Let's start with simple vue-cli 3 app with Babel and sass.&lt;/p&gt;

&lt;p&gt;We need D3 and &lt;a href="https://github.com/d3/d3-tile" rel="noopener noreferrer"&gt;d3-tile&lt;/a&gt; (it doesn't included in d3 npm package) for rendering map tiles.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight shell"&gt;&lt;code&gt;yarn add d3 d3-tile
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Actually we don't need whole d3 code. For a simple map we only need d3-geo for map projection and d3-tile for generating tiles, so we will include only these packages.&lt;/p&gt;

&lt;p&gt;Next we should define some settings like scale, width, height and initial coordinates. Usually I make all my charts responsive to it container by calculating element's size on mount.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight vue"&gt;&lt;code&gt;&lt;span class="nt"&gt;&amp;lt;&lt;/span&gt;&lt;span class="k"&gt;script&lt;/span&gt;&lt;span class="nt"&gt;&amp;gt;&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;d3&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="p"&gt;...&lt;/span&gt;&lt;span class="nf"&gt;require&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;d3-geo&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt;
  &lt;span class="p"&gt;...&lt;/span&gt;&lt;span class="nf"&gt;require&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;d3-tile&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt;
&lt;span class="p"&gt;};&lt;/span&gt;

&lt;span class="k"&gt;export&lt;/span&gt; &lt;span class="k"&gt;default&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="na"&gt;props&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="na"&gt;center&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="na"&gt;type&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;Array&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
      &lt;span class="na"&gt;default&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="mf"&gt;33.561041&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="o"&gt;-&lt;/span&gt;&lt;span class="mf"&gt;7.584838&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;
    &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="na"&gt;scale&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="na"&gt;type&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="nb"&gt;Number&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nb"&gt;String&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;
      &lt;span class="na"&gt;default&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="mi"&gt;1&lt;/span&gt; &lt;span class="o"&gt;&amp;lt;&amp;lt;&lt;/span&gt; &lt;span class="mi"&gt;20&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="p"&gt;},&lt;/span&gt;
  &lt;span class="p"&gt;},&lt;/span&gt;
  &lt;span class="nf"&gt;data &lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="na"&gt;width&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="mi"&gt;0&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
      &lt;span class="na"&gt;height&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="mi"&gt;0&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="p"&gt;};&lt;/span&gt;
  &lt;span class="p"&gt;},&lt;/span&gt;
  &lt;span class="nf"&gt;mounted &lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;rect&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;$el&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;getBoundingClientRect&lt;/span&gt;&lt;span class="p"&gt;();&lt;/span&gt;

    &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;width&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;rect&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;width&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
    &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;height&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;rect&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;height&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
  &lt;span class="p"&gt;},&lt;/span&gt;
  &lt;span class="nf"&gt;render &lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;width&lt;/span&gt; &lt;span class="o"&gt;&amp;lt;=&lt;/span&gt; &lt;span class="mi"&gt;0&lt;/span&gt; &lt;span class="o"&gt;||&lt;/span&gt; &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;height&lt;/span&gt; &lt;span class="o"&gt;&amp;lt;=&lt;/span&gt; &lt;span class="mi"&gt;0&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="c1"&gt;// the dummy for calculating element size&lt;/span&gt;
      &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="o"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nx"&gt;div&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="s2"&gt;map&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt; &lt;span class="o"&gt;/&amp;gt;&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
    &lt;span class="p"&gt;}&lt;/span&gt;

    &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;
      &lt;span class="o"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nx"&gt;div&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="s2"&gt;map&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="o"&gt;&amp;gt;&lt;/span&gt;&lt;span class="nx"&gt;our&lt;/span&gt; &lt;span class="nx"&gt;map&lt;/span&gt; &lt;span class="nx"&gt;will&lt;/span&gt; &lt;span class="nx"&gt;be&lt;/span&gt; &lt;span class="nx"&gt;here&lt;/span&gt;&lt;span class="o"&gt;&amp;lt;&lt;/span&gt;&lt;span class="sr"&gt;/div&lt;/span&gt;&lt;span class="err"&gt;&amp;gt;
&lt;/span&gt;    &lt;span class="p"&gt;);&lt;/span&gt;
  &lt;span class="p"&gt;},&lt;/span&gt;
&lt;span class="p"&gt;};&lt;/span&gt;
&lt;span class="nt"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="k"&gt;script&lt;/span&gt;&lt;span class="nt"&gt;&amp;gt;&lt;/span&gt;

&lt;span class="nt"&gt;&amp;lt;&lt;/span&gt;&lt;span class="k"&gt;style&lt;/span&gt; &lt;span class="na"&gt;lang=&lt;/span&gt;&lt;span class="s"&gt;"scss"&lt;/span&gt; &lt;span class="na"&gt;scoped&lt;/span&gt;&lt;span class="nt"&gt;&amp;gt;&lt;/span&gt;
&lt;span class="nc"&gt;.map&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="nl"&gt;width&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="m"&gt;100%&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
  &lt;span class="nl"&gt;height&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="m"&gt;100%&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;
&lt;span class="nt"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="k"&gt;style&lt;/span&gt;&lt;span class="nt"&gt;&amp;gt;&lt;/span&gt;

&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Now define the projection and tiles generator.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight javascript"&gt;&lt;code&gt;&lt;span class="k"&gt;export&lt;/span&gt; &lt;span class="k"&gt;default&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="c1"&gt;// ... &lt;/span&gt;
  &lt;span class="na"&gt;computed&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="nf"&gt;projection &lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="nx"&gt;d3&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;geoMercator&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
        &lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;scale&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="o"&gt;+&lt;/span&gt;&lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;scale&lt;/span&gt; &lt;span class="o"&gt;/&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;2&lt;/span&gt; &lt;span class="o"&gt;*&lt;/span&gt; &lt;span class="nb"&gt;Math&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;PI&lt;/span&gt;&lt;span class="p"&gt;))&lt;/span&gt;
        &lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;translate&lt;/span&gt;&lt;span class="p"&gt;([&lt;/span&gt;&lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;width&lt;/span&gt; &lt;span class="o"&gt;/&lt;/span&gt; &lt;span class="mi"&gt;2&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;height&lt;/span&gt; &lt;span class="o"&gt;/&lt;/span&gt; &lt;span class="mi"&gt;2&lt;/span&gt;&lt;span class="p"&gt;])&lt;/span&gt;
        &lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;center&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;center&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
      &lt;span class="p"&gt;;&lt;/span&gt;
    &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="nf"&gt;tiles &lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="nx"&gt;d3&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;tile&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
        &lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;size&lt;/span&gt;&lt;span class="p"&gt;([&lt;/span&gt;&lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;width&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;height&lt;/span&gt;&lt;span class="p"&gt;])&lt;/span&gt;
        &lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;scale&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="o"&gt;+&lt;/span&gt;&lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;scale&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
        &lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;translate&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;projection&lt;/span&gt;&lt;span class="p"&gt;([&lt;/span&gt;&lt;span class="mi"&gt;0&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="mi"&gt;0&lt;/span&gt;&lt;span class="p"&gt;]))()&lt;/span&gt;
      &lt;span class="p"&gt;;&lt;/span&gt;
    &lt;span class="p"&gt;},&lt;/span&gt;
  &lt;span class="p"&gt;},&lt;/span&gt;
  &lt;span class="c1"&gt;// ...&lt;/span&gt;
&lt;span class="p"&gt;};&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;I always define d3 helper functions as computed properties, so when some params are changing Vue recalculates them and updates our component.&lt;/p&gt;

&lt;p&gt;Now we have everything needed for displaying the map and we just render generated tiles:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight javascript"&gt;&lt;code&gt;&lt;span class="k"&gt;export&lt;/span&gt; &lt;span class="k"&gt;default&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="nf"&gt;render &lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="k"&gt;if &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;width&lt;/span&gt; &lt;span class="o"&gt;&amp;lt;=&lt;/span&gt; &lt;span class="mi"&gt;0&lt;/span&gt; &lt;span class="o"&gt;||&lt;/span&gt; &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;height&lt;/span&gt; &lt;span class="o"&gt;&amp;lt;=&lt;/span&gt; &lt;span class="mi"&gt;0&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="o"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nx"&gt;div&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="s2"&gt;map&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt; &lt;span class="o"&gt;/&amp;gt;&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
    &lt;span class="p"&gt;}&lt;/span&gt;

    &lt;span class="k"&gt;return &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
      &lt;span class="o"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nx"&gt;div&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="s2"&gt;map&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="o"&gt;&amp;gt;&lt;/span&gt;
        &lt;span class="o"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nx"&gt;svg&lt;/span&gt; &lt;span class="nx"&gt;viewBox&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="s2"&gt;`0 0 &lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;width&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt; &lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;height&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;`&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="o"&gt;&amp;gt;&lt;/span&gt;
          &lt;span class="o"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nx"&gt;g&lt;/span&gt;&lt;span class="o"&gt;&amp;gt;&lt;/span&gt;
            &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;tiles&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;map&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;t&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;
              &lt;span class="o"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nx"&gt;image&lt;/span&gt;
                &lt;span class="nx"&gt;key&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="s2"&gt;`&lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="nx"&gt;t&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;x&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;_&lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="nx"&gt;t&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;y&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;_&lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="nx"&gt;t&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;`&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;
                &lt;span class="kd"&gt;class&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="s2"&gt;map__tile&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;
                &lt;span class="nx"&gt;xlinkHref&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="s2"&gt;`https://a.tile.openstreetmap.org/&lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="nx"&gt;t&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;z&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;/&lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="nx"&gt;t&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;x&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;/&lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="nx"&gt;t&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;y&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;.png `&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;
                &lt;span class="nx"&gt;x&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="p"&gt;{(&lt;/span&gt;&lt;span class="nx"&gt;t&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;x&lt;/span&gt; &lt;span class="o"&gt;+&lt;/span&gt; &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;tiles&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;translate&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="mi"&gt;0&lt;/span&gt;&lt;span class="p"&gt;])&lt;/span&gt; &lt;span class="o"&gt;*&lt;/span&gt; &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;tiles&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;scale&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;
                &lt;span class="nx"&gt;y&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="p"&gt;{(&lt;/span&gt;&lt;span class="nx"&gt;t&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;y&lt;/span&gt; &lt;span class="o"&gt;+&lt;/span&gt; &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;tiles&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;translate&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="mi"&gt;1&lt;/span&gt;&lt;span class="p"&gt;])&lt;/span&gt; &lt;span class="o"&gt;*&lt;/span&gt; &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;tiles&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;scale&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;
                &lt;span class="nx"&gt;width&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;tiles&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;scale&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;
                &lt;span class="nx"&gt;height&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;tiles&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;scale&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;
              &lt;span class="sr"&gt;/&lt;/span&gt;&lt;span class="err"&gt;&amp;gt;
&lt;/span&gt;            &lt;span class="p"&gt;))}&lt;/span&gt;
          &lt;span class="o"&gt;&amp;lt;&lt;/span&gt;&lt;span class="sr"&gt;/g&lt;/span&gt;&lt;span class="err"&gt;&amp;gt;
&lt;/span&gt;        &lt;span class="o"&gt;&amp;lt;&lt;/span&gt;&lt;span class="sr"&gt;/svg&lt;/span&gt;&lt;span class="err"&gt;&amp;gt;
&lt;/span&gt;      &lt;span class="o"&gt;&amp;lt;&lt;/span&gt;&lt;span class="sr"&gt;/div&lt;/span&gt;&lt;span class="err"&gt;&amp;gt;
&lt;/span&gt;    &lt;span class="p"&gt;);&lt;/span&gt;
  &lt;span class="p"&gt;},&lt;/span&gt;
&lt;span class="p"&gt;};&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Here we go through tiles generated by d3-tile and request images from tile server. &lt;/p&gt;

&lt;p&gt;You can find other servers &lt;a href="https://wiki.openstreetmap.org/wiki/Tile_servers" rel="noopener noreferrer"&gt;here&lt;/a&gt; or you can even host your &lt;a href="https://openmaptiles.org" rel="noopener noreferrer"&gt;own tile server&lt;/a&gt; with custom styles. &lt;/p&gt;

&lt;p&gt;Don't forget to add a copyright.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight html"&gt;&lt;code&gt;&lt;span class="nt"&gt;&amp;lt;div&lt;/span&gt; &lt;span class="na"&gt;class=&lt;/span&gt;&lt;span class="s"&gt;"map__copyright"&lt;/span&gt;&lt;span class="nt"&gt;&amp;gt;&lt;/span&gt;
  ©&lt;span class="ni"&gt;&amp;amp;nbsp;&lt;/span&gt;
  &lt;span class="nt"&gt;&amp;lt;a&lt;/span&gt;
    &lt;span class="na"&gt;href=&lt;/span&gt;&lt;span class="s"&gt;"https://www.openstreetmap.org/copyright"&lt;/span&gt;
    &lt;span class="na"&gt;target=&lt;/span&gt;&lt;span class="s"&gt;"_blank"&lt;/span&gt;
  &lt;span class="nt"&gt;&amp;gt;&lt;/span&gt;OpenStreetMap&lt;span class="ni"&gt;&amp;amp;nbsp;&lt;/span&gt;&lt;span class="nt"&gt;&amp;lt;/a&amp;gt;&lt;/span&gt;
  contributors
&lt;span class="nt"&gt;&amp;lt;/div&amp;gt;&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;





&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight scss"&gt;&lt;code&gt;&lt;span class="nc"&gt;.map&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="c1"&gt;// ...&lt;/span&gt;
  &lt;span class="nl"&gt;position&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;relative&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
  &lt;span class="nl"&gt;font-family&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;Arial&lt;/span&gt;&lt;span class="o"&gt;,&lt;/span&gt; &lt;span class="n"&gt;sans&lt;/span&gt;&lt;span class="o"&gt;,&lt;/span&gt; &lt;span class="nb"&gt;sans-serif&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

  &lt;span class="k"&gt;&amp;amp;&lt;/span&gt;&lt;span class="nt"&gt;__copyright&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="nl"&gt;position&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;absolute&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
    &lt;span class="nl"&gt;bottom&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="m"&gt;8px&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
    &lt;span class="nl"&gt;right&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="m"&gt;8px&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
    &lt;span class="nl"&gt;padding&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="m"&gt;2px&lt;/span&gt; &lt;span class="m"&gt;4px&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
    &lt;span class="nl"&gt;background-color&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nf"&gt;rgba&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mh"&gt;#ffffff&lt;/span&gt;&lt;span class="o"&gt;,&lt;/span&gt; &lt;span class="mi"&gt;.6&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;
    &lt;span class="nl"&gt;font-size&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="m"&gt;14px&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Now we have the static map of Casablanca. Not very exciting yet.&lt;/p&gt;

&lt;p&gt;&lt;a href="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Farticles%2Ffbzxmtz2m2m4ua7wahpf.png" class="article-body-image-wrapper"&gt;&lt;img src="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Farticles%2Ffbzxmtz2m2m4ua7wahpf.png" alt="Casablanca map" width="800" height="423"&gt;&lt;/a&gt;&lt;/p&gt;

&lt;h2&gt;
  
  
  Step 2: Add map controls.
&lt;/h2&gt;

&lt;p&gt;The most exciting thing for me is how Vue makes simpler the way to create an interactive map. We just update projection params and map updates. It was like easy peasy magic at first time!&lt;/p&gt;

&lt;p&gt;We'll make zoom buttons and position control by dragging the map. &lt;/p&gt;

&lt;p&gt;Let's start with dragging. We need to define projection translate props in component data and some mouse event listeners on svg element (or you can listen them on tiles group).&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight vue"&gt;&lt;code&gt;&lt;span class="nt"&gt;&amp;lt;&lt;/span&gt;&lt;span class="k"&gt;script&lt;/span&gt;&lt;span class="nt"&gt;&amp;gt;&lt;/span&gt;
&lt;span class="c1"&gt;// ...&lt;/span&gt;

&lt;span class="k"&gt;export&lt;/span&gt; &lt;span class="k"&gt;default&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="c1"&gt;// ...&lt;/span&gt;
  &lt;span class="nf"&gt;data &lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="c1"&gt;// ...&lt;/span&gt;
      &lt;span class="na"&gt;translateX&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="mi"&gt;0&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
      &lt;span class="na"&gt;translateY&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="mi"&gt;0&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;

      &lt;span class="na"&gt;touchStarted&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;false&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
      &lt;span class="na"&gt;touchLastX&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="mi"&gt;0&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
      &lt;span class="na"&gt;touchLastY&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="mi"&gt;0&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="p"&gt;};&lt;/span&gt;
  &lt;span class="p"&gt;},&lt;/span&gt;
  &lt;span class="na"&gt;computed&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="nf"&gt;projection &lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="nx"&gt;d3&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;geoMercator&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
        &lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;scale&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="o"&gt;+&lt;/span&gt;&lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;scale&lt;/span&gt; &lt;span class="o"&gt;/&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;2&lt;/span&gt; &lt;span class="o"&gt;*&lt;/span&gt; &lt;span class="nb"&gt;Math&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;PI&lt;/span&gt;&lt;span class="p"&gt;))&lt;/span&gt;
        &lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;translate&lt;/span&gt;&lt;span class="p"&gt;([&lt;/span&gt;&lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;translateX&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;translateY&lt;/span&gt;&lt;span class="p"&gt;])&lt;/span&gt;
        &lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;center&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;center&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
      &lt;span class="p"&gt;;&lt;/span&gt;
    &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="c1"&gt;// ...&lt;/span&gt;
  &lt;span class="p"&gt;},&lt;/span&gt;
  &lt;span class="nf"&gt;mounted &lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="c1"&gt;// ...&lt;/span&gt;
    &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;translateX&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;width&lt;/span&gt; &lt;span class="o"&gt;/&lt;/span&gt; &lt;span class="mi"&gt;2&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
    &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;translateY&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;height&lt;/span&gt; &lt;span class="o"&gt;/&lt;/span&gt; &lt;span class="mi"&gt;2&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
  &lt;span class="p"&gt;},&lt;/span&gt;
  &lt;span class="na"&gt;methods&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="nf"&gt;onTouchStart &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;e&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;touchStarted&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

      &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;touchLastX&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;e&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;clientX&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
      &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;touchLastY&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;e&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;clientY&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
    &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="nf"&gt;onTouchEnd &lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;touchStarted&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="kc"&gt;false&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
    &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="nf"&gt;onTouchMove &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;e&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="k"&gt;if &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;touchStarted&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;translateX&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;translateX&lt;/span&gt; &lt;span class="o"&gt;+&lt;/span&gt; &lt;span class="nx"&gt;e&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;clientX&lt;/span&gt; &lt;span class="o"&gt;-&lt;/span&gt; &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;touchLastX&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
        &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;translateY&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;translateY&lt;/span&gt; &lt;span class="o"&gt;+&lt;/span&gt; &lt;span class="nx"&gt;e&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;clientY&lt;/span&gt; &lt;span class="o"&gt;-&lt;/span&gt; &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;touchLastY&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

        &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;touchLastX&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;e&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;clientX&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
        &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;touchLastY&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;e&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;clientY&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
      &lt;span class="p"&gt;}&lt;/span&gt;
    &lt;span class="p"&gt;},&lt;/span&gt;
  &lt;span class="p"&gt;},&lt;/span&gt;
  &lt;span class="nf"&gt;render &lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="c1"&gt;// ...&lt;/span&gt;
    &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;
      &lt;span class="o"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nx"&gt;div&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="s2"&gt;map&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="o"&gt;&amp;gt;&lt;/span&gt;
        &lt;span class="o"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nx"&gt;svg&lt;/span&gt;
          &lt;span class="nx"&gt;viewBox&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="s2"&gt;`0 0 &lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;width&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt; &lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;height&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;`&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;
          &lt;span class="nx"&gt;onMousedown&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;onTouchStart&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;
          &lt;span class="nx"&gt;onMousemove&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;onTouchMove&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;
          &lt;span class="nx"&gt;onMouseup&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;onTouchEnd&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;
          &lt;span class="nx"&gt;onMouseleave&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;onTouchEnd&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;
        &lt;span class="o"&gt;&amp;gt;&lt;/span&gt;
          &lt;span class="c1"&gt;// ...&lt;/span&gt;
        &lt;span class="o"&gt;&amp;lt;&lt;/span&gt;&lt;span class="sr"&gt;/svg&lt;/span&gt;&lt;span class="err"&gt;&amp;gt;
&lt;/span&gt;        &lt;span class="c1"&gt;// ...&lt;/span&gt;
      &lt;span class="o"&gt;&amp;lt;&lt;/span&gt;&lt;span class="sr"&gt;/div&lt;/span&gt;&lt;span class="err"&gt;&amp;gt;
&lt;/span&gt;    &lt;span class="p"&gt;);&lt;/span&gt;
  &lt;span class="p"&gt;},&lt;/span&gt;
&lt;span class="p"&gt;};&lt;/span&gt;
&lt;span class="nt"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="k"&gt;script&lt;/span&gt;&lt;span class="nt"&gt;&amp;gt;&lt;/span&gt;

&lt;span class="nt"&gt;&amp;lt;&lt;/span&gt;&lt;span class="k"&gt;style&lt;/span&gt; &lt;span class="na"&gt;lang=&lt;/span&gt;&lt;span class="s"&gt;"scss"&lt;/span&gt; &lt;span class="na"&gt;scoped&lt;/span&gt;&lt;span class="nt"&gt;&amp;gt;&lt;/span&gt;
&lt;span class="nc"&gt;.map&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="c1"&gt;// ...&lt;/span&gt;

  &lt;span class="k"&gt;&amp;amp;&lt;/span&gt;&lt;span class="nt"&gt;__tile&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="c1"&gt;// reset pointer events on images to prevent image dragging in Firefox&lt;/span&gt;
    &lt;span class="nl"&gt;pointer-events&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;none&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt;
  &lt;span class="c1"&gt;// ...&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;
&lt;span class="nt"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="k"&gt;style&lt;/span&gt;&lt;span class="nt"&gt;&amp;gt;&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Wow! We just update translate values and new tiles are loading so we can explore the world. But it isn't very comfortable to do without a zoom control, so let's implement it. &lt;/p&gt;

&lt;p&gt;We need to move &lt;code&gt;scale&lt;/code&gt; prop in component's data, add &lt;code&gt;zoom&lt;/code&gt; property and render zoom buttons. &lt;/p&gt;

&lt;p&gt;In my experience minimal and maximum tile's zoom level are 10 and 27 (honestly I'm not very sure that this correct for all tile providers).&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight vue"&gt;&lt;code&gt;&lt;span class="nt"&gt;&amp;lt;&lt;/span&gt;&lt;span class="k"&gt;script&lt;/span&gt;&lt;span class="nt"&gt;&amp;gt;&lt;/span&gt;
&lt;span class="c1"&gt;// ...&lt;/span&gt;

&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;MIN_ZOOM&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="mi"&gt;10&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;MAX_ZOOM&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="mi"&gt;27&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

&lt;span class="k"&gt;export&lt;/span&gt; &lt;span class="k"&gt;default&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="na"&gt;props&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="na"&gt;center&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="na"&gt;type&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;Array&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
      &lt;span class="na"&gt;default&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="o"&gt;-&lt;/span&gt;&lt;span class="mf"&gt;7.584838&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="mf"&gt;33.561041&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;
    &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="na"&gt;initialZoom&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="na"&gt;type&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="nb"&gt;Number&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nb"&gt;String&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;
      &lt;span class="na"&gt;default&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="mi"&gt;20&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="p"&gt;},&lt;/span&gt;
  &lt;span class="p"&gt;},&lt;/span&gt;
  &lt;span class="nf"&gt;data &lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="c1"&gt;// ...&lt;/span&gt;
      &lt;span class="na"&gt;zoom&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="o"&gt;+&lt;/span&gt;&lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;initialZoom&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
      &lt;span class="na"&gt;scale&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="mi"&gt;1&lt;/span&gt; &lt;span class="o"&gt;&amp;lt;&amp;lt;&lt;/span&gt; &lt;span class="o"&gt;+&lt;/span&gt;&lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;initialZoom&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="p"&gt;};&lt;/span&gt;
  &lt;span class="p"&gt;},&lt;/span&gt;
  &lt;span class="c1"&gt;// ...&lt;/span&gt;
  &lt;span class="na"&gt;watch&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="nf"&gt;zoom &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;zoom&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;prevZoom&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;k&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;zoom&lt;/span&gt; &lt;span class="o"&gt;-&lt;/span&gt; &lt;span class="nx"&gt;prevZoom&lt;/span&gt; &lt;span class="o"&gt;&amp;gt;&lt;/span&gt; &lt;span class="mi"&gt;0&lt;/span&gt; &lt;span class="p"&gt;?&lt;/span&gt; &lt;span class="mi"&gt;2&lt;/span&gt; &lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="mi"&gt;5&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

      &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;scale&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="mi"&gt;1&lt;/span&gt; &lt;span class="o"&gt;&amp;lt;&amp;lt;&lt;/span&gt; &lt;span class="nx"&gt;zoom&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
      &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;translateY&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;height&lt;/span&gt; &lt;span class="o"&gt;/&lt;/span&gt; &lt;span class="mi"&gt;2&lt;/span&gt; &lt;span class="o"&gt;-&lt;/span&gt; &lt;span class="nx"&gt;k&lt;/span&gt; &lt;span class="o"&gt;*&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;height&lt;/span&gt; &lt;span class="o"&gt;/&lt;/span&gt; &lt;span class="mi"&gt;2&lt;/span&gt; &lt;span class="o"&gt;-&lt;/span&gt; &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;translateY&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;
      &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;translateX&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;width&lt;/span&gt; &lt;span class="o"&gt;/&lt;/span&gt; &lt;span class="mi"&gt;2&lt;/span&gt; &lt;span class="o"&gt;-&lt;/span&gt; &lt;span class="nx"&gt;k&lt;/span&gt; &lt;span class="o"&gt;*&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;width&lt;/span&gt; &lt;span class="o"&gt;/&lt;/span&gt; &lt;span class="mi"&gt;2&lt;/span&gt; &lt;span class="o"&gt;-&lt;/span&gt; &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;translateX&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;
    &lt;span class="p"&gt;},&lt;/span&gt;
  &lt;span class="p"&gt;},&lt;/span&gt;
  &lt;span class="c1"&gt;// ...&lt;/span&gt;
  &lt;span class="na"&gt;methods&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="c1"&gt;// ...&lt;/span&gt;
    &lt;span class="nf"&gt;zoomIn &lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;zoom&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nb"&gt;Math&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;min&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;zoom&lt;/span&gt; &lt;span class="o"&gt;+&lt;/span&gt; &lt;span class="mi"&gt;1&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;MAX_ZOOM&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;
    &lt;span class="p"&gt;},&lt;/span&gt;
    &lt;span class="nf"&gt;zoomOut &lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;zoom&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nb"&gt;Math&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;max&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;zoom&lt;/span&gt; &lt;span class="o"&gt;-&lt;/span&gt; &lt;span class="mi"&gt;1&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;MIN_ZOOM&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;
    &lt;span class="p"&gt;},&lt;/span&gt;
  &lt;span class="p"&gt;},&lt;/span&gt;
  &lt;span class="nf"&gt;render &lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="c1"&gt;// ...&lt;/span&gt;
    &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;
      &lt;span class="o"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nx"&gt;div&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="s2"&gt;map&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="o"&gt;&amp;gt;&lt;/span&gt;
        &lt;span class="o"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nx"&gt;div&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="s2"&gt;map__controls&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="o"&gt;&amp;gt;&lt;/span&gt;
          &lt;span class="o"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nx"&gt;button&lt;/span&gt;
            &lt;span class="kd"&gt;class&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="s2"&gt;map__button&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;
            &lt;span class="nx"&gt;disabled&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;zoom&lt;/span&gt; &lt;span class="o"&gt;&amp;gt;=&lt;/span&gt; &lt;span class="nx"&gt;MAX_ZOOM&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;
            &lt;span class="nx"&gt;onClick&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;zoomIn&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;
          &lt;span class="o"&gt;&amp;gt;+&amp;lt;&lt;/span&gt;&lt;span class="sr"&gt;/button&lt;/span&gt;&lt;span class="err"&gt;&amp;gt;
&lt;/span&gt;          &lt;span class="o"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nx"&gt;button&lt;/span&gt;
            &lt;span class="kd"&gt;class&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="s2"&gt;map__button&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;
            &lt;span class="nx"&gt;disabled&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;zoom&lt;/span&gt; &lt;span class="o"&gt;&amp;lt;=&lt;/span&gt; &lt;span class="nx"&gt;MIN_ZOOM&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;
            &lt;span class="nx"&gt;onClick&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;zoomOut&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;
          &lt;span class="o"&gt;&amp;gt;-&amp;lt;&lt;/span&gt;&lt;span class="sr"&gt;/button&lt;/span&gt;&lt;span class="err"&gt;&amp;gt;
&lt;/span&gt;        &lt;span class="o"&gt;&amp;lt;&lt;/span&gt;&lt;span class="sr"&gt;/div&lt;/span&gt;&lt;span class="err"&gt;&amp;gt;
&lt;/span&gt;        &lt;span class="c1"&gt;//...&lt;/span&gt;
      &lt;span class="o"&gt;&amp;lt;&lt;/span&gt;&lt;span class="sr"&gt;/div&lt;/span&gt;&lt;span class="err"&gt;&amp;gt;
&lt;/span&gt;    &lt;span class="p"&gt;);&lt;/span&gt;
  &lt;span class="p"&gt;},&lt;/span&gt;
&lt;span class="p"&gt;};&lt;/span&gt;
&lt;span class="nt"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="k"&gt;script&lt;/span&gt;&lt;span class="nt"&gt;&amp;gt;&lt;/span&gt;

&lt;span class="nt"&gt;&amp;lt;&lt;/span&gt;&lt;span class="k"&gt;style&lt;/span&gt; &lt;span class="na"&gt;lang=&lt;/span&gt;&lt;span class="s"&gt;"scss"&lt;/span&gt; &lt;span class="na"&gt;scoped&lt;/span&gt;&lt;span class="nt"&gt;&amp;gt;&lt;/span&gt;
&lt;span class="nc"&gt;.map&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="c1"&gt;// ...&lt;/span&gt;
  &lt;span class="k"&gt;&amp;amp;&lt;/span&gt;&lt;span class="nt"&gt;__controls&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="nl"&gt;position&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;absolute&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
    &lt;span class="nl"&gt;left&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="m"&gt;16px&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
    &lt;span class="nl"&gt;top&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="m"&gt;16px&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
    &lt;span class="nl"&gt;display&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;flex&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
    &lt;span class="nl"&gt;flex-direction&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;column&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
    &lt;span class="nl"&gt;justify-content&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;space-between&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
    &lt;span class="nl"&gt;height&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="m"&gt;56px&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt;
  &lt;span class="k"&gt;&amp;amp;&lt;/span&gt;&lt;span class="nt"&gt;__button&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="nl"&gt;border&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="m"&gt;0&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
    &lt;span class="nl"&gt;padding&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="m"&gt;0&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
    &lt;span class="nl"&gt;width&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="m"&gt;24px&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
    &lt;span class="nl"&gt;height&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="m"&gt;24px&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
    &lt;span class="nl"&gt;line-height&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="m"&gt;24px&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
    &lt;span class="nl"&gt;border-radius&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="m"&gt;50%&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
    &lt;span class="nl"&gt;font-size&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="m"&gt;18px&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
    &lt;span class="nl"&gt;background-color&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="mh"&gt;#ffffff&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
    &lt;span class="nl"&gt;color&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="mh"&gt;#343434&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
    &lt;span class="nl"&gt;box-shadow&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="m"&gt;0&lt;/span&gt; &lt;span class="m"&gt;1px&lt;/span&gt; &lt;span class="m"&gt;4px&lt;/span&gt; &lt;span class="nf"&gt;rgba&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="m"&gt;0&lt;/span&gt;&lt;span class="o"&gt;,&lt;/span&gt; &lt;span class="m"&gt;0&lt;/span&gt;&lt;span class="o"&gt;,&lt;/span&gt; &lt;span class="m"&gt;0&lt;/span&gt;&lt;span class="o"&gt;,&lt;/span&gt; &lt;span class="mi"&gt;.4&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;

    &lt;span class="k"&gt;&amp;amp;&lt;/span&gt;&lt;span class="nd"&gt;:hover&lt;/span&gt;&lt;span class="o"&gt;,&lt;/span&gt;
    &lt;span class="k"&gt;&amp;amp;&lt;/span&gt;&lt;span class="nd"&gt;:focus&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="nl"&gt;background-color&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="mh"&gt;#eeeeee&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
    &lt;span class="p"&gt;}&lt;/span&gt;

    &lt;span class="k"&gt;&amp;amp;&lt;/span&gt;&lt;span class="nd"&gt;:disabled&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="nl"&gt;background-color&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nf"&gt;rgba&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mh"&gt;#eeeeee&lt;/span&gt;&lt;span class="o"&gt;,&lt;/span&gt; &lt;span class="mi"&gt;.4&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;
    &lt;span class="p"&gt;}&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt;
  &lt;span class="c1"&gt;// ...&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;
&lt;span class="nt"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="k"&gt;style&lt;/span&gt;&lt;span class="nt"&gt;&amp;gt;&lt;/span&gt;

&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Here it is. In just two steps we created simple interactive map with Vue, D3 and OpenStreetMap.&lt;/p&gt;

&lt;h2&gt;
  
  
  Conclusion
&lt;/h2&gt;

&lt;p&gt;It isn't hard to create your own map view component with the power of D3 and Vue's reactivity. I think that one of the most important things is the full control of DOM instead of using some abstract map renderer's API which will do some obscure things with my lovely elements.&lt;/p&gt;

&lt;p&gt;Of course to make a good powerful map we need to implement more features like smooth zoom, max bounds etc. But all the stuff is fully customisable so you can do everything you want or need to do.&lt;/p&gt;

&lt;p&gt;If you'll find this article useful I can write more about how to improve this map and display a data on it.&lt;/p&gt;

&lt;p&gt;Please feel free to ask your questions.&lt;/p&gt;

</description>
      <category>d3</category>
      <category>vue</category>
      <category>maps</category>
    </item>
  </channel>
</rss>
