What do you think about start app using expo? Is better start app with react-native Cli?
What package do you recommend for UX?
No, I would never use Expo for a serious project. I imagine what ends up happening in most projects is they reach a point where they have to ultimately eject the app (e.g. needing a native module) which sounds very painful.
The majority of the apps I've wrote have definitely reached that point, for the individual benefits expo provide (e.g. code push) I've considered trying out using just expo kit but I'd rather just uses a tool specifically for that purpose. Above all, I always like to reduce the level of magic in any application, mobile or not.
Regarding "What package do you recommend for UX", I guess it really depends what you mean. But hopefully this gives you everything you need to know:
I'm very grateful for your answer, this is very helpful !! 😊
I use always expo because I'm starting programming in RN, but I think I will start starting project with react-native-cli.
This is a really good question, in a meeting at the moment but will definitely respond to this!
Hey kyle, that's wonderful.
I have a question for you please.
I see you use rnn just like me so how do you tackle showing perticular screen after opening app from notification.
E.g user received a notification message in a chat app As app is killed. Now user taps on the notification and app opens. Now how do you redirect to perticular chat? I tried with handleDeepLink but its slow.
If you haven't moved to RNN v2 by now, I'd recommend it ;)
Yes, i did move to RNN v2.
Cool :) I just moved a big project to it, I don't feel like it's perfect yet but still a big improvement over v1. I actually don't understand why so many people are happy with JS based navigation like react-navigation.
Hey Kyle, but could you please point out how you tackle this problem with opening app on the specific screen (using RNN v2) after clicking on push notification in tray? What package do you use for handling push notifications?
Hey Kyle, but could you please point out how you deal with opening app on specific screen after pressing push notification from tray (using rnn v2)? What package do you use for handling push notifications in conjunction with rnn v2? maybe you could point out to some great examples?
I solved this problem.. If you wish to know ? Ping me
Hey Faiz, were you able to solve this issue? could you please elaborate on what package you used for handling push notifications?
What do you think about the fluidity of react-native apps ?
So far, I've seen apps made by Chinese e-commerce giants like Alibaba's Taobao and Jindong, their apps requires lots of resources and are all very slow even on last end Android devices.
I've also seen some startup using it for chat app and it's simply become unusable after a while because all the memory leaks.
Do you think these are just poorly made app or react-native is just not ready to replace native development ?
Which app would you recommend to check out in order to see how powerful this framework can be ?
The only case I've seen that can be tricky to keep performant at the moment is when you're doing CPU heavy tasks whilst listing out uncompressed images >2mb. Memory consumption of images this size do seem to be a tricky problem, though libs like react-native-fast-image aim to solve this sort of thing.
I'd say almost certainly they were developed badly, there's no reason now why you couldn't make apps indistinguishable from native. My top tip for this is to move away from JS based navigation libraries (e.g. react-navigation), that's where you see a lot of the performance gains.
Performance wise the Patient View app I made shows this off, I sync and encrypt thousands of records and chart them out whilst keeping everything 60fps.
I see, thanks for the answer and cheers for the 100 apps, that's a hell of a pace :)
What are the most 3 troublesome issues with React Native and how did you overcome?
1 - Upgrading projects from very early versions of React Native. This has been, at times, an absolute nightmare (mainly iOS)! Especially when your project relies on several libs that require native changes. In the end, it was often easiest to create a new react native project from scratch and manually link libraries one by one.
Thankfully, this is rarely an issue now as it has matured. Having said that, I think it's really important to stay on top of React Native versions if your project has longevity.
2 - I had to integrate a react native app to read sensors for a car HUD, no simple way of overcoming this I just had to learn Objective C to write a React Native Bridge. Getting comfortable doing this is really valuable if you run into projects that require specific native functionality.
3 - Once, I hit an error which I could only replicate at the point of uploading a react native app, it would error out with "You must supply a CFBundleIdentifier for this request". This had me banging my head against my desk for a few days. In the end, it was something simple like the way I was creating my release scheme in xcode.
on #2 you said that you have to learn Obj-C.
Is is still worth it to learn Obj-C or go straight with Swift if we need to write native modules for our RN project?
I feel like it’s actually more useful to learn objc if the purpose is purely for react native. The reason I say this is a lot of the big native modules for rn are written in it, rarely came across swift implementations.
Thank you Kyle!
Appologies, I don’t have much to share around this. Though I’m sure there’s plenty of resources out there for this l.
Ok, I'll keep in mind... Thanks...
No problem! :)
How do you handle Keyboard hiding inputs ?
It's a bloody pain!
I think I've got a post somewhere in GitHub saying this is the biggest pain point at the moment with core React Native, and I posted that in 2017 github.com/facebook/react-native/i....
I just use a combination of the keyboard avoiding view and react-native-keyboard-aware-scroll-view, I've always been able to achieve what I want but it's always fiddly.
I have TV-screen where we simply run our web-app on react. I have found out that fps starts slowly go down after ~10-15 minutes. It can loose 5-7fps per hour. App starts with 58fps and goes down to 52fps in one hour.
I had a test where I have webpack + App which renders empty div. This simple app starts to loose fps in 10 minutes after launch.
Is react suitable for apps which suppose to run without clicks and refreshes for hours? (is it problem of my app or the problem of react? Is there anything what could help me?
My backup plan is to refresh the page every hour, but I am looking for a better solution.
Hey Julia, although this is more of a react than react native question I’ll see if I can help point you in the right direction. This definitely seems quite unusual and isn’t standard for react to see this.
To me it sounds like some form of leak, e.g registering event listeners that don’t get unassigned, or some recursive hell. Did you try compiling your app in production mode and running the output with a simple http-server? Also, have you tried running in chrome and inspecting memory and cpu usage?
I have tests not only on dev but also on production of other product, which has the same results. FPS slowly goes down in some time.
This is why I raised the question if react suits for such products.
Probably, there is a problem in a set-up somewhere and react is not involved in the problem at all.
Sounds fantastik! This is your glory day, horray!
Each 10th day – new app!
I would like to give you 100 hundred copy-pasted emoji beer.
What is percentage of bridging to native modules?
Low, less than 10% maybe, but I've worked on some weird projects. There's so many repos now on GitHub when comparing to 2015.
Here are the times I've had to delve into native modules.
Was anything except Keyboard Extension on iOS? For example connection ABAddressBook written on ObjectiveC.
Interesting your integration approach with CoreML for example.
All the above required me to write ObjC. The HUD app in particular required me to bridge a pretty beefy SDK that was pretty closed off to the public.
I haven't integrated with core ml, I do want to play around with using tensorflow and React Native at some point.
What is the major benefit over React (web)? Of course for apps where you need access to the users music for a music player it makes sense, but for festivals for example a web app app should be sufficient.
It ended up being an amazing app store SEO hack, a lot of the time we were the top search result for x festival - that's a lot harder to achieve on a website.
Also, quite simply, people take their phones to a festival not their laptop. This worked offline and tapped into things that only fit well on an app (e.g. find my tent, chat with image upload). It was definitely a lot easier to compete against the official app than website.
I'm working on my second app now, but this will be the first one I release. My biggest fear going in to this is not building that app, but the red tape of getting it published. With that being said, my questions are.
Good question and congrats :).
How hard much harder is it, to publish both Android and IOS, vs just IOS?
To get the last question out of the way, I'd say if you face any red tape it's almost certainly going to be on iOS side. Also the time bottleneck is going to be iOS side too, publishing can take 1-2 days but sometimes more.
What should I be prepared for when publishing my app?
I can't give you a simple one sized fits all answer here, but I would say that as long as you're not doing something outrageous you'll probably be ok. Best thing I can do is list some of the common scenarios I've found that might catch you out:
With the above being said it literally depends sometimes on who views it.
What can I do to help avoid headaches during the process?
You rock and that was greatly informative. Thank you so much.
That's alright, enjoying all these questions!
Can you help me to automate all kinds of task from building to releasing app to the store in React Native? I prefer circle ci or same kind of provider with good User Interface. I am looking for Continous Integration as well as Continous Development using React Native
Hello. I want to save my images on cloud drives(Google drive, dropbox...) with react-native app. I can't find out the exact way. I don't know which package I should use. What I have tried is getting auth but I can't understand how it works and how to manage my key or status. Can you give me any advice? Thank you for reading.
I'm supposed to develop an RN application with location tracking (foreground,background & killed state). The feature works well with standard android os's, but fails in chinese manufactured devices like Xiaomi ,OnePlus etc. I've tried various libraries and workarounds but nothing worked perfectly.
Can you suggest something on this ?
Hello mate. We are building app that will communicate with ble devices. Issue is that we need to have both ios and android app wake up almost all time because when we enter in ble range app should connect on ble bluetooth device. Any idea how to manage background workers that will work on both platforms and keep app wake up?
Do you think React Native is a good starting point for someone who is a beginner in mobile apps development i.e. never touched Android studio, Java or Kotlin & Objective C or Swift for iOS; but has web development experience?
If so, do you think one would miss out on anything say difficulty in debugging or finding out root cause of a certain issue reported by users should one not having any experience in pure mobile apps development?
It’s absolutely a good starting place! I started in the same situation apart from knowning java at the time.
Debugging I guess can be a bit slower than web depending on what you’re dealing with(e.g native level crashes), having said that the tooling is still very good. For debugging issues faced by users, using a combination of crashlytics and source maps can work really well.
-> My source uri ImagebackGround is not loading in released apk on some latest devices(Notched, Curved).
-> Running absolutely fine when i build it on device. I am using ImagebackGround inside a card of native-base.
-> My source uri is a coming from REST API JSON.
Hi There, we have built an app in React Native and have released it on IOS and Andriod. We have had reports of the white screen of death on IOS devices and so far only on iPhone 8s. The white screen appears not on the home screen or after splash screen but when taking steps beyond the home screen.
We have no issues on the simulator and therefore it is really hard to track an find. Let us know if you have any tips or start points?
Hey, unfortunately I can safely say I haven’t come across a white screen issue on any of the apps I’ve made. The only thing close is at the start screen where either the app is not registered or the packager is having issues.
How many of them do you actively maintain?
Can you give a few examples of some of them?
Only a handful, which is a bit annoying because my xcode organiser / itunes connect etc ends up looking like this :D. prntscr.com/klu0jm
A lot of them have been released for a temporary period, due to them being PoC's or only having a limited shelf life (e.g. my festival apps). Other's just get taken over by other people post MVP.
A few that I'm maintaining, I'll add to this list in the coming weeks too if there's appetite :)
Also do you have any tutorials you could point out to building react native bridges and projects which android native requires libraries written in C
I don't, and to be honest I've always been out of my comfort zone doing it. Ironically, as a result, I'm more comfortable reading ObjC than Java as I've bridged more in iOS even though I spent the first 2 years professionally writing Java.
I'd love (if I had the time) to progress more in native development, I think it'd be the thing that'd help me become a better React Native developer. Realistically you can achieve absolutely anything so long as you have the Native Code to back it up.
How we can get a better debugging experience? When I was trying to develop some React Native apps and has an error, the stack trace were so confusing. There is a way to have a great debugging session with breakpoints, watches... and don't need to keep changing our code until it works?
I guess it depends where the error sits, some errors are hard to debug yes , either errors in the render markup itself or in native modules.
However I would say apart from that it's pretty much like debugging any web app in chrome with watches and other stuff you mention. I'd even go as far as to say developing with hot reloading is better than the react/webpack equivalent.
What's your experience (if any) been like with RN-web?
We're considering rewriting an existing hybrid app to RN w/web, uses camera but no other hardware. I read above that you wouldn't recommend create-react-natve-app? For first timers, would you recommend using that, then when comfortable rewriting instead of ejecting?
I haven't used it. I love the idea of sharing web code with react native, but I don't think that idea should go as far as to share dumb components so I probably wouldn't use it. I haven't gone through the process of ejecting an app but I've been told it's really painful, but it's probably not quite as bad as rewriting from scratch.
Sharing code with web was what got me into react native in the first place, I don't think that benefit is talked about enough.
Hi Kyle, I'm new with RN and am developing now for 1 month. I was wondering if you could help me out on which version of RN is the most compatible version for app release and fewer errors, cause I've faced errors that made me downgrade a lot. Thank you so much for your attention.
I am trying to get react-native-navigation and react-native-firebase to work together. I'm fairly new to programming and I'm having trouble getting them to build. I have seperately loaded react-native-navigation with react native version 0.56 and have used the starter program for react-native-firebase but not together. How do a build them together with react-native verison 0.58?
I have some weird issue with keyboard and scrollview.
I am using KeyboardAvoidingView and KeyboardAwareScrollview components to handle the keyboard.
The case is that when the keyboard get opens the cpu goes nuts.
Do you have any suggestion for this issue?
Hello! I'm developing react native application with expo and I have very strange bug. When I add new images, they are showing in my simulator and real device when I open it local, but when I'm publish project in expo.io, and after that when I open it in expo, new images are missing. But old images are showing! I use Image and Animation.Image from react-native. When I add new svg images in SvgUri component, it's reproduce too..
example of my code:
it's dont work:
Please, help me
Thanks a lot
I really can't help you here, sorry. I don't / will not use Expo - it sounds quite specific to Expo.
Hi I'm diving into an already existing react native project, which hold a ± of 100.000 users. For now it's quite static and I was asked to add more delight and interaction to the app. On my research for this I stumbled onto the Lottie library, integrated into react-native. I tested it on my virtual machine and it looks amazing. But I have some questions though:
Is it stable to use in real life products?
Are there do's and don'ts for the use of this library? (like 'Use it for buttons, but definitely don't use it for...)
When using this in live projects, did you often have performance issues?
If you find the time I'd love it if you could enlighten me on this. :D
Have a nice day!
TD: I mainly focus on functionality and leave interaction design to colleagues. However I consistently use Lottie in production.
I am implementing a app using expo. But now i need to add a image recognition part to my app and i used the tensorflow for that. But it cannot be done with the expo. So do you have any solution rather than ejecting the app. I mean like to use the Firebase mlkit without using tensorflow or something like that.?
Hey Kyle!!! I am new to react native and i am trying to work on user location tracking and sending it to another user. since i am new to react native and fire base i am facing problem to initiate. So, can you help me with this and say what to do?
how can software engineer make a difference in a country?
Hey Kyle! I really need your advice because you're using react-native-navigation. I used RNN v2 in my first RN project and almost in the end I am having huge troubles integrating it with push notifications. It seems absolutely not convenient and buggy with very sparse documentation. Already tried react-native-fcm and wix own thing react-native-notifications. Having issues making to to play nicely. besides that on Android RNN restarts the whole app when you click on notification in the tray. Could you please tell what package do you use for notifications and possibly point to some great examples of making that work togather on both platforms?
That's a crazy work rate! Well done, man! Do you see yourself producing a similar amount over the next 3 years or will you be aiming to slow down at all? ✌🏻
There's always more side projects! :). The company I work for has definitely focused more towards making mobile apps so there will be plenty more to come!
Where do you think react-native is headed in the coming years? Do you n think it's evolving at the same pace as the native counterparts?
The biggest changes I've seen with React Native is the introduction of bigger native bridges. Proper native modules like react-native-navigation and react-native-charts-wrapper are basically making it so apps can be made to be completely indistinguishable from their native counterparts. So hopefully, assuming the community stays massive it means more of that.
I can see it easily becoming the de facto tech choice for startups. Having said that I think we'll also see React Native used more and more for parts of existing native apps that (e.g. some screens) as an attempt to gain cross platform sharing without rewriting whole apps.
Hi Kyle well done. so many projects. I'm worried about the performance for huge sets of data. How did you handle that? I would like to know your thoughts.
The performance of what with huge datasets though? I guess the main thing you'll want to be worried about when dealing with large amounts of data is how you're rendering it.
In which case, I'd say as long as you're virtualizing the rendered data (i.e. using FlatList or something similar) you'll be fine.
That being said, if you're worried, write a mock test against said data!
Hi Kyle, you were right. Just using some components and applying best practices in general we can have a good performance.
Thanks a lot.
What are most used react-native plugins in your apps?
What do you use for mobile backend ?
I've gone from having a big boilerplate with having everything I could want (e.g. camera support, contact lookup) to stripping back to what I'd use 90% of the time. It's easy enough to add modules when you want them now with react-native link.
This is what I'd consider core:
The rest is down to if I'd need it, charts, contacts etc generally all have libs nowadays.
By mobile backend do you mean what server? That totally depends on what the project is, maybe sometimes I (or maybe even sometimes the company I work for) wouldn't even have a choice on this.
If it were me developing on my own though it'd be node.
How do you manage your environment variables? I find react-native-config too complicated, I had to do a lot of complicated stuff make it work with Fastlane.
i want to implement ML with react-native, there are some packages that uses Tensorflow but they all have some open issues that need to be resolved. Need some guidance from where i start. I don't know anything about Android and Swift but do know about react-native.
For someone with a good background in Android Native development, does it worth the hassle to learn React Native or just learn Native IOS development?
React Native's benefits come into play when you start sharing across platforms (including sharing react native codebases with web), and being able to develop on a codebase where web developers could easily get onboard. That being said, I guess it comes down to how you'd find the learning curve of each. If you're not savvy with JS and don't want to reach the point of having a shared codebase with Android, maybe go with Native.
A side note on this, I think there's a real untapped opportunity for native developers to work with React Native developers to build out the box native components that perhaps they use as a toolbelt to make cross platform apps way more efficiently but perhaps offer a bit more fidelity than most React Native Apps.
I'm doing a streaming app by RN so what do you think about watcher counter when streaming? I want to track that on app caus I'm afraid that the server gonna lag whenever streaming start. And when I check in app, when the start signal from server come, the counter will be 1 only caus it write to server as same time :( I'm so sorry about my English. Pls show me the light :v
This isn't much of a react native question, but ok :D. A watcher counter would only work for 1 user vs if you're intended on doing it clientside.
Have you considered using firebase for this? Sounds like a good usecase, plus internally it'd cache it for offline use.
Hi kyle, some help here dev.to/elaziziyoussouf/react-nativ...
Will take a look
Why? Are they all useful?
They range quite drastically.
A lot of them were festival apps, they totalled around 200k downloads, not the most useful app but had a large, temporary influx of users. Around 5 of them achieved top 10 in the iOS music category.
On the other hand, one of the more useful ones of mine is Patient View, this probably the proudest points as a developer as I could literally see it helping people with people's illnesses on their day to day life
I've developed quite a few apps for startups too, definitely helps out people with tight budgets who can't afford two native developers and a website developer.
How do you cost the application?
We started out costing an iOS build and then adding like 20-30 % at the end for an Android build. However now because of the parity in React Native they can now be costed as 1 build. It's not hard anymore to keep things consistent between platforms IMO.
There might be flat costs for things like getting iTunes to connect and play store builds up and running and maybe doing a sweep through on Android and iOS to ensure consistency.
Apart from that, pretty much no different to how I cost for the web. This might be a bit out of scope for the AMA but here's the high level:
Depending on the project might start with very quick PoC to test things are feasible or further research into how the industry works and if we are likely to run into any issues that could affect cost.
Add high-level estimates for "epics" based with cost being time estimated, contingency assessment on some of the more unknowns which might add a 10-20%.
With the help of the client, break those stories down into more detail and organise into sprints of work, then work/charge on an agile basis from there.
I want to create a custom keyboard in react native for my app. Couldn't find a way to do it. If you can provide a guide for this. It will be appreciated.
I have done this before as a PoC as well as doing a native iOS widget. I don't think I'll have enough time in the coming weeks to cover this, but It's not that much more effort than the standard native way of doing it. Sorry if this isn't much help, however I can say I used this as a base facebook.github.io/react-native/do...
Do you use redux/mobx/context/pure graphql? How would you decide what to use or migrate to?
Hey guys, I'll try and find some free time to answer these remaining questions! I have been reading them so don't worry.
I want to auto upload photos from a users camera roll to the back end with react native ,but I can’t understand how to do so ,can u please help
I need to store and display simple chart data(date, value) using react native and firebase. Any suggestions?
I wouldn't use anything other than react-native-charts-wrapper, it's native and not JS based.
EDIT: Having said this, if you have a very bespoke design requirement I've actually tried implementations that use webview - they work really well, better than I'd have expected.
I picked this up from noticing FusionCharts had react native support which surprised me, only to find their implementation github.com/fusioncharts/react-nati.... But I can't complain, I've seen really good results from it.
And the second question, Can we actually make a widget of an application that is built using React Native? If yes, then how can we do that effectively? Do we have any limitation here?
I am not a devops guy but I have to make a basic config for building and testing react-native run-ios on the gitlab ci. Can you help me with that, i.e. , if you have built one previously.
Could you recommend how to build a list chat app for large performance and 10.000 people at the same time. I've faced a huge problem when a chat always crash memory leak in android. Thank you so much.
Always make sure that your messages are only rendering once (unless there’s a legitimate reason to update it) github.com/kyle-ssg/react-native-r... pop this into your message component to validate that it stays at 1.
Also check it any other expensive components are rendering as a result on your page. You should aim for a new message to not cause any other components to render. A mixture of keys, purecomponent/shouldcomponentupdate should help here.
Don’t declare functions in the render function if you can avoid it, do this.funcName.
If you’re getting 100s of simultaneous messages updating render state, consider denouncing the render perhaps. So 10 messages in 100ms only calls setstate once.
Have you tried ReactXP or react-native-web? I'm curious how much code could actually share RN code with React web projects.
I guess it depends on the project. I have but I purely use it for APIs like NetInfo and asyncstorage. I don’t really like the idea of presentational components being shared between rn and web, I prefer sharing just about everything else
How well do your apps scale? Have you read about AirBnB's use of React Native and their decision to not use it any more?
I have yes, I feel like a lot of their challenges were quite specific to their company. I work for an agency where the benefits of cross platform development have made a huge impact for them and businesses we've made apps for.
Would u suggest to a newbie to cross platform development to use RN instead of flutter. If so, why?
Im using Expo and can't get SVG local files to show.
I don't use Expo in my projects, and probably never will. However, I do use SVGs.
I haven't ever loaded svgs from a uri (which I assume is what you're doing, it probably uses react-native-svg-uri) internally. Have you tried just rendering the svg markup - this is a handy tool smooth-code.com/open-source/svgr/p...
How do you maintain reusable styling throughout the application? Do you think styled-components can solve this problem?
A global stylesheet for grid / layout, stylesheets per component other than that. I'd only personally use styled components that need dynamic theming. Having local stylesheets and well componentised app + what I'd call a markup page (where you dump all of your components on 1 page separate from the app) provides all the benefits I need around this.
Edit: I need to go over in a post how much this idea of a markup page has helped out myself and other developers in our projects. It can make a huge difference.
How can i use a custom trained model ( tensorflow_inception_graph.pb & tensorflow_labels.txt ) in my react native project.
Ur number pls
Am need to react native
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