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Nikos Koikas
Nikos Koikas

Posted on • Updated on

Writing a very simple plugin in Vue.js - (Example)

  • What is a Vue Plugin?
  • Writing and using a plugin

In this post, i will be showing you how you can write a basic plugin in Vue.
You should have a prior experience with Vue and JavaScript.

What is a Vue Plugin?

Enables you to add global-level functionality to Vue.
It's a good way to keep your Vue components clear and small. You can also package and share your code with other developers.
Specifically, plugin is nothing more than an object which expose an install method.

Writing and using a plugin

Firstly, you should export the plugin object, so it can be used anywhere in your project. Then expose the install method which takes two parameters: Vue constructor and options object. The second parameter - options - is optional and customize your plugin.
plugin.js

// plugin.js

// This exports the plugin object.
export default {
  // The install method will be called with the Vue constructor as
  // the first argument, along with possible options
  install (Vue, options) {
  }
}
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But a question which arises is where do I provide these options?

OK. You can call use() method and pass yourPlugin and your options as arguments, since you have already imported your plugin.js into main.js file.

main.js

// main.js

import Vue from 'vue'
import yourPlugin from './plugin.js'

// Without options
Vue.use(yourPlugin)
// With options
Vue.use(yourPlugin, {
    someOption: true
})

new Vue({
  el: '#app',
  render: h => h(App)
})
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Install method - Plugins
The install method contains one or more of the following:

  • Add some global methods or properties.
  • Add one or more global assets: directives/filters/transitions etc.
  • Add some component options by global mixin.

Mixins are a flexible way to distribute reusable functionalities for Vue components. A mixin object can contain any component options. When a component uses a mixin, all options in the mixin will be “mixed” into the component’s own options.

  • Add some Vue instance methods by attaching them to Vue.prototype.
// plugin.js
import Component from '/src/components/Component.vue'

// This exports the plugin object.
export default {
  // The install method will be called with the Vue constructor as         
  // the first argument, along with possible options
  install (Vue, options) {
     // Add or modify global methods or properties.
     Vue.yourMethod = (value) => value
     // Add a component or directive to your plugin, so it will be installed globally to your project.
     Vue.component('component', Component)
     // Add `Vue.mixin()` to inject options to all components.
     Vue.mixin({
         // Add component lifecycle hooks or properties.
         created() {
            console.log('Hello from created hook!')
         }
     })
     // Add Vue instance methods by attaching them to Vue.prototype.
     Vue.prototype.$myProperty = 'This is a Vue instance property.'
  }
}
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Now, let's take a deep dive into our example's code

-------- EXAMPLE ---

Distributing

So you have built your first plugin in Vue. It's time to distribute it to the community - if you want.

  • Upload the source files to Github and then
  • Publish the package to NPM.

Until next time...Happy coding!

Top comments (7)

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asgouros profile image
asgouros

Vue.property.$myProperty there is an error there, should be Vue.prototype.$myProperty

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michealjroberts_57 profile image
Michael J. Roberts • Edited

Although I 100% like and use this method - it does throw an ESLint error:

error: Assignment to property of function parameter 'Vue' (no-param-reassign) at src/plugins/plugin.js:5:5:

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michaelgitart profile image
Michael

Thanks, realy great guide!

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dylajwright profile image
Dylan

This is a great simple guide, pairing it with unit tests would be even better almost perfect.

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yavuztas profile image
Yavuz Tas

Thank you for your explanation. It helped me a lot!

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nekooee profile image
nekooee

how can I publish it in npm???

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nirnejak profile image
Jitendra Nirnejak

Great article, I would also recommend checking out this article about the same
inkoop.io/blog/building-custom-plu...