Integrations

Webpacker ships with basic out-of-the-box integration for React, Angular, Vue and Elm. You can see a list of available commands/tasks by running bundle exec rails webpacker:

React

To use Webpacker with React, create a new Rails 5.1+ app using --webpack=react option:

# Rails 5.1+
rails new myapp --webpack=react

(or run bundle exec rails webpacker:install:react in an existing Rails app already setup with Webpacker).

The installer will add all relevant dependencies using Yarn, changes to the configuration files, and an example React component to your project in app/javascript/packs so that you can experiment with React right away.

Angular with TypeScript

To use Webpacker with Angular, create a new Rails 5.1+ app using --webpack=angular option:

# Rails 5.1+
rails new myapp --webpack=angular

(or run bundle exec rails webpacker:install:angular on a Rails app already setup with Webpacker).

The installer will add the TypeScript and Angular core libraries using Yarn alongside a few changes to the configuration files. An example component written in TypeScript will also be added to your project in app/javascript so that you can experiment with Angular right away.

By default, Angular uses a JIT compiler for development environment. This compiler is not compatible with restrictive CSP (Content Security Policy) environments like Rails 5.2+. You can use Angular AOT compiler in development with the @ngtools/webpack plugin.

Alternatively if you’re using Rails 5.2+ you can enable unsafe-eval rule for your development environment. This can be done in the config/initializers/content_security_policy.rb with the following code:

Rails.application.config.content_security_policy do |policy|
  if Rails.env.development?
    policy.script_src :self, :https, :unsafe_eval
  else
    policy.script_src :self, :https
  end
end

Vue

To use Webpacker with Vue, create a new Rails 5.1+ app using --webpack=vue option:

# Rails 5.1+
rails new myapp --webpack=vue

(or run bundle exec rails webpacker:install:vue on a Rails app already setup with Webpacker).

The installer will add Vue and its required libraries using Yarn alongside automatically applying changes needed to the configuration files. An example component will be added to your project in app/javascript so that you can experiment with Vue right away.

If you’re using Rails 5.2+ you’ll need to enable unsafe-eval rule for your development environment. This can be done in the config/initializers/content_security_policy.rb with the following configuration:

Rails.application.config.content_security_policy do |policy|
  if Rails.env.development?
    policy.script_src :self, :https, :unsafe_eval
  else
    policy.script_src :self, :https
  end
end

You can read more about this in the Vue docs.

Lazy loading integration

See docs/es6 to know more about Webpack and Webpacker configuration.

For instance, you can lazy load Vue JS components:

Before:

import Vue from 'vue'
import { VCard } from 'vuetify/lib'

Vue.component('VCard', VCard)

After:

import Vue from 'vue'

// With destructuring assignment
Vue.component('VCard', import('vuetify/lib').then(({ VCard }) => VCard)

// Or without destructuring assignment
Vue.component('OtherComponent', () => import('./OtherComponent'))

You can use it in a Single File Component as well:

<template>
  ...
</template>

<script>
export default {
  components: {
    OtherComponent: () => import('./OtherComponent')
  }
}
</script>

By wrapping the import function into an arrow function, Vue will execute it only when it gets requested, loading the module in that moment.

Automatic registration

/**
 * The following block of code may be used to automatically register your
 * Vue components. It will recursively scan this directory for the Vue
 * components and automatically register them with their "basename".
 *
 * Eg. ./components/OtherComponent.vue -> <other-component></other-component>
 * Eg. ./UI/ButtonComponent.vue -> <button-component></button-component>
 */

const files = require.context('./', true, /\.vue$/i)
files.keys().map(key => {
  const component = key.split('/').pop().split('.')[0]

  // With Lazy Loading
  Vue.component(component, () => import(`${key}`))

  // Or without Lazy Loading
  Vue.component(component, files(key).default)
})

Elm

To use Webpacker with Elm, create a new Rails 5.1+ app using --webpack=elm option:

# Rails 5.1+
rails new myapp --webpack=elm

(or run bundle exec rails webpacker:install:elm on a Rails app already setup with Webpacker).

The Elm library and its core packages will be added via Yarn and Elm. An example Main.elm app will also be added to your project in app/javascript so that you can experiment with Elm right away.

Svelte

To use Webpacker with Svelte, create a new Rails 5.1+ app using --webpack=svelte option:

# Rails 5.1+
rails new myapp --webpack=svelte

(or run bundle exec rails webpacker:install:svelte on a Rails app already setup with Webpacker).

Please play with the Svelte Tutorial or learn more about its API at https://svelte.dev/docs

Stimulus

To use Webpacker with Stimulus, create a new Rails 5.1+ app using --webpack=stimulus option:

# Rails 5.1+
rails new myapp --webpack=stimulus

(or run bundle exec rails webpacker:install:stimulus on a Rails app already setup with Webpacker).

Please read The Stimulus Handbook or learn more about its source code at https://github.com/stimulusjs/stimulus

CoffeeScript

To add CoffeeScript support, run bundle exec rails webpacker:install:coffee on a Rails app already setup with Webpacker.

An example hello_coffee.coffee file will also be added to your project in app/javascript/packs so that you can experiment with CoffeeScript right away.

Erb

To add Erb support in your JS templates, run bundle exec rails webpacker:install:erb on a Rails app already setup with Webpacker and add extension ‘erb’ on file config/webpacker.yml.

An example hello_erb.js.erb file will also be added to your project in app/javascript/packs so that you can experiment with Erb-flavoured javascript right away.