Browser Vue Loader

Browser Vue Loader is a single file JavaScript library that loads untranspile Vue applications into the browsers.

This loader is ideal for rapid prototyping. With the loader, you don't have to configure built tools, but rather write the application code and run them in the browser.

In many ways, this loader behaves very similar to the vue-loader for Webpack. The major difference is that this loader does not access the local file system and requires no build steps.

We prefer convention over configuration in this loader. You can load Vue's single-file component, ES module, NPM packages, SASS styles and even images directly!

Usage

The Preferred Way

Include the loader and write your script within a <script type="boom!">.

<script src="https://unpkg.com/browser-vue-loader"></script>

<script type="boom!">
import Vue from 'vue';
import App from './path-to-your/App.vue';
new Vue({
  render: h => h(App)
}).$mount('#app')
</script>

But You Also Can

Include Vue and the loader into your HTML file. And you can load Vue modules by the loadVue function. The loaded module will be returned as a promise.

<div id="app"></div>

<script src="https://unpkg.com/vue"></script>
<script src="https://unpkg.com/browser-vue-loader"></script>

<script>
loadVue('./App.vue').then(App => {
  new Vue({
    render: h => h(App)
  }).$mount('#app')
})
</script>

Supporting Features

Loads Vue single-file components from a URL

The loadVue method can load Vue single-file components. The method takes only one argument, which is the URL of the file to be fetched from. The URL must be either relative or full, such as ./App.vue or http://example.com/path/to/App.vue.

In the following example, we load the ./single-file-app.vue component by loadVue('./single-file-app.vue'). The loadVue method will return a Promise of the component. When the promise is resolved, we can create the Vue app by mounting it to a DOM element.

loadVue('./single-file-app.vue').then(App => {
  new Vue({
    render: h => h(App)
  }).$mount('#app')
})

➡️ Vue's Single-File Component 📋 Source Code

Loads any ES module from a URL

Beside Vue single-file components, the loader can actually load any ES module to the web page.

In the following example, a ES component is loaded by loadVue('./sample-es-module').

➡️ Load ES Module 📋 Source Code

Use `import` statement as usual

In the <script type="boom!"> or your source code, you can also use the import statement to load another module. Just as what you would do normally with webpack and babel configured.

import App from './App.vue';

The loader's module system is based on the WhatWG loader specification, which describes the behavior of loading JavaScript modules from a JavaScript host environment.

A more complete example of a Vue application is the TODO MVC, which contains of two components App.vue and Todos.vue.

➡️ TODO MVC 📋 Source Code

Loads a CommonJS or AMD module from a URL or NPM registry

The loader can directly load a CommonJS or AMD module from NPM registry, if the name of the module cannot be resolved to a valid URL.

For example, by writing

import Vue from 'vue';

The loader will realise that the string vue is not a valid URL, so it will search for the package use the unpkg.com CDN. The actual URL of the module will be resolved to https://unpkg.com/vue@2.5.16/dist/vue.js.

By default, the loader will process the module as a CommonJS module. You can specify the process by adding the prefix <processor>! to the module name.

For example, the following 2 import statements are working.

import Vue from 'commonjs!vue';  // Treat the module as a CommonJS module
import _ from 'amd!lodash';  // Treat the module as an AMD module

➡️ Load Lodash 📋 Source Code

Use Vuex

Vuex is a aentralized state management library for Vue. You can use Vuex in your project with this loader.

import Vue from 'vue'
import Vuex from 'vuex'
import { state, mutations } from './mutations'
import plugins from './plugins'

Vue.use(Vuex)

export default new Vuex.Store({
  state,
  mutations,
  plugins
})

➡️ TODO MVC 📋 Source Code

Functional component by template

You can write Vue's functional component in a .vue file. All you need is to mark the <template> to be functional, as the example below.

<template functional>
  <div>
    <h1 class="inside">Hello from {{ props.location }}!</h1>
  </div>
</template>

➡️ Functional Component 📋 Source Code

Use JSX

Sometimes you may wish to write a render function instead of a template. JSX allows you to write something similar to HTML tags inside JavaScript.

<script>
  import HelloComponent from './hello-component.vue'

  export default {
    data () {
      return {
        msg: 'Hello!'
      }
    },

    render: function (h) {
      return (
        <div>
          <h1 class="outside">{ this.msg }</h1>
          <HelloComponent location="the other side" />
        </div>
      )
    }
  }
</script>

➡️ Vue with JSX 📋 Source Code

Scoped CSS

Scoped CSS is supported in single-file components.

<style scoped>
.example {
  color: red;
}
</style>

<template>
  <div class="example">hi</div>
</template>

➡️ Scoped CSS 📋 Source Code

Note: the second line in this example is created by the child component with a scoped CSS style setting the color to blue.

SASS (with both SCSS and SASS style)

Feel free to use SASS in the single-file component. CSS processors are already configured for you.

<style lang="scss">
  $purple-color: rgb(128, 0, 128);
  .purple {
    color: $purple-color;
  }
</style>

➡️ SASS 📋 Source Code

Use @import in CSS or SASS

You can use @import in the CSS or SASS code.

The loader will convert them into a special ES module and add to the registry. Same file will not be downloaded twice.

In the single-file component:

<style lang="scss">
  @import "sample-scss";
  .pink {
    color: $pink-color;
  }
</style>

In sample-scss.scss

$pink-color: rgb(255, 192, 203)

➡️ CSS @import 📋 Source Code

CSS Modules

Modularize your CSS by CSS Modules. They are supported!

For example, the .banana style below can be accessed by this.$style.banana.

<style module>
  .banana {
    color: yellow;
  }
</style>

And the .orange style below can be accessed by this.namedModule.orange.

<style module="namedModule">
  .orange {
    color: orange;
  }
</style>

➡️ CSS Modules 📋 Source Code

Images

A web page is not complete without images. You can import images as if an ES module, and use them like a URL.

The image will be fetched and converted to base64 data URL automatically.

<template>
  <div class="app">
    <img class="image-1" :src="pngImage" />
    <img class="image-2" :src="svgImage" />
  </div>
</template>

<script>
  import pngImage from "./logo.png"
  import svgImage from "./logo.svg"

  export default {
    data () {
      return {pngImage, svgImage}
    }
  }
</script>

➡️ Import Images 📋 Source Code

Contributors's Guide

Want to contribute to this loader? That's great!

We recommend you to use yarn to manage the dependencies. However, you can certainly use npm instead.

After cloning the repository, use yarn command to install the dependencies. Other commands and their descriptions are below.

Command	Description
`yarn`	Install the dependencies.
`yarn dev`	Run the webpack dev server.
`yarn build`	Build the library.
`yarn test`	Run the test cases with karma.
`yarn start-test`	Start karma test runner.
`yarn run-test --grep="Test Name"`	Run single test.

Note: we chose to commit dist directory to git for convenience. There is so far no issue for it. However we might consider ignoring it from our git repository if it grows too big one day.

Credits

The cat in our banner is from the openclipart.org.

anhoev/browser-vue-loader