Webpack loader to be used along with vue-loader for Single File Components that provides template extension.

In Vue its possible to extend the component's controller using the extends option, which merges the data, methods, computed properties, etc. Its also possible to extend a component's template with the use of slots. But in some cases where there's the need for tightly coupled components, where we want them to be a single entity but we want to reuse both template and controller logic, extends and slot aren't enough and can lead to cumbersome code.

Use this loader with caution, explore Vuer ways to implement what you need before relying on this

Install it onto your project with npm install

npm install --save-dev vue-inheritance-loader

You have to add it to your webpack configuration and it has to execute before vue-loader, for example with this config in your vue.config.js:

module.exports = {
  configureWebpack: {
    module: {
      rules: [
        {
          test: /\.vue$/,
          loader: ['vue-inheritance-loader']
        }
      ]
    }
  }
}

In the following example there's two components, BaseWidget and MapWidget, where MapWidget extends BaseWidget.

To make MapWidget's controller extend from BaseWidget's, you have to add extends: BaseWidget to the component definition, as you would do in normal Vue.

To make MapWidget's template extend from BaseWidget's, the following is needed:

• You have to add extendable to BaseWidget's template tag
• You have to add extends="[path_to_BaseWidget]" to MapWidget's template tag
• BaseWidget's template may contain <extension-point> tags
• Each <extension-point> may have a name attribute
• There can be at most one default extension point (<extension-point> without name) in the base component
• MapWidget's template must be comprised by a single <extensions> tag, where its children are <extension> tags
• Each <extension> tag may have a point attribute that references which <extension-point> it overwrites
• There can be at most one default extension (<extension> without point) in the child component

// BaseWidget.vue
<template extendable>
    <div>
        <h2>{{title}}</h2>
        <extension-point>This widget has nothing to show</extension-point>
        <div>
            <extension-point name="footer">Default footer</extension-point>
        </div>
    </div>
</template>

<script>
  export default {
    name: 'BaseWidget',
    data: function () {
      return {
        title: 'Empty widget'
      }
    },
  }
</script>

// MapWidget.vue
<template extends="./BaseWidget.vue">
    <extensions>
        <extension>
            <select v-model="country">
                <option v-for="country in countries" :value="country">
                    {{ country }}
                </option>
            </select>
            <br>
            [Here goes the map of {{country}}]
        </extension>
        <extension point="footer">
            Map widget footer
        </extension>
    </extensions>
</template>

<script>
  import BaseWidget from './BaseWidget.vue'

  export default {
    extends: BaseWidget,
    name: 'MapWidget',
    data: function () {
      return {
        country: '',
        countries: [
          'Uruguay',
          'Italy',
          'Argentina',
        ]
      }
    },
    watch: {
      country: function(){
        this.title = 'Map of ' + this.country;
      }
    },
    mounted(){
      this.country = this.countries[0];
    }
  }
</script>

This way you can access everything in BaseWidget from MapWidget as if they were the same component (they actually are in the resulting code).

Jest support is provided through vue-inheritance-loader-jest.

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.

ISC