react-html-template-loader

A Webpack loader allowing imports of HTML templates as if they were React components.

This project is a Proof of Concept that it is possible to write React pure functional components like HTML5 templates, almost as a Web Component.

Usage

./click-me-view.jsx.html

<template default>
  <button use-props="{{ props.buttonProps }}">
    Clicked {{ props.clicks }} time(s)
  </button>
</template>

./click-me-container.jsx

import React, { Component } from 'react';
 
// Import the HTML template as if it was a React component.
import ClickMeView from './click-me-view';
 
export default class ClickMeContainer extends Component {
  constructor(props) {
    super(props);
 
    this.state = { clicks: 0 };
    this.buttonProps = { onMouseDown: this.handleMouseDown.bind(this) };
  }
 
  handleMouseDown(e) {
    e.preventDefault();
    this.setState({ clicks: this.state.clicks + 1 });
  }
 
  render() {
    return (
      <ClickMeView
        buttonProps={ this.buttonProps }
        clicks={ this.state.clicks }
      />
    );
  }
}

Add the react-html-template-loader to your webpack.config.js:

{
  module: {
    loaders: [
      {
        test: /\.jsx\.html$/,
        exclude: /node_modules/,
        loader: 'babel!react-html-template'
      }
    ]
  },
  resolve: {
    extensions: [ '.jsx', '.jsx.html' ]
  }
}

Features

• Default and named imports/exports,
• Multiple template definitions in the same file,
• Explicit conditional and loop rendering,
• Props spreading,
• CSS modules.

Installation

npm install --save-dev react-html-template-loader

Background

Why this POC?

React provides a great developing experience, you finally have a strong integration between the JavaScript code and the template syntax, it feels natural to write.

But this merge isn't that good for designers who just know enough HTML and, depending on the requirements, it can be a disqualifying criteria for React.

Thanks to the pure functional components and the Presentational and Container pattern, most components are simply templates having data as input and some UI as output. What if those pure functional templates could simply be written in HTML to be easily created and modified by designers?

The purpose of this POC is to show that it is possible to use HTML components as a React pure functional component.

react-html-template-loader reconcile developers and designers. It is a Webpack loader compiling HTML templates into pure functional React components.

Demo

Some demos can be found under the demo/ folder, to launch one type in a console:

npm run demo -- <demo-path>

For example:

npm run demo -- demo/todo-list

API

Imports

Component import

Default import

Import the default export of a file.

Usage

<link rel="import" href id />

Attributes

• rel: Must be set to import for this kind of relation,
• href: Path of the file to import,
• id: Name to use to reference the default export of the file.

Example

<link rel="import" href="path/to/component" id="my-component" />

Is equivalent in ES2015 to:

import MyComponent from 'path/to/component';

Named imports

Import an export by its name. The <link> tag for a named import must be child of an other <link> tag having a href attribute.

Usage

<link rel="import" href>
  <link rel="import" [name] id />
</link>

Attributes

• rel: Must be set to import for this kind of relation,
• href: Path of the file to import,
• name (Optional): Name of the component to import, can be omitted if it is the same as id,
• id: Name to use to reference the export.

Example

<link rel="import" href="path/to/component">
  <link rel="import" id="component-one" />
  <link rel="import" name="component-two" id="component-alias" />
</link>

Is equivalent in ES2015 to:

import {
  ComponentOne,
  ComponentTwo as ComponentAlias
} from 'path/to/component';

Default and named imports

Import the default and some named exports from the same file.

Usage

<link rel="import" href id>
  <link rel="import" [name] id />
</link>

Attributes

• See default imports and named imports.

Example

<link rel="import" href="path/to/component" id="my-component">
  <link rel="import" id="component-one" />
  <link rel="import" name="component-two" id="component-alias" />
</link>

Is equivalent in ES2015 to:

import MyComponent, {
  ComponentOne,
  ComponentTwo as ComponentAlias
} from 'path/to/component';

Stylesheet import (CSS Modules)

Global stylesheet

Import a global stylesheet.

Usage

<link rel="stylesheet" href />

Attributes

• rel: Must be set to stylesheet for this kind of relation,
• href: Path of the file to import.

Example

<link rel="stylesheet" href="./global-style" />

Is equivalent in ES2015 to:

import './global-style';

Named stylesheet

Import a stylesheet and name it.

Usage

<link rel="stylesheet" href id />

Attributes

• rel: Must be set to stylesheet for this kind of relation,
• href: Path of the file to import,
• id: Value to use to reference the stylesheet.

Example

<link rel="stylesheet" href="./style" id="{{ style }}" />

Is equivalent in ES2015 to:

import style from './style';

It can be used this way:

<div class="{{ style.myClassName }}" />

Templates

A template is an HTML tag containing a single root child.

Default template

Each file must contain at most one default template. A default template is the main template of the file.

Usage

<template default [id]>
  <!-- Content -->
</template>

Attributes

• default: Flag the default template,
• id (Optional): Tag name to use to reference this template. Also used to set the displayName of the template for debug purpose.

Example

<template default id="hello-world">
  <div>Hello World</div>
</template>

Is equivalent in React to:

export default function HelloWorld() {
  return (
    <div>Hello World</div>
  );
}
HelloWorld.displayName = 'HelloWorld';

Named templates

A named template is simply a template with an id attribute, which means it can be used by referencing its name. All named templates will be exported under their given name.

Usage

<template id>
  <!-- Content -->
</template>

Attributes

• id: Tag name to use to reference this template. Also used to set the displayName of the template for debug purpose.

Example

<template id="named-template">
  <!-- ...  -->
</template>
 
<template default>
  <!-- ...  -->
  <named-template />
  <!-- ...  -->
</template>

Is equivalent in React to:

export function NamedTemplate(props) {
  return (
    // ...
  );
}
NamedTemplate.displayName = 'NamedTemplate';
 
export default function(props) {
  return (
    // ...
    <NamedTemplate />
    // ...
  );
}

Loops

A loop will render its content for each element in the array. The render tag can only have one child. When looping over an array, an id tag must be set on each child tag.

Usage

<render for-each as>
  <!-- Content -->
</render>

Attributes

• for-each: Array of data,
• as: Name of the variable to use for each element.

Example

<template default>
  <div class="users">
    <render for-each="{{ props.users }}" as="{{ user }}">
      <div key="{{ user.id }}">{{ user.name }}</div>
    </render>
  </div>
</template>

Is equivalent in React to:

export default function(props) {
  return (
    <div className="users">
      { props.users.map(user => (
        <div key={ user.id }>
          {{ user.name }}
        </div>
      )) }
    </div>
  );
}

Conditionals

A conditional will render its content depending on a condition. The render tag can only have one child.

Usage

<render if>
  <!-- Content -->
</render>

Attributes

• if: Condition to fulfill for the content to be rendered.

Example

<template default>
  <div class="user">
    <render if="{{ props.user }}">
      <div>{{ props.user.name }}</div>
    </render>
  </div>
</template>

Is equivalent in React to:

export default function(props) {
  return (
    <div className="user">
      { props.user && <div>{{ props.user.name }}</div> }
    </div>
  );
}

Props spreading

Props spreading is used to simplify the template so the focus can be kept on the UI.

Usage

<any-tag use-props>
  <!-- Content -->
</any-tag>

Attributes

• use-props: Variable that will be spread in the corresponding tag.

Example

Instead of writing:

<template default>
  <button
    on-mouse-down="{{ props.handleMouseDown }}"
    on-key-down="{{ props.handleKeyDown }}"
    on-focus="{{ props.handleFocus }}"
    on-blur="{{ props.handleBlur }}"
  >
    Clicked {{ props.clicks }} time(s)
  </button>
</template>

Just write:

<template default>
  <button use-props="{{ props.buttonProps }}">
    Clicked {{ props.clicks }} time(s)
  </button>
</template>

Which is equivalent in React to:

export default function(props) {
  return (
    <button { ...props.buttonProps }>
      Clicked { props.clicks } time(s)
    </button>
  );
}

License

MIT.