Partials for HTML Webpack Plugin

Extends HTML Webpack Plugin to add support for partials or templates.

Requirements

Relies on html-webpack-plugin 4+ (currently at beta)

Installation

yarn add html-webpack-partials-plugin -D

npm add html-webpack-partials-plugin --save-dev

Usage

Require the plugin in your webpack config:

const HtmlWebpackPartialsPlugin = require('html-webpack-partials-plugin');

Add the plugin to your webpack config as follows:

plugins: [
  new HtmlWebpackPlugin(),
  new HtmlWebpackPartialsPlugin({
    path: './path/to/partials/body.html'
  })
]

Set up your partial:

<div>Hello World!</div>

Settings

Name	Type	Default	Description
path	String	none	Partial location
inject	Boolean	true	Conditionally inject your partial
location	String	"body"	HTML tag name where the the partial gets added
priority	String	"low"	"high", "low", "replace" - high/low determines if the partial gets added from the start of the location or end, while replace replaces the element completely.
template_filename	String/String[]	"index.html"	The filename of the HTML Webpack Plugin template that the partial should be attributed to. By default this is `index.html`, the HTML Webpack Plugin default output. Additionally, passing `` will apply the partial to all templates in the compilation. This doesn't currently work in a regex format, thus something like `.html` will NOT work and the only functionality `*` will provide is to match all templates. You can also pass an array of strings.
options	Object	{}	Local variables/options to the given partial

The settings can either be passed in as a single object or an array of objects.

Examples

React App Root

Don't bother creating a custom template just to add a React root element, simply add it as a partial!

Set Up Your Config

Using an example of webpack.config.js with Babel installed:

const path = require('path');
const HtmlWebpackPlugin = require('html-webpack-plugin');
const HtmlWebpackPartialsPlugin = require('../../');

module.exports = {
  entry: {
    main: path.join(__dirname, './main.js')
  },
  output: {
    path: path.join(__dirname, './dist'),
    filename: '[name].js'
  },
  module: {
    rules: [
      {
        test: /\.js$/,
        exclude: /node_modules/,
        use: {
          loader: 'babel-loader',
          options: {
            presets: [
              '@babel/preset-env',
              '@babel/preset-react'
            ]
          }
        }
      }
    ]
  },
  plugins: [
    new HtmlWebpackPlugin(),
    new HtmlWebpackPartialsPlugin({
      path: path.join(__dirname, './partials/body.html')
    })
  ]
};

Set Up your Partial

Add a mounting point for your application at partials/body.html:

<div id="root"></div>

Results

💪Now your app has something to render to!

<!DOCTYPE html>
<html>
  <head>
    <meta charset="UTF-8">
    <title>Webpack App</title>
  </head>
  <body>
  <div id="root"></div><script type="text/javascript" src="main.js"></script></body>
</html>

Google Analytics & Google Optimize

The recommended installation of Google Optimize alongside Google Analytics includes installing the snippet immediately after the <meta charset tag from the initial server-returned HTML. Loading this clientside using something like React Helmet, unless using server side rendering, won't give us the benefits of giving an optimal loading experience when running A/B tests. To fix this, we can inject this snippet using a partial without having to create a custom HTML template file or trying to sloppily manage it in our app.

Set Up Your Config

Using a basic example of webpack.config.js:

const path = require('path');
const HtmlWebpackPlugin = require('html-webpack-plugin');
const HtmlWebpackPartialsPlugin = require('../../');

module.exports = {
  entry: {
    main: path.join(__dirname, './main.js') // Not shown in thix example
  },
  output: {
    path: path.join(__dirname, './dist'),
    filename: '[name].js'
  },
  plugins: [
    new HtmlWebpackPlugin(),
    new HtmlWebpackPartialsPlugin([
      {
        path: path.join(__dirname, './partials/analytics.html'),
        priority: 'high',
        location: 'head'
      }
    ])
  ]
};

Set Up your Partial

Using example code from the installation guide, set up partials/analytics.html:

<!-- Page-hiding snippet (recommended)  -->
<style>.async-hide { opacity: 0 !important} </style>
<script>(function(a,s,y,n,c,h,i,d,e){s.className+=' '+y;h.start=1*new Date;
h.end=i=function(){s.className=s.className.replace(RegExp(' ?'+y),'')};
(a[n]=a[n]||[]).hide=h;setTimeout(function(){i();h.end=null},c);h.timeout=c;
})(window,document.documentElement,'async-hide','dataLayer',4000,
{'GTM-XXXXXX':true});</script>

<!-- Modified Analytics tracking code with Optimize plugin -->
<script>
(function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
(i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),
m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)
})(window,document,'script','https://www.google-analytics.com/analytics.js','ga');

ga('create', 'UA-XXXXXXXX-X', 'auto');
ga('require', 'GTM-XXXXXX');
ga('send', 'pageview');
</script>

Results

🙆 now you're analytics code can be easily maintained and installed in the right spot!

<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8"><!-- Page-hiding snippet (recommended)  -->
<style>.async-hide { opacity: 0 !important} </style>
<script>(function(a,s,y,n,c,h,i,d,e){s.className+=' '+y;h.start=1*new Date;
h.end=i=function(){s.className=s.className.replace(RegExp(' ?'+y),'')};
(a[n]=a[n]||[]).hide=h;setTimeout(function(){i();h.end=null},c);h.timeout=c;
})(window,document.documentElement,'async-hide','dataLayer',4000,
{'GTM-XXXXXX':true});</script>

<!-- Modified Analytics tracking code with Optimize plugin -->
<script>
(function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
(i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),
m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)
})(window,document,'script','https://www.google-analytics.com/analytics.js','ga');

ga('create', 'UA-XXXXXXXX-X', 'auto');
ga('require', 'GTM-XXXXXX');
ga('send', 'pageview');
</script>
    <title>Webpack App</title>
  </head>
  <body>
  <script type="text/javascript" src="main.js"></script></body>
</html>

Other Examples

See a few other working examples here: https://html-webpack-partials-plugin.netlify.app/

See the source for the examples here: https://github.com/colbyfayock/html-webpack-partials-plugin/tree/master/examples

Notes

Determining Injection Point

Given the location and priority passed into the configuration, the plugin determines where to inject. The location is simply the name of the tag to use, where the priority is how high or how low in the tag we inject. For almost all situations, a high priority will inject immediately after the opening tag and low will inject immediately before the closing tag.

The one exception to this, if the passed in tagname is head with a high priority, the plugin will inject immediately after <meta charset="utf-8">.