Little bundles of code, little bundles of joy.
Create minimal per-page or app-level bundles of CSS, JavaScript, or HTML to be included in your Eleventy project.
Makes it easy to implement Critical CSS, in-use-only CSS/JS bundles, SVG icon libraries, or secondary HTML content to load via XHR.
This project is a minimum-viable-bundler and asset pipeline in Eleventy. It does not perform any transpilation or code manipulation (by default). The code you put in is the code you get out (with configurable transforms if you’d like to modify the code).
For more larger, more complex use cases you may want to use a more full featured bundler like Vite, Parcel, Webpack, rollup, esbuild, or others.
But do note that a full-featured bundler has a significant build performance cost, so take care to weigh the cost of using that style of bundler against whether or not this plugin has sufficient functionality for your use case—especially as the platform matures and we see diminishing returns on code transpilation (ES modules everywhere).
It’s available on npm as @11ty/eleventy-plugin-bundle:
npm install @11ty/eleventy-plugin-bundle
And then in your Eleventy configuration file (probably .eleventy.js):
const bundlerPlugin = require("@11ty/eleventy-plugin-bundle");
module.exports = function(eleventyConfig) {
eleventyConfig.addPlugin(bundlerPlugin);
};Full options list
And then in your Eleventy configuration file (probably .eleventy.js):
const bundlerPlugin = require("@11ty/eleventy-plugin-bundle");
module.exports = function(eleventyConfig) {
eleventyConfig.addPlugin(bundlerPlugin, {
// Folder (in the output directory) bundle files will write to:
toFileDirectory: "bundle",
// Default bundle types
bundles: ["css", "js", "html"],
// Array of async-friendly callbacks to transform bundle content.
// Works with getBundle and getBundleFileUrl
transforms: []
});
};The following Universal Shortcodes (available in njk, liquid, hbs, 11ty.js, and webc) are provided by this plugin:
css,js, andhtmlto add code to a bundle.getBundleandgetBundleFileUrlto get bundled code.
Here’s a real-world commit showing this in use on the eleventy-base-blog project.
# My Blog Post
This is some content, I am writing markup.
{% css %}
em { font-style: italic; }
{% endcss %}
## More Markdown
{% css %}
strong { font-weight: bold; }
{% endcss %}Renders to:
<h1>My Blog Post</h1>
<p>This is some content, I am writing markup.</p>
<h2>More Markdown</h2>Note that the bundled code is excluded!
<!-- Use this *anywhere*: a layout file, content template, etc -->
<style>{% getBundle "css" %}</style>
<!--
You can add more code to the bundle after calling
getBundle and it will be included.
-->
{% css %}* { color: orange; }{% endcss %}Writes the bundle content to a content-hashed file location in your output directory and returns the URL to the file for use like this:
<link rel="stylesheet" href="{% getBundleFileUrl "css" %}"><!-- This goes into a `defer` bucket (the bucket can be any string value) -->
{% css "defer" %}em { font-style: italic; }{% endcss %}<!-- Pass the arbitrary `defer` bucket name as an additional argument -->
<style>{% getBundle "css", "defer" %}</style>
<link rel="stylesheet" href="{% getBundleFileUrl 'css', 'defer' %}">A default bucket is implied:
<!-- These two statements are the same -->
{% css %}em { font-style: italic; }{% endcss %}
{% css "default" %}em { font-style: italic; }{% endcss %}
<!-- These two are the same too -->
<style>{% getBundle "css" %}</style>
<style>{% getBundle "css", "default" %}</style>Use asset bucketing to divide CSS between the default bucket and a defer bucket, loaded asynchronously.
(Note that some HTML boilerplate has been omitted from the sample below)
<!-- … -->
<head>
<!-- Inlined critical styles -->
<style>{% getBundle "css" %}</style>
<!-- Deferred non-critical styles -->
<link rel="stylesheet" href="{% getBundleFileUrl 'css', 'defer' %}" media="print" onload="this.media='all'">
<noscript>
<link rel="stylesheet" href="{% getBundleFileUrl 'css', 'defer' %}">
</noscript>
</head>
<body>
<!-- This goes into a `default` bucket -->
{% css %}/* Inline in the head, great with @font-face! */{% endcss %}
<!-- This goes into a `defer` bucket (the bucket can be any string value) -->
{% css "defer" %}/* Load me later */{% endcss %}
</body>
<!-- … -->Related:
- Check out the demo of Critical CSS using Eleventy Edge for a repeat view optimization without JavaScript.
- You may want to improve the above code with
fetchprioritywhen browser support improves.
Here svg is an asset bucket on the html bundle.
<svg width="0" height="0" aria-hidden="true" style="position: absolute;">
<defs>{% getBundle "html", "svg" %}</defs>
</svg>
<!-- And anywhere on your page you can add icons to the set -->
{% html "svg" %}
<g id="icon-close"><path d="…" /></g>
{% endhtml %}
And now you can use `icon-close` in as many SVG instances as you’d like (without repeating the heftier SVG content).
<svg><use xlink:href="#icon-close"></use></svg>
<svg><use xlink:href="#icon-close"></use></svg>
<svg><use xlink:href="#icon-close"></use></svg>
<svg><use xlink:href="#icon-close"></use></svg>This might exist in an Eleventy layout file:
<head>
{% getBundle "html", "head" %}
</head>And then in your content you might want to page-specific preconnect:
{% html "head" %}
<link href="https://v1.opengraph.11ty.dev" rel="preconnect" crossorigin>
{% endhtml %}You can render template syntax inside of the {% css %} shortcode too, if you’d like to do more advanced things using Eleventy template types.
This example assumes you have added the Render plugin and the scss custom template type to your Eleventy configuration file.
{% css %}
{% renderTemplate "scss" %}
h1 { .test { color: red; } }
{% endrenderTemplate %}
{% endcss %}Now the compiled Sass is available in your default bundle and will show up in getBundle and getBundleFileUrl.
Use with WebC
Starting with @11ty/eleventy-plugin-webc@0.9.0 (track at issue #48) this plugin is used by default in the Eleventy WebC plugin. Specifically, WebC Bundler Mode now uses the bundle plugin under the hood.
To add CSS to a bundle in WebC, you would use a <style> element in a WebC page or component:
<style>/* This is bundled. */</style>
<style webc:keep>/* Do not bundle me—leave as is */</style>To add JS to a page bundle in WebC, you would use a <script> element in a WebC page or component:
<script>/* This is bundled. */</script>
<script webc:keep>/* Do not bundle me—leave as is */</script>- Existing calls via WebC helpers
getCssorgetJs(e.g.<style @raw="getCss(page.url)">) have been wired up togetBundle('css')andgetBundle('js')automatically.- For consistency, you may prefer using the bundle plugin method names everywhere:
<style @raw="getBundle('css')">and<script @raw="getBundle('js')">both work fine.
- For consistency, you may prefer using the bundle plugin method names everywhere:
- Outside of WebC, the Universal Filters
webcGetCssandwebcGetJswere available to access CSS and JS bundles but are considered deprecated in favor of new bundle plugin Universal ShortcodesgetBundle("css")andgetBundle("js")respectively.
You can wire up your own async-friendly callbacks to transform the bundle output too. Here’s a quick example of postcss integration.
const bundlerPlugin = require("@11ty/eleventy-plugin-bundle");
const postcss = require("postcss");
const postcssNested = require("postcss-nested");
module.exports = function(eleventyConfig) {
eleventyConfig.addPlugin(bundlerPlugin, {
transforms: [
async function(content) {
// Same as Eleventy transforms, this.page is available here.
let result = await postcss([postcssNested]).process(content, { from: this.page.inputPath, to: null });
return result.css;
}
]
});
};Bundling on the Edge
Coming soon
If you’d like to add your own bundle types (in addition to the guaranteed types: css, js, and html), you can do so:
const bundlerPlugin = require("@11ty/eleventy-plugin-bundle");
module.exports = function(eleventyConfig) {
eleventyConfig.addPlugin(bundlerPlugin, {
bundles: ["possum"]
});
};This does two things:
- creates a new
possumshortcode for adding arbitrary code to this bundle - adds
"possum"as an eligible type argument togetBundleandgetBundleFileUrl
Bundles do not support nesting or recursion (yet?). If this will be useful to you, please file an issue!
