eleventy-plugin-helmet
v0.2.2
Published
A document head manager for Eleventy.
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eleventy-plugin-helmet
A document head manager for Eleventy.
This Eleventy plugin will manage any elements you want to append to the document head.
In your templates, annotate any HTML tag inside the body with a data-helmet attribute, and it will be outputted in the document head.
Features
- Supports any tag located in
body. - Supports passing a unique indentifier to the
data-helmetattribute to avoid tag duplication (see Example below).
Example
Assume variable home is set to true for the homepage (index.html), and false otherwise.
layout.njk:
<!doctype html>
<html lang="en">
<head>
<link rel="stylesheet" href="/main.css" />
</head>
<body>
{% if home %}
{% include "home.njk" %}
{% else %}
{% include "not-home.njk" %}
{% endif %}
<link rel="stylesheet" href="/page.css" data-helmet="page-css" />
</body>
</html>home.njk:
<h1>Title</h1>
<p>Hello World!</p>
<link rel="stylesheet" href="/home.css" data-helmet="page-css" />
<title data-helmet>Title</title>
<meta name="description" content="Hello World!" data-helmet />not-home.njk
<h1>Some Page</h1>
<p>Some Page Content!</p>
<title data-helmet>Some Page</title>
<meta name="description" content="Some Page Content!" data-helmet />outputs:
index.html:
<!doctype html>
<html lang="en">
<head>
<link rel="stylesheet" href="/main.css" />
<link rel="stylesheet" href="/home.css" />
<title>Title</title>
<meta name="description" content="Hello World!" />
</head>
<body>
<h1>Title</h1>
<p>Hello World!</p>
</body>
</html>not-home.html:
<!doctype html>
<html lang="en">
<head>
<link rel="stylesheet" href="/main.css" />
<title>Some Page</title>
<meta name="description" content="Some Page Content!" />
<link rel="stylesheet" href="/page.css" />
</head>
<body>
<h1>Some Page</h1>
<p>Some Page Content!</p>
</body>
</html>Installation
$ npm install --save eleventy-plugin-helmet
In your .eleventy.js file, register the plugin:
const eleventyHelmetPlugin = require('eleventy-plugin-helmet');
module.exports = (eleventyConfig) => {
eleventyConfig.addPlugin(eleventyHelmetPlugin);
};Advanced: Using Helmet with an Existing PostHTML Pipeline
If you happen to have existing Eleventy transforms leveraging PostHTML, you can hook this plugin into the pipeline like so:
const { postHtmlPlugin: eleventyHelmetPlugin } = require('eleventy-plugin-helmet');
module.exports = (eleventyConfig) => {
const pipeline = postHtml()
.use(...) // Your other PostHTML plugins.
.use(eleventyHelmetPlugin);
eleventyConfig.addTransform('postHtml', async (content, outputPath) => {
if (outputPath.endsWith('.html')) {
const { html } = await pipeline.process(content);
return html;
}
return content;
});
}Use Cases
This plugin promotes structuring your templates independent from each other - your layout template no longer has to be responsible to e.g. add stylesheets only if a certain child template is loaded. Instead, add a Helmet tag to the child template directly, and the stylesheet will only be embedded when it is really needed.
Other use cases include:
- Content Security Policy (CSP) tags.
- Resource Hints.
Compatibility
Internally, this plugin uses an async PostHTML pipeline, and therefore requires Eleventy >= 0.7.
Changelog
See the CHANGELOG for a list of changes.
License
The MIT License (MIT)
Copyright (c) 2020 Mark van Seventer
Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
the Software, and to permit persons to whom the Software is furnished to do so,
subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.