2020-07-28
Highlight.js
[外链图片转存失败,源站可能有防盗链机制,建议将图片保存下来直接上传(img-sVFR4U8d-1595850309174)(https://travis-ci.org/highlightjs/highlight.js.svg?branch=master)] [外链图片转存失败,源站可能有防盗链机制,建议将图片保存下来直接上传(img-1P1GxVkY-1595850309324)(https://packagephobia.now.sh/badge?p=highlight.js)]
Highlight.js is a syntax highlighter written in JavaScript. It works in
the browser as well as on the server. It works with pretty much any
markup, doesn’t depend on any framework, and has automatic language
detection.
Upgrading from Version 9
Version 10 is one of the biggest releases in quite some time. If you’re
upgrading from version 9, there are some breaking changes and things you may
want to double check first.
Please read VERSION_10_UPGRADE.md for high-level summary of breaking changes and any actions you may need to take. See VERSION_10_BREAKING_CHANGES.md for a more detailed list and CHANGES.md to learn what else is new.
Getting Started
The bare minimum for using highlight.js on a web page is linking to the
library along with one of the styles and calling
initHighlightingOnLoad:
<link rel="stylesheet" href="/path/to/styles/default.css">
<script src="/path/to/highlight.min.js">script>
<script>hljs.initHighlightingOnLoad();script>
This will find and highlight code inside of tags; it tries
to detect the language automatically. If automatic detection doesn’t
work for you, you can specify the language in the class attribute:
<pre><code class="html">...code>pre>
Classes may also be prefixed with either language- or lang-.
<pre><code class="language-html">...code>pre>
Plaintext and Disabling Highlighting
To style arbitrary text like code, but without any highlighting, use the
plaintext class:
<pre><code class="plaintext">...code>pre>
To disable highlighting of a tag completely, use the nohighlight class:
<pre><code class="nohighlight">...code>pre>
Supported Languages
Highlight.js supports over 180 different languages in the core library. There are also 3rd party
language plugins available for additional languages. You can find the full list of supported languages
in SUPPORTED_LANGUAGES.md.
Custom Initialization
When you need a bit more control over the initialization of
highlight.js, you can use the highlightBlock and configure
functions. This allows you to control what to highlight and when.
Here’s an equivalent way to calling initHighlightingOnLoad using
vanilla JS:
document.addEventListener('DOMContentLoaded', (event) => {
document.querySelectorAll('pre code').forEach((block) => {
hljs.highlightBlock(block);
});
});
You can use any tags instead of to mark up your code. If
you don’t use a container that preserves line breaks you will need to
configure highlight.js to use the
hljs.configure({useBR: true});
document.querySelectorAll('div.code').forEach((block) => {
hljs.highlightBlock(block);
});
For other options refer to the documentation for configure.
Web Workers
You can run highlighting inside a web worker to avoid freezing the browser
window while dealing with very big chunks of code.
In your main script:
addEventListener('load', () => {
const code = document.querySelector('#code');
const worker = new Worker('worker.js');
worker.onmessage = (event) => { code.innerHTML = event.data; }
worker.postMessage(code.textContent);
});
In worker.js:
onmessage = (event) => {
importScripts('/highlight.min.js' );
const result = self.hljs.highlightAuto(event.data);
postMessage(result.value);
};
Node.js
You can use highlight.js with node to highlight content before sending it to the browser.
Make sure to use the .value property to get the formatted html.
For more info about the returned object refer to the api docs https://highlightjs.readthedocs.io/en/latest/api.html
// require the highlight.js library, including all languages
const hljs = require('./highlight.js');
const highlightedCode = hljs.highlightAuto('Hello World!').value
Or for a smaller footprint… load just the languages you need.
const hljs = require("highlight.js/lib/core"); // require only the core library
// separately require languages
hljs.registerLanguage('xml', require('highlight.js/lib/languages/xml'));
const highlightedCode = hljs.highlight('xml', 'Hello World!').value
ES6 Modules
First, you’ll likely install via npm or yarn – see Getting the Library below.
In your application:
import hljs from 'highlight.js';
The default import imports all languages. Therefore it is likely to be more efficient to import only the library and the languages you need:
import hljs from 'highlight.js/lib/core';
import javascript from 'highlight.js/lib/languages/javascript';
hljs.registerLanguage('javascript', javascript);
To set the syntax highlighting style, if your build tool processes CSS from your JavaScript entry point, you can also import the stylesheet directly as modules:
import hljs from 'highlight.js/lib/core';
import 'highlight.js/styles/github.css';
Getting the Library
You can get highlight.js as a hosted, or custom-build, browser script or
as a server module. Right out of the box the browser script supports
both AMD and CommonJS, so if you wish you can use RequireJS or
Browserify without having to build from source. The server module also
works perfectly fine with Browserify, but there is the option to use a
build specific to browsers rather than something meant for a server.
Do not link to GitHub directly. The library is not supposed to work straight
from the source, it requires building. If none of the pre-packaged options
work for you refer to the building documentation.
On Almond. You need to use the optimizer to give the module a name. For
example:
r.js -o name=hljs paths.hljs=/path/to/highlight out=highlight.js
CDN Hosted
A prebuilt version of highlight.js bundled with many common languages is hosted by the following CDNs:
cdnjs (link)
<link rel="stylesheet"
href="//cdnjs.cloudflare.com/ajax/libs/highlight.js/10.1.2/styles/default.min.css">
<script src="//cdnjs.cloudflare.com/ajax/libs/highlight.js/10.1.2/highlight.min.js">script>
<script charset="UTF-8"
src="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/10.1.2/languages/go.min.js">script>
jsdelivr (link)
<link rel="stylesheet"
href="//cdn.jsdelivr.net/gh/highlightjs/[email protected]/build/styles/default.min.css">
<script src="//cdn.jsdelivr.net/gh/highlightjs/[email protected]/build/highlight.min.js">script>
Note: The CDN-hosted highlight.min.js package doesn’t bundle every language. It would be
very large. You can find our list “common” languages that we bundle by default on our download page.
Self Hosting
The download page can quickly generate a custom bundle including only the languages you need.
Alternatively, you can build a browser package from source:
node tools/build.js -t browser :common
See our building documentation for more information.
Note: Building from source should always result in the smallest size builds. The website download page is optimized for speed, not size.
Prebuilt CDN assets
You can also download and self-host the same assets we serve up via our own CDNs. We publish those builds to the cdn-release GitHub repository. You can easily pull individual files off the CDN endpoints with curl, etc; if say you only needed highlight.min.js and a single CSS file.
There is also an npm package @highlightjs/cdn-assets if pulling the assets in via npm or yarn would be easier for your build process.
NPM / Node.js server module
Highlight.js can also be used on the server. The package with all supported languages can be installed from NPM or Yarn:
npm install highlight.js
# or
yarn add highlight.js
Alternatively, you can build it from source:
node tools/build.js -t node
See our building documentation for more information.
Source
Current source is always available on GitHub.
License
Highlight.js is released under the BSD License. See LICENSE file
for details.
Links
The official site for the library is at https://highlightjs.org/.
Further in-depth documentation for the API and other topics is at
http://highlightjs.readthedocs.io/.
Authors and contributors are listed in the AUTHORS.txt file.