JavaScript语法亮点,带有语言自动检测和零依赖性.
` tags; it tries
to detect the language automatically. If automatic detection doesn’t
work for you, or you simply prefer to be explicit, you can specify the language manually by using the `class` attribute:
```html
...
```
#### Plaintext Code Blocks
To apply the Highlight.js styling to plaintext without actually highlighting it, use the `plaintext` language:
```html
...
```
#### Ignoring a Code Block
To skip highlighting of a code block completely, use the `nohighlight` class:
```html
...
```
### Node.js on the Server
The bare minimum to auto-detect the language and highlight some code.
```js
// load the library and ALL languages
hljs = require('highlight.js');
html = hljs.highlightAuto('Hello World!
').value
```
To load only a "common" subset of popular languages:
```js
hljs = require('highlight.js/lib/common');
```
To highlight code with a specific language, use `highlight`:
```js
html = hljs.highlight('Hello World!
', {language: 'xml'}).value
```
See [Importing the Library](#importing-the-library) for more examples of `require` vs `import` usage, etc. For more information about the result object returned by `highlight` or `highlightAuto` refer to the [api docs](https://highlightjs.readthedocs.io/en/latest/api.html).
## Supported Languages
Highlight.js supports over 180 languages in the core library. There are also 3rd party
language definitions available to support even more languages. You can find the full list of supported languages in [SUPPORTED_LANGUAGES.md][9].
## Custom Usage
If you need a bit more control over the initialization of
Highlight.js, you can use the [`highlightElement`][3] and [`configure`][4]
functions. This allows you to better control *what* to highlight and *when*.
For example, here’s the rough equivalent of calling [`highlightAll`][1] but doing the work manually instead:
```js
document.addEventListener('DOMContentLoaded', (event) => {
document.querySelectorAll('pre code').forEach((el) => {
hljs.highlightElement(el);
});
});
```
Please refer to the documentation for [`configure`][4] options.
### Using custom HTML
We strongly recommend `` wrapping for code blocks. It's quite
semantic and "just works" out of the box with zero fiddling. It is possible to
use other HTML elements (or combos), but you may need to pay special attention to
preserving linebreaks.
Let's say your markup for code blocks uses divs:
```html
```
To highlight such blocks manually:
```js
// first, find all the div.code blocks
document.querySelectorAll('div.code').forEach(el => {
// then highlight each
hljs.highlightElement(el);
});
```
Without using a tag that preserves linebreaks (like `pre`) you'll need some
additional CSS to help preserve them. You could also [pre and post-process line
breaks with a plug-in][brPlugin], but *we recommend using CSS*.
[brPlugin]: https://github.com/highlightjs/highlight.js/issues/2559
To preserve linebreaks inside a `div` using CSS:
```css
div.code {
white-space: pre;
}
```
### Using with Vue.js
See [highlightjs/vue-plugin](https://github.com/highlightjs/vue-plugin) for a simple Vue plugin that works great with Highlight.js.
An example of `vue-plugin` in action:
```html
```
### Using 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:
```js
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:
```js
onmessage = (event) => {
importScripts('/highlight.min.js');
const result = self.hljs.highlightAuto(event.data);
postMessage(result.value);
};
```
## Importing the Library
First, you'll likely be installing the library via `npm` or `yarn` -- see [Getting the Library](#getting-the-library).
### Node.js CommonJS Modules / `require`
Requiring the top-level library will load all languages:
```js
// require the highlight.js library, including all languages
const hljs = require('./highlight.js');
const highlightedCode = hljs.highlightAuto('Hello World!').value
```
For a smaller footprint, load our common subset of languages (the same set used for our default web build).
```js
const hljs = require('highlight.js/lib/common');
```
For the smallest footprint, load only the languages you need:
```js
const hljs = require('highlight.js/lib/core');
hljs.registerLanguage('xml', require('highlight.js/lib/languages/xml'));
const highlightedCode = hljs.highlight('Hello World!', {language: 'xml'}).value
```
### Node.js ES6 Modules / `import`
The default import will register all languages:
```js
import hljs from 'highlight.js';
```
It is more efficient to import only the library and register the languages you need:
```js
import hljs from 'highlight.js/lib/core';
import javascript from 'highlight.js/lib/languages/javascript';
hljs.registerLanguage('javascript', javascript);
```
If your build tool processes CSS imports, you can also import the theme directly as a module:
```js
import hljs from 'highlight.js';
import 'highlight.js/styles/github.css';
```
### Browser ES6 Modules
*Note: For now you'll want to install `@highlightjs/cdn-assets` package instead of `highlight.js`.
See [Download prebuilt CDN assets](#download-prebuilt-cdn-assets)*
To import the library and register only those languages that you need:
```js
import hljs from './assets/js/@highlightjs/cdn-assets/es/core.js';
import javascript from './assets/js/@highlightjs/cdn-assets/es/languages/javascript.min.js';
hljs.registerLanguage('javascript', javascript);
```
To import the library and register all languages:
```js
import hljs from './assets/js/@highlightjs/cdn-assets/es/highlight.js';
```
*Note: The path to these files will vary depending on where you have installed/copied them
within your project or site. The above path is only an example.*
You can also use [`importmap`](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/script/type/importmap) to import in similar way as Node:
```html
```
Use the above code in your HTML. After that, your JavaScript can import using the named key from
your `importmap`, for example `@highlightjs` in this case:
```js
import hljs from '@highlightjs/core.js';
import javascript from '@highlightjs/languages/javascript.min.js';
hljs.registerLanguage('javascript', javascript);
```
*Note: You can also import directly from fully static URLs, such as our very own pre-built ES6 Module CDN resources. See [Fetch via CDN](#fetch-via-cdn) for specific examples.*
## 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][6].
**On Almond.** You need to use the optimizer to give the module a name. For
example:
```bash
r.js -o name=hljs paths.hljs=/path/to/highlight out=highlight.js
```
### Fetch via CDN
A prebuilt version of Highlight.js bundled with many common languages is hosted by several popular CDNs.
When using Highlight.js via CDN you can use Subresource Integrity for additional security. For details
see [DIGESTS.md](https://github.com/highlightjs/cdn-release/blob/main/DIGESTS.md).
#### cdnjs ([link](https://cdnjs.com/libraries/highlight.js))
##### Common JS
```html
```
##### ES6 Modules
````html
````
#### jsdelivr ([link](https://www.jsdelivr.com/package/gh/highlightjs/cdn-release))
##### Common JS
```html
```
##### ES6 Modules
```html
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