katex
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Fast math typesetting for the web.
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# Auto-render extension
This is an extension to automatically render all of the math inside of text. It
searches all of the text nodes in a given element for the given delimiters, and
renders the math in place.
### Usage
This extension isn't part of KaTeX proper, so the script needs to be included
(via a `<script>` tag) in the page along with KaTeX itself. For example,
using a CDN:
```html
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/KaTeX/0.9.0/katex.min.css" integrity="sha384-TEMocfGvRuD1rIAacqrknm5BQZ7W7uWitoih+jMNFXQIbNl16bO8OZmylH/Vi/Ei" crossorigin="anonymous">
<script src="https://cdnjs.cloudflare.com/ajax/libs/KaTeX/0.9.0/katex.min.js" integrity="sha384-jmxIlussZWB7qCuB+PgKG1uLjjxbVVIayPJwi6cG6Zb4YKq0JIw+OMnkkEC7kYCq" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/KaTeX/0.9.0/contrib/auto-render.min.js" integrity="sha384-IiI65aU9ZYub2MY9zhtKd1H2ps7xxf+eb2YFG9lX6uRqpXCvBTOidPRCXCrQ++Uc" crossorigin="anonymous"></script>
```
Then, call the exposed `renderMathInElement` function in a script tag
before the close body tag:
```html
<body>
...
<script>
renderMathInElement(document.body);
</script>
</body>
```
See [index.html](index.html) for an example.
(To run this example from a clone of the repository, run `npm start`
in the root KaTeX directory, and then visit
http://localhost:7936/contrib/auto-render/index.html
with your web browser.)
If you prefer to have all your setup inside the html `<head>`,
you can use the following script there
(instead of the one above at the end of the `<body>`):
```html
<head>
...
<script>
document.addEventListener("DOMContentLoaded", function() {
renderMathInElement(document.body);
});
</script>
...
</head>
```
### API
This extension exposes a single function, `window.renderMathInElement`, with
the following API:
```js
function renderMathInElement(elem, options)
```
`elem` is an HTML DOM element. The function will recursively search for text
nodes inside this element and render the math in them.
`options` is an optional object argument that can have the same keys as [the
object passed to `katex.render`](https://github.com/Khan/KaTeX/#rendering-options),
in addition to two auto-render-specific keys:
- `delimiters`: This is a list of delimiters to look for math. Each delimiter
has three properties:
- `left`: A string which starts the math expression (i.e. the left delimiter).
- `right`: A string which ends the math expression (i.e. the right delimiter).
- `display`: A boolean of whether the math in the expression should be
rendered in display mode or not.
The default value is:
```js
[
{left: "$$", right: "$$", display: true},
{left: "\\[", right: "\\]", display: true},
{left: "\\(", right: "\\)", display: false}
]
```
- `ignoredTags`: This is a list of DOM node types to ignore when recursing
through. The default value is
`["script", "noscript", "style", "textarea", "pre", "code"]`.
- `errorCallback`: A callback method returning a message and an error stack
in case of an critical error during rendering. The default uses `console.error`.
Note that the `displayMode` property of the options object is ignored, and is
instead taken from the `display` key of the corresponding entry in the
`delimiters` key.