prism-element - Vaadin Add-on Directory
Prism-based syntax highlighting[![Published on NPM](https://img.shields.io/npm/v/@polymer/prism-element.svg)](https://www.npmjs.com/package/@polymer/prism-element)
[![Build status](https://travis-ci.org/PolymerElements/prism-element.svg?branch=master)](https://travis-ci.org/PolymerElements/prism-element)
[![Published on webcomponents.org](https://img.shields.io/badge/webcomponents.org-published-blue.svg)](https://webcomponents.org/element/@polymer/prism-element)
## <prism-highlighter>
Syntax highlighting via [Prism](http://prismjs.com/).
Place a `` in your document, preferably as a direct child of
``. It will listen for `syntax-highlight` events on its parent element,
and annotate the code being provided via that event.
The `syntax-highlight` event's detail is expected to have a `code` property
containing the source to highlight. The event detail can optionally contain a
`lang` property, containing a string like `"html"`, `"js"`, etc.
This flow is supported by [``](https://github.com/PolymerElements/marked-element).
See: [Documentation](https://www.webcomponents.org/element/@polymer/prism-element),
[Demo](https://www.webcomponents.org/element/@polymer/prism-element/demo/demo/index.html).
## Usage
### Installation
```
npm install --save @polymer/prism-element
```
### In an html file
```html
```
### In a Polymer 3 element
```js
import {PolymerElement, html} from '@polymer/polymer';
import '@polymer/prism-element/prism-element.js';
import '@polymer/prism-element/prism-highlighter.js';
import '@polymer/prism-element/prism-theme-default.js';
class SampleElement extends PolymerElement {
static get template() {
return html`
`;
}
connectedCallback() {
super.connectedCallback();
const ev = new CustomEvent('syntax-highlight');
// enter code and language here
ev.detail = {
code: 'p { background-color: blue }',
lang: 'css',
};
this.$.parent.dispatchEvent(ev);
// detail is modified by prism-highlighter
this.$.output.innerHTML = ev.detail.code;
}
}
customElements.define('sample-element', SampleElement);
```
## Contributing
If you want to send a PR to this element, here are
the instructions for running the tests and demo locally:
### Installation
```sh
git clone https://github.com/PolymerElements/prism-element
cd prism-element
npm install
npm install -g polymer-cli
```
### Running the demo locally
```sh
polymer serve --npm
open http://127.0.0.1:/demo/
```
### Running the tests
```sh
polymer test --npm
```