# Fast HTML Parser [![NPM version](https://badge.fury.io/js/node-html-parser.png)](http://badge.fury.io/js/node-html-parser) [![Build Status](https://travis-ci.org/taoqf/node-html-parser.svg?branch=master)](https://travis-ci.org/taoqf/node-html-parser)

Fast HTML Parser is a _very fast_ HTML parser. Which will generate a simplified
DOM tree, with basic element query support.

Per the design, it intends to parse massive HTML files in lowest price, thus the
performance is the top priority.  For this reason, some malformatted HTML may not
be able to parse correctly, but most usual errors are covered (eg. HTML4 style
no closing `<li>`, `<td>` etc).

## Install

```shell
npm install --save node-html-parser
```

## Performance

Faster than htmlparser2!

```shell
node-html-parser:2.02346 ms/file ± 2.21481
htmlparser      :26.0810 ms/file ± 171.313
htmlparser2     :4.49111 ms/file ± 6.85512
parse5          :14.8590 ms/file ± 10.9427
high5           :7.71818 ms/file ± 4.88375
```

Tested with [htmlparser-benchmark](https://github.com/AndreasMadsen/htmlparser-benchmark).

## Usage

```ts
import { parse } from 'node-html-parser';

const root = parse('<ul id="list"><li>Hello World</li></ul>');

console.log(root.firstChild.structure);
// ul#list
//   li
//     #text

console.log(root.querySelector('#list'));
// { tagName: 'ul',
//   rawAttrs: 'id="list"',
//   childNodes:
//    [ { tagName: 'li',
//        rawAttrs: '',
//        childNodes: [Object],
//        classNames: [] } ],
//   id: 'list',
//   classNames: [] }
console.log(root.toString());
// <ul id="list"><li>Hello World</li></ul>
root.set_content('<li>Hello World</li>');
root.toString();	// <li>Hello World</li>
```

```js
var HTMLParser = require('node-html-parser');

var root = HTMLParser.parse('<ul id="list"><li>Hello World</li></ul>');
```

## Global Methods

### parse(data[, options])

Parse given data, and return root of the generated DOM.

- **data**, data to parse
- **options**, parse options

  ```js
  {
    lowerCaseTagName: false,  // convert tag name to lower case (hurt performance heavily)
    comment: false            // retrieve comments (hurt performance slightly)
    blockTextElements: {
      script: true,	// keep text content when parsing
      noscript: true,	// keep text content when parsing
      style: true,		// keep text content when parsing
      pre: true			// keep text content when parsing
    }
  }
  ```

### valid(data[, options])

Parse given data, return the root element if the givent data is valid, and return false if not valid.

## HTMLElement Methods

### HTMLElement#trimRight()

Trim element from right (in block) after seeing pattern in a TextNode.

### HTMLElement#removeWhitespace()

Remove whitespaces in this sub tree.

### HTMLElement#querySelectorAll(selector)

Query CSS selector to find matching nodes.

Note: only `tagName`, `#id`, `.class` selectors supported. And not behave the
same as standard `querySelectorAll()` as it will _stop_ searching sub tree after
find a match.

### HTMLElement#querySelector(selector)

Query CSS Selector to find matching node.

### HTMLElement#appendChild(node)

Append a child node to childNodes

### HTMLElement#insertAdjacentHTML(where, html)

parses the specified text as HTML and inserts the resulting nodes into the DOM tree at a specified position.

### HTMLElement#setAttribute(key: string, value: string)

Set `value` to `key` attribute.

### HTMLElement#removeAttribute(key: string)

Remove `key` attribute.

### HTMLElement#getAttribute(key: string)

Get `key` attribute.

### HTMLElement#exchangeChild(oldNode: Node, newNode: Node)

Exchanges given child with new child.

### HTMLElement#removeChild(node: Node)

Remove child node.

### HTMLElement#toString()

Same as [outerHTML](#htmlelementouterhtml)

### HTMLElement#set_content(content: string | Node | Node[])

Set content. **Notice**: Do not set content of the **root** node.

### HTMLElement#remove()

Remove current element.

## HTMLElement Properties

### HTMLElement#text

Get unescaped text value of current node and its children. Like `innerText`.
(slow for the first time)

### HTMLElement#rawText

Get escpaed (as-it) text value of current node and its children. May have
`&amp;` in it. (fast)

### HTMLElement#structuredText

Get structured Text

### HTMLElement#structure

Get DOM structure

### HTMLElement#firstChild

Get first child node

### HTMLElement#lastChild

Get last child node

### HTMLElement#innerHTML

Get innerHTML.

### HTMLElement#outerHTML

Get outerHTML.

### HTMLElement#nextSibling

Returns a reference to the next child node of the current element's parent.

### HTMLElement#nextElementSibling

Returns a reference to the next child element of the current element's parent.