node-html-parser

A very fast HTML parser, generating a simplified DOM, with basic element query support.

Usage no npm install needed!

<script type="module">
  import nodeHtmlParser from 'https://cdn.skypack.dev/node-html-parser';
</script>

README

Fast HTML Parser NPM version Build Status

Fast HTML Parser is a very fast HTML parser. Which will generate a simplified DOM tree, with 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

npm install --save node-html-parser

Note: when using Fast HTML Parser in a Typescript project the minimum Typescript version supported is ^4.1.2.

Performance

cheerio         :12.0726 ms/file ± 7.31605
parse5          :8.18615 ms/file ± 6.15337
node-html-parser (last release):2.16533 ms/file ± 1.56924
htmlparser      :17.0658 ms/file ± 120.901
htmlparser2     :2.62695 ms/file ± 4.17579
node-html-parser:2.14907 ms/file ± 1.66632
html-parser     :24.6505 ms/file ± 18.9996
htmljs-parser   :5.81797 ms/file ± 6.55537
html-dom-parser :2.52265 ms/file ± 3.54858
html5parser     :2.01144 ms/file ± 2.53570
high5           :3.91342 ms/file ± 2.65563

Tested with htmlparser-benchmark.

Usage

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

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

Global Methods

parse(data[, options])

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

  • data, data to parse

  • options, parse options

    {
      lowerCaseTagName: false,  // convert tag name to lower case (hurts performance heavily)
      comment: false,            // retrieve comments (hurts 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 the data provided, return true if the given data is valid, and return false if not.

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: Full range of CSS3 selectors supported since v3.0.0.

HTMLElement#querySelector(selector)

Query CSS Selector to find matching node.

HTMLElement#getElementsByTagName(tagName)

Get all elements with the specified tagName.

Note: Use * for all elements.

HTMLElement#closest(selector)

Query closest element by css selector.

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#setAttributes(attrs: Record<string, string>)

Set attributes of the element.

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

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

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

HTMLElement#remove()

Remove current element.

HTMLElement#replaceWith(...nodes: (string | Node)[])

Replace current element with other node(s).

HTMLElement#classList

HTMLElement#classList.add

Add class name.

HTMLElement#classList.replace(old: string, new: string)

Replace class name with another one.

HTMLElement#classList.remove()

Remove class name.

HTMLElement#classList.toggle(className: string):void

Toggle class. Remove it if it is already included, otherwise add.

HTMLElement#classList.contains(className: string): boolean

Returns true if the classname is already in the classList.

HTMLElement#classList.values()

Get class names.

HTMLElement Properties

HTMLElement#text

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

HTMLElement#rawText

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

HTMLElement#tagName

Get or Set tag name of HTMLElement. Notice: the returned value would be an uppercase string.

HTMLElement#structuredText

Get structured Text.

HTMLElement#structure

Get DOM structure.

HTMLElement#firstChild

Get first child node.

HTMLElement#lastChild

Get last child node.

HTMLElement#innerHTML

Set or 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.

HTMLElement#textContent

Get or Set textContent of current element, more efficient than set_content.

HTMLElement#attributes

Get all attributes of current element. Notice: do not try to change the returned value.

HTMLElement#classList

Get all attributes of current element. Notice: do not try to change the returned value.

HTMLElement#range

Corresponding source code start and end indexes (ie [ 0, 40 ])