# 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://img.shields.io/endpoint.svg?url=https%3A%2F%2Factions-badge.atrox.dev%2Ftaoqf%2Fnode-html-parser%2Fbadge%3Fref%3Dmain&style=flat)](https://actions-badge.atrox.dev/taoqf/node-html-parser/goto?ref=main) 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 `
  • `, `` etc). ## Install ```shell 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 -- 2022-08-10 ```shell html-parser :24.1595 ms/file ± 18.7667 htmljs-parser :4.72064 ms/file ± 5.67689 html-dom-parser :2.18055 ms/file ± 2.96136 html5parser :1.69639 ms/file ± 2.17111 cheerio :12.2122 ms/file ± 8.10916 parse5 :6.50626 ms/file ± 4.02352 htmlparser2 :2.38179 ms/file ± 3.42389 htmlparser :17.4820 ms/file ± 128.041 high5 :3.95188 ms/file ± 2.52313 node-html-parser:2.04288 ms/file ± 1.25203 node-html-parser (last release):2.00527 ms/file ± 1.21317 ``` Tested with [htmlparser-benchmark](https://github.com/AndreasMadsen/htmlparser-benchmark). ## Usage ```ts import { parse } from 'node-html-parser'; const root = parse(''); 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()); // root.set_content('
  • Hello World
  • '); root.toString(); //
  • Hello World
  • ``` ```js var HTMLParser = require('node-html-parser'); var root = HTMLParser.parse(''); ``` ## Global Methods ### parse(data[, options]) Parse the data provided, and return the root of the generated DOM. - **data**, data to parse - **options**, parse options ```js { lowerCaseTagName: false, // convert tag name to lower case (hurts performance heavily) comment: false, // retrieve comments (hurts performance slightly) voidTag:{ tags: ['area', 'base', 'br', 'col', 'embed', 'hr', 'img', 'input', 'link', 'meta', 'param', 'source', 'track', 'wbr'], // optional and case insensitive, default value is ['area', 'base', 'br', 'col', 'embed', 'hr', 'img', 'input', 'link', 'meta', 'param', 'source', 'track', 'wbr'] closingSlash: true // optional, default false. void tag serialisation, add a final slash
    }, 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. ## Class ```mermaid classDiagram direction TB class HTMLElement{ this trimRight() this removeWhitespace() Node[] querySelectorAll(string selector) Node querySelector(string selector) HTMLElement[] getElementsByTagName(string tagName) Node closest(string selector) Node appendChild(Node node) this insertAdjacentHTML('beforebegin' | 'afterbegin' | 'beforeend' | 'afterend' where, string html) this setAttribute(string key, string value) this setAttributes(Record string, string attrs) this removeAttribute(string key) string getAttribute(string key) this exchangeChild(Node oldNode, Node newNode) this removeChild(Node node) string toString() this set_content(string content) this set_content(Node content) this set_content(Node[] content) this remove() this replaceWith((string | Node)[] ...nodes) ClassList classList HTMLElement clone() HTMLElement getElementById(string id) string text string rawText string tagName string structuredText string structure Node firstChild Node lastChild Node nextSibling HTMLElement nextElementSibling Node previousSibling HTMLElement previousElementSibling string innerHTML string outerHTML string textContent Record attributes [number, number] range } class Node{ <> string toString() Node clone() this remove() number nodeType string innerText string textContent } class ClassList{ add(string c) replace(string c1, string c2) remove(string c) toggle(string c) boolean contains(string c) number length string[] value string toString() } class CommentNode{ CommentNode clone() string toString() } class TextNode{ TextNode clone() string toString() string rawText string trimmedRawText string trimmedText string text boolean isWhitespace } Node --|> HTMLElement Node --|> CommentNode Node --|> TextNode Node ..> ClassList ``` ## HTMLElement Methods ### trimRight() Trim element from right (in block) after seeing pattern in a TextNode. ### removeWhitespace() Remove whitespaces in this sub tree. ### querySelectorAll(selector) Query CSS selector to find matching nodes. Note: Full range of CSS3 selectors supported since v3.0.0. ### querySelector(selector) Query CSS Selector to find matching node. `null` if not found. ### getElementsByTagName(tagName) Get all elements with the specified tagName. Note: Use * for all elements. ### closest(selector) Query closest element by css selector. `null` if not found. ### appendChild(node) Append a child node to childNodes ### insertAdjacentHTML(where, html) Parses the specified text as HTML and inserts the resulting nodes into the DOM tree at a specified position. ### setAttribute(key: string, value: string) Set `value` to `key` attribute. ### setAttributes(attrs: Record) Set attributes of the element. ### removeAttribute(key: string) Remove `key` attribute. ### getAttribute(key: string) Get `key` attribute. `undefined` if not set. ### exchangeChild(oldNode: Node, newNode: Node) Exchanges given child with new child. ### removeChild(node: Node) Remove child node. ### toString() Same as [outerHTML](#htmlelementouterhtml) ### set_content(content: string | Node | Node[]) Set content. **Notice**: Do not set content of the **root** node. ### remove() Remove current element. ### replaceWith(...nodes: (string | Node)[]) Replace current element with other node(s). ### classList #### classList.add Add class name. #### classList.replace(old: string, new: string) Replace class name with another one. #### classList.remove() Remove class name. #### classList.toggle(className: string):void Toggle class. Remove it if it is already included, otherwise add. #### classList.contains(className: string): boolean Returns true if the classname is already in the classList. #### classList.value Get class names. #### clone() Clone a node. #### getElementById(id: string): HTMLElement | null Get element by it's ID. ## HTMLElement Properties ### text Get unescaped text value of current node and its children. Like `innerText`. (slow for the first time) ### rawText Get escaped (as-is) text value of current node and its children. May have `&` in it. (fast) ### tagName Get or Set tag name of HTMLElement. Notice: the returned value would be an uppercase string. ### structuredText Get structured Text. ### structure Get DOM structure. ### firstChild Get first child node. `undefined` if no child. ### lastChild Get last child node. `undefined` if no child ### innerHTML Set or Get innerHTML. ### outerHTML Get outerHTML. ### nextSibling Returns a reference to the next child node of the current element's parent. `null` if not found. ### nextElementSibling Returns a reference to the next child element of the current element's parent. `null` if not found. ### previousSibling Returns a reference to the previous child node of the current element's parent. `null` if not found. ### previousElementSibling Returns a reference to the previous child element of the current element's parent. `null` if not found. ### textContent Get or Set textContent of current element, more efficient than [set_content](#htmlelementset_contentcontent-string--node--node). ### attributes Get all attributes of current element. **Notice: do not try to change the returned value.** ### range Corresponding source code start and end indexes (ie [ 0, 40 ])