# 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.
### getElementsByTagName(tagName)
Get all elements with the specified tagName.
Note: Use * for all elements.
### closest(selector)
Query closest element by css selector.
### 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.
### 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
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.
### lastChild
Get last child node.
### innerHTML
Set or Get innerHTML.
### outerHTML
Get outerHTML.
### nextSibling
Returns a reference to the next child node of the current element's parent.
### nextElementSibling
Returns a reference to the next child element of the current element's parent.
### previousSibling
Returns a reference to the previous child node of the current element's parent.
### previousElementSibling
Returns a reference to the previous child element of the current element's parent.
### 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 ])
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