1# htmlparser2 2 3[![NPM version](http://img.shields.io/npm/v/htmlparser2.svg?style=flat)](https://npmjs.org/package/htmlparser2) 4[![Downloads](https://img.shields.io/npm/dm/htmlparser2.svg?style=flat)](https://npmjs.org/package/htmlparser2) 5[![Build Status](https://img.shields.io/github/workflow/status/fb55/htmlparser2/Node.js%20Test?label=tests&style=flat)](https://github.com/fb55/htmlparser2/actions?query=workflow%3A%22Node.js+Test%22) 6[![Coverage](http://img.shields.io/coveralls/fb55/htmlparser2.svg?style=flat)](https://coveralls.io/r/fb55/htmlparser2) 7 8The fast & forgiving HTML/XML parser. 9 10## Installation 11 12 npm install htmlparser2 13 14A live demo of `htmlparser2` is available [here](https://astexplorer.net/#/2AmVrGuGVJ). 15 16## Ecosystem 17 18| Name | Description | 19| ------------------------------------------------------------- | ------------------------------------------------------- | 20| [htmlparser2](https://github.com/fb55/htmlparser2) | Fast & forgiving HTML/XML parser | 21| [domhandler](https://github.com/fb55/domhandler) | Handler for htmlparser2 that turns documents into a DOM | 22| [domutils](https://github.com/fb55/domutils) | Utilities for working with domhandler's DOM | 23| [css-select](https://github.com/fb55/css-select) | CSS selector engine, compatible with domhandler's DOM | 24| [cheerio](https://github.com/cheeriojs/cheerio) | The jQuery API for domhandler's DOM | 25| [dom-serializer](https://github.com/cheeriojs/dom-serializer) | Serializer for domhandler's DOM | 26 27## Usage 28 29`htmlparser2` itself provides a callback interface that allows consumption of documents with minimal allocations. 30For a more ergonomic experience, read [Getting a DOM](#getting-a-dom) below. 31 32```javascript 33const htmlparser2 = require("htmlparser2"); 34const parser = new htmlparser2.Parser({ 35 onopentag(name, attributes) { 36 /* 37 * This fires when a new tag is opened. 38 * 39 * If you don't need an aggregated `attributes` object, 40 * have a look at the `onopentagname` and `onattribute` events. 41 */ 42 if (name === "script" && attributes.type === "text/javascript") { 43 console.log("JS! Hooray!"); 44 } 45 }, 46 ontext(text) { 47 /* 48 * Fires whenever a section of text was processed. 49 * 50 * Note that this can fire at any point within text and you might 51 * have to stich together multiple pieces. 52 */ 53 console.log("-->", text); 54 }, 55 onclosetag(tagname) { 56 /* 57 * Fires when a tag is closed. 58 * 59 * You can rely on this event only firing when you have received an 60 * equivalent opening tag before. Closing tags without corresponding 61 * opening tags will be ignored. 62 */ 63 if (tagname === "script") { 64 console.log("That's it?!"); 65 } 66 }, 67}); 68parser.write( 69 "Xyz <script type='text/javascript'>const foo = '<<bar>>';</ script>" 70); 71parser.end(); 72``` 73 74Output (with multiple text events combined): 75 76``` 77--> Xyz 78JS! Hooray! 79--> const foo = '<<bar>>'; 80That's it?! 81``` 82 83This example only shows three of the possible events. 84Read more about the parser, its events and options in the [wiki](https://github.com/fb55/htmlparser2/wiki/Parser-options). 85 86### Usage with streams 87 88While the `Parser` interface closely resembles Node.js streams, it's not a 100% match. 89Use the `WritableStream` interface to process a streaming input: 90 91```javascript 92const { WritableStream } = require("htmlparser2/lib/WritableStream"); 93const parserStream = new WritableStream({ 94 ontext(text) { 95 console.log("Streaming:", text); 96 }, 97}); 98 99const htmlStream = fs.createReadStream("./my-file.html"); 100htmlStream.pipe(parserStream).on("finish", () => console.log("done")); 101``` 102 103## Getting a DOM 104 105The `DomHandler` produces a DOM (document object model) that can be manipulated using the [`DomUtils`](https://github.com/fb55/DomUtils) helper. 106 107```js 108const htmlparser2 = require("htmlparser2"); 109 110const dom = htmlparser2.parseDocument(); 111``` 112 113The `DomHandler`, while still bundled with this module, was moved to its [own module](https://github.com/fb55/domhandler). 114Have a look at that for further information. 115 116## Parsing RSS/RDF/Atom Feeds 117 118```javascript 119const feed = htmlparser2.parseFeed(content, options); 120``` 121 122Note: While the provided feed handler works for most feeds, 123you might want to use [danmactough/node-feedparser](https://github.com/danmactough/node-feedparser), which is much better tested and actively maintained. 124 125## Performance 126 127After having some artificial benchmarks for some time, **@AndreasMadsen** published his [`htmlparser-benchmark`](https://github.com/AndreasMadsen/htmlparser-benchmark), which benchmarks HTML parses based on real-world websites. 128 129At the time of writing, the latest versions of all supported parsers show the following performance characteristics on [Travis CI](https://travis-ci.org/AndreasMadsen/htmlparser-benchmark/builds/10805007) (please note that Travis doesn't guarantee equal conditions for all tests): 130 131``` 132gumbo-parser : 34.9208 ms/file ± 21.4238 133html-parser : 24.8224 ms/file ± 15.8703 134html5 : 419.597 ms/file ± 264.265 135htmlparser : 60.0722 ms/file ± 384.844 136htmlparser2-dom: 12.0749 ms/file ± 6.49474 137htmlparser2 : 7.49130 ms/file ± 5.74368 138hubbub : 30.4980 ms/file ± 16.4682 139libxmljs : 14.1338 ms/file ± 18.6541 140parse5 : 22.0439 ms/file ± 15.3743 141sax : 49.6513 ms/file ± 26.6032 142``` 143 144## How does this module differ from [node-htmlparser](https://github.com/tautologistics/node-htmlparser)? 145 146This module started as a fork of the `htmlparser` module. 147The main difference is that `htmlparser2` is intended to be used only with node (it runs on other platforms using [browserify](https://github.com/substack/node-browserify)). 148`htmlparser2` was rewritten multiple times and, while it maintains an API that's compatible with `htmlparser` in most cases, the projects don't share any code anymore. 149 150The parser now provides a callback interface inspired by [sax.js](https://github.com/isaacs/sax-js) (originally targeted at [readabilitySAX](https://github.com/fb55/readabilitysax)). 151As a result, old handlers won't work anymore. 152 153The `DefaultHandler` and the `RssHandler` were renamed to clarify their purpose (to `DomHandler` and `FeedHandler`). The old names are still available when requiring `htmlparser2`, your code should work as expected. 154 155## Security contact information 156 157To report a security vulnerability, please use the [Tidelift security contact](https://tidelift.com/security). 158Tidelift will coordinate the fix and disclosure. 159 160## `htmlparser2` for enterprise 161 162Available as part of the Tidelift Subscription 163 164The maintainers of `htmlparser2` and thousands of other packages are working with Tidelift to deliver commercial support and maintenance for the open source dependencies you use to build your applications. Save time, reduce risk, and improve code health, while paying the maintainers of the exact dependencies you use. [Learn more.](https://tidelift.com/subscription/pkg/npm-htmlparser2?utm_source=npm-htmlparser2&utm_medium=referral&utm_campaign=enterprise&utm_term=repo) 165