Fast full-featured HTML parsing/serialization toolset for Node. Based on WHATWG HTML5 specification.
To build TestCafé we needed fast and ready for production HTML parser, which will parse HTML as a modern browser's parser.
Existing solutions were either too slow or their output was too inaccurate. So, this is how parse5 was born.
##Install
$ npm install parse5
##Simple usage
var Parser = require('parse5').Parser;
//Instantiate parser
var parser = new Parser();
//Then feed it with an HTML document
var document = parser.parse('<!DOCTYPE html><html><head></head><body>Hi there!</body></html>')
//Now let's parse HTML-snippet
var fragment = parser.parseFragment('<title>Parse5 is fucking awesome!</title><h1>42</h1>');##Is it fast? Check out this benchmark.
Starting benchmark. Fasten your seatbelts...
html5 (https://github.com/aredridel/html5) x 0.18 ops/sec ±5.92% (5 runs sampled)
htmlparser (https://github.com/tautologistics/node-htmlparser/) x 3.83 ops/sec ±42.43% (14 runs sampled)
htmlparser2 (https://github.com/fb55/htmlparser2) x 4.05 ops/sec ±39.27% (15 runs sampled)
parse5 (https://github.com/inikulin/parse5) x 3.04 ops/sec ±51.81% (13 runs sampled)
Fastest is htmlparser2 (https://github.com/fb55/htmlparser2),parse5 (https://github.com/inikulin/parse5)
So, parse5 is as fast as simple specification incompatible parsers and ~15-times(!) faster than the current specification compatible parser available for the node.
##API reference
###Enum: TreeAdapters
Provides built-in tree adapters which can be passed as an optional argument to the Parser and TreeSerializer constructors.
####• TreeAdapters.default Default tree format for parse5.
####• TreeAdapters.htmlparser2 Quite popular htmlparser2 tree format (e.g. used in cheerio and jsdom).
###Class: Parser Provides HTML parsing functionality.
####• Parser.ctor([treeAdapter])
Creates new reusable instance of the Parser. Optional treeAdapter argument specifies resulting tree format. If treeAdapter argument is not specified, default tree adapter will be used.
Example:
var parse5 = require('parse5');
//Instantiate new parser with default tree adapter
var parser1 = new parse5.Parser();
//Instantiate new parser with htmlparser2 tree adapter
var parser2 = new parse5.Parser(parse5.TreeAdapters.htmlparser2);####• Parser.parse(html)
Parses specified html string. Returns document node.
Example:
var document = parser.parse('<!DOCTYPE html><html><head></head><body>Hi there!</body></html>');####• Parser.parseFragment(htmlFragment, [contextElement])
Parses given htmlFragment. Returns documentFragment node. Optional contextElement argument specifies resulting tree format. If contextElement argument is not specified, <div> element will be used.
Example:
var documentFragment = parser.parseFragment('<table></table>');
//Parse html fragment in context of the parsed <table> element
var trFragment = parser.parseFragment('<tr><td>Shake it, baby</td></tr>', documentFragment.childNodes[0]);###Class: TreeSerializer Provides tree-to-HTML serialization functionality.
####• TreeSerializer.ctor([treeAdapter])
Creates new reusable instance of the TreeSerializer. Optional treeAdapter argument specifies input tree format. If treeAdapter argument is not specified, default tree adapter will be used.
Example:
var parse5 = require('parse5');
//Instantiate new serializer with default tree adapter
var serializer1 = new parse5.TreeSerializer();
//Instantiate new serializer with htmlparser2 tree adapter
var serializer2 = new parse5.TreeSerializer(parse5.TreeAdapters.htmlparser2);####• TreeSerializer.serialize(node)
Serializes the given node. Returns HTML string.
Example:
var document = parser.parse('<!DOCTYPE html><html><head></head><body>Hi there!</body></html>');
//Serialize document
var html = serializer.serialize(document);
//Serialize <body> element content
var bodyInnerHtml = serializer.serialize(document.childNodes[0].childNodes[1]);##Testing Test data is adopted from html5lib project. Parser is covered by more than 8000 test cases. To run tests:
$ node test/run_tests.js
##Custom tree adapter You can create a custom tree adapter so parse5 can work with your own DOM-tree implementation. Just pass your adapter implementation to the parser's constructor as an argument:
var Parser = require('parse5').Parser;
var myTreeAdapter = {
//Adapter methods...
};
//Instantiate parser
var parser = new Parser(myTreeAdapter);Sample implementation can be found here.
The custom tree adapter should implement all methods exposed via exports in the sample implementation.
##Questions or suggestions? If you have any questions, please feel free to create an issue here on github.
##Author Ivan Nikulin ([email protected])
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