Html-extractor NPM

html-extractor

Extract meta-data from a html string. It extracts the body, title, meta-tags and first headlines to a object to push them to a search indexer like elastic-search

Install

	npm install html-extractor

Initialize

var Extrator = require("html-extractor");
var myExtrator = new Extrator();

`new Extrator( debug )`

arguments

debug : ( Boolean optional: default = false )
Output the parsing time

Methods

Extrator.extract( html, reduced, cb )

Call .extract() to get the data of an html string.
HTML entities will be decoded.

arguments:

html : ( String required )
The html string to process
reduced : ( Object optional )
A object to reduce the content of body to a specific site content. It is not possible to reduce to a tag without a attribute filter. - reduced.tag : ( String required if reduced is set )
The tag name of the html element to reduce to - reduced.attr : ( String required if reduced is set )
The attribute of the html element to reduce to - reduced.val : ( String required if reduced is set )
The attribute value of the html element to reduce to - reduced.list : ( Boobean default = false )
Return every found reduced block as an array within body.
cb : ( Function required )
The callback function

callback arguments:

error : ( Error )
Error information. If no error occoured this will be null
data : ( Object )
The extraction result - data.body : ( String|Array )
The whole body content or the content within the configured reduced element. There will be just the text content without html tags/attributes and without the content in script tags. If the reduced feature is used and reduced.list = true the body will be an array of all found reduced blocks.
- data.h1 : ( Array )
An array containing all h1 text contents. Including the h1elements outside the configured reduced element - data.meta : ( Object )
A Object of all found meta tags with the syntax <meta content="" name="">. Other meta tags will be ignored. - data.meta.charset : ( String optional )
If a metatag with the charset setting like <meta charset="utf-8" > is defined it will be returned under data.meta.charset - data.meta.title : ( String default = "" )
If tilte tag is defined it will be returned under data.meta.title. Otherwise the key will contain an empty string - data.meta.description : ( String default = "" )
If a metatag with the name description is defined it will be returned under data.meta.description. Otherwise the key will contain an empty string - data.meta.keywords : ( Array default = [] )
If a metatag with the name keywords is defined it will be returned as trimmed array of strings under data.meta.keywords. Otherwise the key will contain an empty string

Examples

simple

This is a simple example to extarct the content of a html document

var Extrator = require("html-extractor");
var myExtrator = new Extrator();

var html = `
<html> 
	<head>
		<title>Testpage</title>
	</head>
	<body>
		<h1>Header 1</h1>
		<p>Content</p>
	</body>
</html>
`

myExtrator.extract( html, function( err, data ){
	if( err ){
		throw( err )
    } else {
		console.log( data );
		// {
		// 	meta: {
		// 		title: 'Testpage',
		//		description: '',
		//		keywords: []
		//	},
		//	body: ' Header 1 Content ',
		//	h1: [ 'Header 1' ]
		// }
    }
});

see test/readme_example_simple or run in Tonic

advanced

This is a advanced example to show the usage of the reducing. With the reduce feature it is possible to reduce the body content to the content of a specific html element.

var Extrator = require("html-extractor");
var myExtrator = new Extrator();

var html = `
<html>
	<head>
		<title>Super page</title>
		<meta content="X, Y, Z" name="keywords">
		<meta content="Look at this super page" name="description">
		<meta content="Super pageCMS" name="generator">
	</head>
	<body>
		<div id="head">
			<h1>My super page<sup>2</sup></h1>
		</div> 
		<ul id="menu">
			<li>Home</li>
			<li>First</li>
			<li>Second</li>
		</ul>
		<div id="content">
			<h1>First article &euro;</h1>
			<p>Lorem ipsum dolor sit amet ... </p>
			<h1>Second article&nbsp;&nbsp;...&nbsp;&nbsp;</h1>
			<p>Aenean commodo ligula eget dolor.</p>
			<script>
				var superVar = [ 3,2,1 ]
			</script>
		</div>
		<section class="abc">
			<h3>ABC 1</h3>
			<p>Lorem ipsum dolor sit amet ... </p>
		</section>
		<section class="xyz">
			<h3>XYZ 1</h3>
			<p>Lorem ipsum dolor sit amet ... </p>
		</section>
		<section class="abc">
			<h3>ABC 2</h3>
			<p>Lorem ipsum dolor sit amet ... </p>
		</section>
		<div id="footer">
			Copyright 2013
		</div>
	</body>
</html>
`

var reduceTo = {
	tag: "div",
	attr: "id",
	val: "content"
}

myExtrator.extract( html, reduceTo, function( err, data ){
	if( err ){
		throw( err )
	} else {
		console.log( "String", data );
		//{
		//	meta: {
		//		title: 'Super page',
		//		description: 'Look at this super page',
		//		keywords: ['X', 'Y', 'Z'],
		//		generator: 'Super pageCMS'
		//	},
		//	body: 'First article € Lorem ipsum dolor sit amet ... Second article  ... Aenean commodo ligula eget dolor. ',
		//	h1: ['My super page2', 'First article €', 'Second article  ...']
		//}
	}
});

var reduceToList = {
	tag: "div",
	attr: "id",
	val: "content",
	list: true
}; 

myExtrator.extract( html, reduceToList, function( err, data ){
	if( err ){
		throw( err )
	} else {
		console.log( "List", data );
		//{
		//	meta: {
		//		title: 'Super page',
		//		description: 'Look at this super page',
		//		keywords: ['X', 'Y', 'Z'],
		//		generator: 'Super pageCMS'
		//	},
		//	body: [
		//		'ABC 1 Lorem ipsum dolor sit amet ... ',
		//		'ABC 2 Lorem ipsum dolor sit amet ... '
		//	],
		//	h1: ['My super page2', 'First article', 'Second article']
		//}
	}
});

see test/readme_example_advanced or run in Tonic

Work in progress

html-extractor is work in progress. Your ideas, suggestions etc. are very welcome.

Release History

Version	Date	Description
0.2.2	2016-07-1	Fixed trimming when `reduced.list` is active #3. Thanks to Javier Castro
0.2.1	2016-06-30	Fixed handling of html entities #1. Thanks to Javier Castro
0.2.0	2016-06-20	Added option to return reduced elements as list; Fixed reduced value check for classes; Optimized dev env.
0.1.4	-	Updated and pinned dependencies and optimized tests
0.1.3	-	Fixed extraction to remove style-tag content
0.1.2	-	Updated documentation
0.1.1	-	Added raw documentation; Fixed `travis.yml`
0.1.0	-	Initial version

License

(The MIT License)

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.