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 h1
elements 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 €</h1>
<p>Lorem ipsum dolor sit amet ... </p>
<h1>Second article ... </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)
Copyright (c) 2016 M. Peter, http://www.tcs.de
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.