# README.rdoc

Path: | README.rdoc
Last Update: | Tue Jun 05 20:39:04 +0000 2012

# Nokogiri

- nokogiri.org
- github.com/tenderlove/nokogiri/wikis
- github.com/tenderlove/nokogiri/tree/master
- groups.google.com/group/nokogiri-talk
- github.com/tenderlove/nokogiri/issues

## DESCRIPTION:

Nokogiri (鋸) is an HTML, XML, SAX, and Reader parser. Among Nokogiri‘s many features is the ability to search documents via XPath or CSS3 selectors.

XML is like violence - if it doesn’t solve your problems, you are not using enough of it.

## FEATURES:

- XPath support for document searching
- CSS3 selector support for document searching
- XML/HTML builder

Nokogiri parses and searches XML/HTML very quickly, and also has correctly implemented CSS3 selector support as well as XPath support.

## SUPPORT:

The Nokogiri mailing list is available here:

      * http://groups.google.com/group/nokogiri-talk

The bug tracker is available here:

      * http://github.com/tenderlove/nokogiri/issues

The IRC channel is nokogiri on freenode.

## SYNOPSIS:

      require 'nokogiri'
      require 'open-uri'

      # Get a Nokogiri::HTML:Document for the page we’re interested in...

      doc = Nokogiri::HTML(open('http://www.google.com/search?q=tenderlove'))

      # Do funky things with it using Nokogiri::XML::Node methods...

      ####
      # Search for nodes by css
      doc.css('h3.r a.l').each do |link|
        puts link.content
      end

      ####
      # Search for nodes by xpath
      doc.xpath('//h3/a[@class="l"]').each do |link|
        puts link.content
      end

      ####
      # Or mix and match.
      doc.search('h3.r a.l', '//h3/a[@class="l"]').each do |link|
        puts link.content
      end

## REQUIREMENTS:

- ruby 1.8 or 1.9
- libxml2
- libxml2-dev
- libxslt
- libxslt-dev

## ENCODING:

Strings are always stored as UTF-8 internally. Methods that return text values will always return UTF-8 encoded strings. Methods that return XML (like to_xml, to_html and inner_html) will return a string encoded like the source document.

WARNING

Some documents declare one particular encoding, but use a different one. So, which encoding should the parser choose?

Remember that data is just a stream of bytes. Only us humans add meaning to that stream. Any particular set of bytes could be valid characters in multiple encodings, so detecting encoding with 100% accuracy is not possible. libxml2 does its best, but it can‘t be right 100% of the time.

If you want Nokogiri to handle the document encoding properly, your best bet is to explicitly set the encoding. Here is an example of explicitly setting the encoding to EUC-JP on the parser:

        doc = Nokogiri.XML('<foo><bar /><foo>', nil, 'EUC-JP')

## INSTALL:

- sudo gem install nokogiri

### Binary packages

Binary packages are available for:

- SuSE
- Fedora

## DEVELOPMENT:

### Developing on C Ruby (MRI)

Developing Nokogiri requires racc and rexical to generate the parser and tokenizer. To start development, make sure you have `libxml2` and `libxslt` installed.

Then install hoe and rake-compiler:

        $ gem install hoe rake-compiler racc rexical minitest

Then run rake:

        $ rake

### Developing on JRuby

Currently, development with JRuby depends on C Ruby being installed. With normal C Ruby, install racc and rexical:

        $ gem install racc rexical

Make sure hoe and rake compiler are installed with JRuby:

        $ jgem install hoe rake-compiler

Then run rake:

        $ jruby -S rake

## LICENSE:

(The MIT License)

Copyright (c) 2008 - 2010:

- Aaron Patterson
- Mike Dalessio
- Charles Nutter
- Sergio Arbeo
- Patrick Mahoney
- Yoko Harada

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.

[Validate]