This post originated from an RSS feed registered with Ruby Buzz by rwdaigle. Original Post: What's New in Edge Rails: Create a Hash from XML Feed Title: Ryan's Scraps Feed URL: http://feeds.feedburner.com/RyansScraps Feed Description: Ryan Daigle's various technically inclined rants along w/ the "What's new in Edge Rails" series. Latest Ruby Buzz Posts Latest Ruby Buzz Posts by rwdaigle Latest Posts From Ryan's Scraps

Hash has been extended to provide the ability to create a new hash from an xml string. While this is now used internally by Rails to handle XML requests, it’s also available for use as you see fit.

The basic premise is that XML is mostly a nested set of key => value pairs which is pretty much what a hash is. Population and creation of a hash from an XML structure makes perfect sense and can simplify your use of XML.

What happens when you call Hash.create_from_xml(xml) is that each xml element gets set as a key in the hash and the value of that element is stored as the value in the hash (with typecasting).

Hash.create_from_xml <<EOX
<user>
  <id type="integer">1</id>
  <user-name>ryan</user-name>
</user> 
EOX

{ :user => { :id => 1, :user_name => "ryan" } }

hash = Hash.create_from_xml <<EOX
<users>
  <user>
    <id type="integer">1</id>
    <user-name>ryan</user-name>
  </user> 
  <user>
    <id type="integer">2</id>
    <user-name>doug</user-name>
  </user>
</users>
EOX

hash[:users] #=> { :user => { :id => 1, :user_name => "ryan" },
                    :user => { :id => 2, :user_name => "doug" } }

hash[:users][:user].last #=> { :id => 2, :user_name => "doug" }

All in all just a really easy way to process XML.

tags: rails, rubyonrails, xml