Hash and Objects

It’s a common task to simulate objects from hashes, but one has to remember using hash access format in order to access it. Hashi helps you by allowing direct access to its content:


	hash = { :team => {:players => [{:name=>"guilherme silveira"},{:name=>"jose donizetti"}]}}
	object = Hashi.to_object(hash)
	puts object.team.players[0].name

Why would I use Hashi?

The reality without Hashi


	hash = { :team => {:players => [{:name=>"guilherme silveira"},{:name=>"jose donizetti"}]}}
	puts hash[:team][:players][0][:name] # his name

Although the Ruby language provides an easy way to access hashes, it becomes easier if you use Rails and has created an ActiveRecord for your representation:

The reality without Hashi, within Rails


	class Team < ActiveRecord::Base
		has_many :players
	end
	class Player < ActiveRecord::Base
		# create a migration with field name:string
	end
	hash = { :team => {:players => [{:name=>"guilherme silveira"},{:name=>"jose donizetti"}]}}
	puts hash[:player][0][:name] # his name

How does it compare to Hashie?

Hashi actually does not create your attributes, instead it deals with method_missing invocations to simulate those properties, never creating a copy of your hash.

More info

You can access the original hash (updated if you have made any changes) by one of those two ways:


	hash = { :team => {:players => [{:name=>"guilherme silveira"},{:name=>"jose donizetti"}]}}
	object = Hashi.to_object(hash)
	object.team.players[0].name = 'jose donizetti'
	
	# the original hash was modified!
	puts hash
	
	# you can extract the original hash if you wish
	puts object.hash

Installing

Ruby

gem install gemcutter gem tumble gem install hashi

Rails

Just add in your environment.rb the following line:


config.gem "hashi", :source => "http://gemcutter.org"

And then execute:

rake gems:install

or, if you prefer to install it as a plugin:

script/plugin install git://github.com/caelum/hashi.git

Help

If you are looking for or want to help, let us know at the mailing list:

http://groups.google.com/group/hashi-ruby

Team

Hashi was created and is maintained within Caelum:http://www.caelum.com.br by

Projetct Founder

Guilherme Silveira – twitter:http://www.twitter.com/guilhermecaelum http://guilhermesilveira.wordpress.com

Active Commiters

Guilherme Silveira
Jose Donizetti

Sources

You can see its source code at: github

License

Licensed under the Apache License, Version 2.0 (the “License”);
you may not use this file except in compliance with the License.
You may obtain a copy of the License at *
http://www.apache.org/licenses/LICENSE-2.0 *
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an “AS IS” BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License. */