Rubygem: methodize

2010-06-01

2 min

Methodize is a module to read from and write to the keys of a ruby Hash using methods. As simple as this:

require 'methodize/hash'
hash.methodize!

If you don't want to mess with your Hash class, just do this:

require 'methodize'
hash.extend(Methodize)

The advantage of using Methodize is that you can easily access the values of complex or big Hash objects, such as converted JSONs returned from Web Services, RESTful APIs, etc.

Instead of using:

hash["article"].last["info"][:category].first

You can use:

hash.article.last.info.category.first

To install:

gem install methodize

Interested? Let's see more examples

Let's suppose that we have the following hash object:

hash = {
  :article => [
    {
      :title  => "Article 1",
      :author => "John Doe",
      :url    => "http://a.url.com"
    },{
      "title"  => "Article 2",
      "author" => "Foo Bar",
      "url"    => "http://another.url.com"
    },{
      :title  => "Article 3",
      :author => "Biff Tannen",
      :url    => ["http://yet.another.url.com", "http://localhost"],
      :info => {
        :published => "2010-05-31",
        :category  => [:sports, :entertainment]
      }
    }
  ],
  "type" => :text,
  :size  => 3,
  :id    => 123456789
}

You can change the title of the third article using:

hash.article[2].title = "New title"
hash.article[2].title               # => "New title"

Hash public methods that conflicts with keys will be automatically freed:

hash.type                           # => :text
hash.size                           # => 3
hash.id                             # => 123456789

But don't panic, you can still use the Hash methods just as Ruby does for id and send methods by default:

hash.__type__                       # => Hash
hash.__size__                       # => 4 (hash keys count)

Other examples

Writing:

hash.article.last.title = "Article 3"
hash.article[1].info = {
                          :published => "2010-08-31",
                          :category  => [:sports, :entertainment]
                        }
hash.article << {
                   :title  => "A new title",
                   :author => "Marty Mcfly"
                 }
hash.shift  = 12
hash["inspect"] = false
hash.size   = 4

Accessing:

hash.article[2].title               # => "Article 3"
hash.article[1].info.published      # => "2010-08-31"
hash.article.last.author            # => "Marty Mcfly"
hash.shift                          # => 12
hash.inspect                        # => false
hash.__inspect__.class              # => String
hash.size                           # => 4
hash.__size__                       # => 6

You can access the Hash as usual using [] or []=.

Check source code for more details: