polymorphic_identity
polymorphic_identity
dynamically generates aliases for polymorphic associations based on the class names of those associations.
Resources
API
Bugs
Development
Source
-
git://github.com/pluginaweek/polymorphic_identity.git
Description
Polymorphic associations are not very descriptive when it comes to easily knowing the type of model your interacting with. For example, a typical polymorphic assocation looks like the following:
class Tag < ActiveRecord::Base
belongs_to :taggable, :polymorphic => true
end
When getting the taggable record, you would normally have to call tag.taggable
. However, if you know that the taggable record is just an instance of the Article model, then it would feel more comfortable if you could just call tag.article
. polymoprhic_identity makes this possible by dynamically checking the name of the polymorphic record’s class and creating methods that allow you to access the polymorphic association based on that class name.
Usage
Example
class Comment < ActiveRecord::Base
belongs_to :commentable, :polymorphic => true
belongs_to :commenter, :polymorphic => true
end
class Article < ActiveRecord::Base
has_many :comments, :as => :commentable
end
class User < ActiveRecord::Base
has_many :comments, :as => :commenter
end
c = Comment.find(1) # => #<Tag id: 1, commentable_id: 1, commentable_type: "Article", commenter_id: 1, commenter_type: "User"}>
c.commentable # => #<Article id: 1>
c.article # => #<Article id: 1>
c.commenter # => #<User id: 1>
c.user # => #<User id: 1>
Testing
Before you can run any tests, the following gem must be installed:
To run against a specific version of Rails:
rake test RAILS_FRAMEWORK_ROOT=/path/to/rails
Dependencies
-
Rails 2.0 or later