Is there a way to find out what associations a model has? Take these 2 models:
class Comment < ActiveRecord::Base
belongs_to :commentable
end
class Post < ActiveRecord::Base
has_many :comments
belongs_to :user
end
I'm looking for something like:
Post.has_many #=> ['comments', ...]
Post.belongs_to # => ['user']
Comment.belongs_to # => ['commentable']
You're looking for reflect_on_all_associations.
So in short:
Post.reflect_on_all_associations(:has_many)
...will give an array (of object with attributes like name, etc) of all has_many associations.
The following will list all the associations for a particular instance of Post.
#app/models/post.rb
def list_associations
associations = []
User.reflect_on_all_associations.map(&:name).each do |assoc|
association = send assoc
associations << association if association.present?
end
associations
end
