Active Model Conversions
Handles default conversions: to_model, to_key and to_param.
Let’s take for example this non persisted object.
class ContactMessage include ActiveModel::Conversion # ContactMessage are never persisted in the DB def persisted? false end end cm = ContactMessage.new cm.to_model == self # => true cm.to_key # => nil cm.to_param # => nil
Methods
Instance Public methods
Returns an Enumerable of all key attributes if any is set, regardless if the object is persisted or not.
Note the default implementation uses persisted? just because all objects in Ruby 1.8.x responds to :id.
If your object is already designed to implement all of the Active Model you can use the default :to_model implementation, which simply returns self.
If your model does not act like an Active Model object, then you should define :to_model yourself returning a proxy object that wraps your object with Active Model compliant methods.