Active Model Conversion
Handles default conversions: to_model
, to_key
, to_param
, and to_partial_path.
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 == cm # => true
cm.to_key # => nil
cm.to_param # => nil
cm.to_partial_path # => "contact_messages/contact_message"
Instance Public methods
to_key() Link
Returns an Array
of all key attributes if any of the attributes is set, whether or not the object is persisted. Returns nil
if there are no key attributes.
class Person
include ActiveModel::Conversion
attr_accessor :id
def initialize(id)
@id = id
end
end
person = Person.new(1)
person.to_key # => [1]
to_model() Link
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
.
class Person
include ActiveModel::Conversion
end
person = Person.new
person.to_model == person # => true
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.
to_param() Link
Returns a string
representing the object's key suitable for use in URLs, or nil
if persisted?
is false
.
class Person
include ActiveModel::Conversion
attr_accessor :id
def initialize(id)
@id = id
end
def persisted?
true
end
end
person = Person.new(1)
person.to_param # => "1"
to_partial_path() Link
Returns a string
identifying the path associated with the object. ActionPack uses this to find a suitable partial to represent the object.
class Person
include ActiveModel::Conversion
end
person = Person.new
person.to_partial_path # => "people/person"