rails/activemodel/lib/active_model/conversion.rb
Grant Hutchins & Peter Jaros bf812074fd Let ActiveModel instances define partial paths.
Deprecate ActiveModel::Name#partial_path. Now you
should call #to_path directly on ActiveModel
instances.
2011-07-25 16:05:24 -04:00

72 lines
2.1 KiB
Ruby

require 'active_support/concern'
require 'active_support/inflector'
module ActiveModel
# == Active Model Conversions
#
# Handles default conversions: to_model, to_key, to_param, and to_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 == self # => true
# cm.to_key # => nil
# cm.to_param # => nil
# cm.to_path # => "contact_messages/contact_message"
#
module Conversion
extend ActiveSupport::Concern
# If your object is already designed to implement all of the Active Model
# you can use the default <tt>:to_model</tt> implementation, which simply
# returns self.
#
# If your model does not act like an Active Model object, then you should
# define <tt>:to_model</tt> yourself returning a proxy object that wraps
# your object with Active Model compliant methods.
def to_model
self
end
# 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 <tt>:id</tt>.
def to_key
persisted? ? [id] : nil
end
# Returns a string representing the object's key suitable for use in URLs,
# or nil if <tt>persisted?</tt> is false.
def to_param
persisted? ? to_key.join('-') : nil
end
# Returns a string identifying the path associated with the object.
# ActionPack uses this to find a suitable partial to represent the object.
def to_path
self.class.to_path
end
module ClassMethods
def to_path
@_to_path ||= begin
element = ActiveSupport::Inflector.underscore(ActiveSupport::Inflector.demodulize(self))
collection = ActiveSupport::Inflector.tableize(self)
"#{collection}/#{element}".freeze
end
end
end
end
end