110 lines
3.1 KiB
Ruby
110 lines
3.1 KiB
Ruby
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module ActiveModel
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# == Active \Model \Conversion
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#
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# Handles default conversions: to_model, to_key, to_param, and to_partial_path.
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#
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# Let's take for example this non-persisted object.
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#
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# class ContactMessage
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# include ActiveModel::Conversion
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#
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# # ContactMessage are never persisted in the DB
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# def persisted?
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# false
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# end
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# end
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#
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# cm = ContactMessage.new
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# cm.to_model == cm # => true
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# cm.to_key # => nil
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# cm.to_param # => nil
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# cm.to_partial_path # => "contact_messages/contact_message"
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module Conversion
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extend ActiveSupport::Concern
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# If your object is already designed to implement all of the \Active \Model
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# you can use the default <tt>:to_model</tt> implementation, which simply
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# returns +self+.
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#
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# class Person
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# include ActiveModel::Conversion
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# end
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#
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# person = Person.new
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# person.to_model == person # => true
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#
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# If your model does not act like an \Active \Model object, then you should
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# define <tt>:to_model</tt> yourself returning a proxy object that wraps
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# your object with \Active \Model compliant methods.
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def to_model
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self
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end
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# Returns an Array of all key attributes if any of the attributes is set, whether or not
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# the object is persisted. Returns +nil+ if there are no key attributes.
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#
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# class Person
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# include ActiveModel::Conversion
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# attr_accessor :id
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#
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# def initialize(id)
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# @id = id
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# end
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# end
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#
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# person = Person.new(1)
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# person.to_key # => [1]
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def to_key
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key = respond_to?(:id) && id
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key ? [key] : nil
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end
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# Returns a +string+ representing the object's key suitable for use in URLs,
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# or +nil+ if <tt>persisted?</tt> is +false+.
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#
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# class Person
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# include ActiveModel::Conversion
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# attr_accessor :id
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#
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# def initialize(id)
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# @id = id
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# end
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#
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# def persisted?
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# true
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# end
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# end
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#
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# person = Person.new(1)
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# person.to_param # => "1"
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def to_param
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(persisted? && key = to_key) ? key.join("-") : nil
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end
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# Returns a +string+ identifying the path associated with the object.
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# ActionPack uses this to find a suitable partial to represent the object.
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#
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# class Person
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# include ActiveModel::Conversion
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# end
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#
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# person = Person.new
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# person.to_partial_path # => "people/person"
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def to_partial_path
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self.class._to_partial_path
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end
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module ClassMethods #:nodoc:
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# Provide a class level cache for #to_partial_path. This is an
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# internal method and should not be accessed directly.
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def _to_partial_path #:nodoc:
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@_to_partial_path ||= begin
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element = ActiveSupport::Inflector.underscore(ActiveSupport::Inflector.demodulize(name))
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collection = ActiveSupport::Inflector.tableize(name)
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"#{collection}/#{element}".freeze
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end
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end
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end
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end
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end
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