method

method_missing

v3.0.9 - Show latest stable - Class: ActiveRecord::Base

method_missing(method_id, *arguments, &block)

private

Enables dynamic finders like User.find_by_user_name(user_name) and <tt>User.scoped_by_user_name(user_name). Refer to Dynamic attribute-based finders section at the top of this file for more detailed information.

It’s even possible to use all the additional parameters to find. For example, the full interface for find_all_by_amount is actually find_all_by_amount(amount, options).

Each dynamic finder using scoped_by_* is also defined in the class after it is first invoked, so that future attempts to use it do not run through method_missing.

# File activerecord/lib/active_record/base.rb, line 986
        def method_missing(method_id, *arguments, &block)
          if match = DynamicFinderMatch.match(method_id)
            attribute_names = match.attribute_names
            super unless all_attributes_exists?(attribute_names)
            if match.finder?
              options = arguments.extract_options!
              relation = options.any? ? construct_finder_arel(options, current_scoped_methods) : scoped
              relation.send :find_by_attributes, match, attribute_names, *arguments
            elsif match.instantiator?
              scoped.send :find_or_instantiator_by_attributes, match, attribute_names, *arguments, &block
            end
          elsif match = DynamicScopeMatch.match(method_id)
            attribute_names = match.attribute_names
            super unless all_attributes_exists?(attribute_names)
            if match.scope?
              self.class_eval                 def self.#{method_id}(*args)                        # def self.scoped_by_user_name_and_password(*args)                  options = args.extract_options!                   #   options = args.extract_options!                  attributes = construct_attributes_from_arguments( #   attributes = construct_attributes_from_arguments(                    [:#{attribute_names.join(',:')}], args          #     [:user_name, :password], args                  )                                                 #   )                                                                    #                  scoped(:conditions => attributes)                 #   scoped(:conditions => attributes)                end                                                 # end, __FILE__, __LINE__ + 1
              send(method_id, *arguments)
            end
          else
            super
          end
        end

method_missing

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