module AbstractController class Base attr_internal :response_body attr_internal :action_name class << self attr_reader :abstract alias_method :abstract?, :abstract # Define a controller as abstract. See internal_methods for more # details. def abstract! @abstract = true end def inherited(klass) ::AbstractController::Base.descendants << klass.to_s super end # A list of all descendents of AbstractController::Base. This is # useful for initializers which need to add behavior to all controllers. def descendants @descendants ||= [] end # A list of all internal methods for a controller. This finds the first # abstract superclass of a controller, and gets a list of all public # instance methods on that abstract class. Public instance methods of # a controller would normally be considered action methods, so we # are removing those methods on classes declared as abstract # (ActionController::Metal and ActionController::Base are defined # as abstract) def internal_methods controller = self controller = controller.superclass until controller.abstract? controller.public_instance_methods(true) end # The list of hidden actions to an empty Array. Defaults to an # empty Array. This can be modified by other modules or subclasses # to specify particular actions as hidden. # # ==== Returns # Array[String]:: An array of method names that should not be # considered actions. def hidden_actions [] end # A list of method names that should be considered actions. This # includes all public instance methods on a controller, less # any internal methods (see #internal_methods), adding back in # any methods that are internal, but still exist on the class # itself. Finally, #hidden_actions are removed. # # ==== Returns # Array[String]:: A list of all methods that should be considered # actions. def action_methods @action_methods ||= # All public instance methods of this class, including ancestors public_instance_methods(true).map { |m| m.to_s }.to_set - # Except for public instance methods of Base and its ancestors internal_methods.map { |m| m.to_s } + # Be sure to include shadowed public instance methods of this class public_instance_methods(false).map { |m| m.to_s } - # And always exclude explicitly hidden actions hidden_actions end end abstract! # Calls the action going through the entire action dispatch stack. # # The actual method that is called is determined by calling # #method_for_action. If no method can handle the action, then an # ActionNotFound error is raised. # # ==== Returns # self def process(action) @_action_name = action_name = action.to_s unless action_name = method_for_action(action_name) raise ActionNotFound, "The action '#{action}' could not be found" end process_action(action_name) self end private # Returns true if the name can be considered an action. This can # be overridden in subclasses to modify the semantics of what # can be considered an action. # # ==== Parameters # name:: The name of an action to be tested # # ==== Returns # TrueClass, FalseClass def action_method?(name) self.class.action_methods.include?(name) end # Call the action. Override this in a subclass to modify the # behavior around processing an action. This, and not #process, # is the intended way to override action dispatching. def process_action(method_name) send_action(method_name) end # Actually call the method associated with the action. Override # this method if you wish to change how action methods are called, # not to add additional behavior around it. For example, you would # override #send_action if you want to inject arguments into the # method. alias send_action send # If the action name was not found, but a method called "action_missing" # was found, #method_for_action will return "_handle_action_missing". # This method calls #action_missing with the current action name. def _handle_action_missing action_missing(@_action_name) end # Takes an action name and returns the name of the method that will # handle the action. In normal cases, this method returns the same # name as it receives. By default, if #method_for_action receives # a name that is not an action, it will look for an #action_missing # method and return "_handle_action_missing" if one is found. # # Subclasses may override this method to add additional conditions # that should be considered an action. For instance, an HTTP controller # with a template matching the action name is considered to exist. # # If you override this method to handle additional cases, you may # also provide a method (like _handle_method_missing) to handle # the case. # # If none of these conditions are true, and method_for_action # returns nil, an ActionNotFound exception will be raised. # # ==== Parameters # action_name:: An action name to find a method name for # # ==== Returns # String:: The name of the method that handles the action # nil:: No method name could be found. Raise ActionNotFound. def method_for_action(action_name) if action_method?(action_name) then action_name elsif respond_to?(:action_missing, true) then "_handle_action_missing" end end end end