require_relative "error" require "active_support/configurable" require "active_support/descendants_tracker" require "active_support/core_ext/module/anonymous" require "active_support/core_ext/module/attr_internal" module AbstractController # Raised when a non-existing controller action is triggered. class ActionNotFound < StandardError end # AbstractController::Base is a low-level API. Nobody should be # using it directly, and subclasses (like ActionController::Base) are # expected to provide their own +render+ method, since rendering means # different things depending on the context. class Base ## # Returns the body of the HTTP response sent by the controller. attr_internal :response_body ## # Returns the name of the action this controller is processing. attr_internal :action_name ## # Returns the formats that can be processed by the controller. attr_internal :formats include ActiveSupport::Configurable extend ActiveSupport::DescendantsTracker 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) # :nodoc: # Define the abstract ivar on subclasses so that we don't get # uninitialized ivar warnings unless klass.instance_variable_defined?(:@abstract) klass.instance_variable_set(:@abstract, false) end super 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 methods # declared on abstract classes are being removed. # (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 # 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. # # ==== Returns # * Set - A set of all methods that should be considered actions. def action_methods @action_methods ||= begin # All public instance methods of this class, including ancestors methods = (public_instance_methods(true) - # Except for public instance methods of Base and its ancestors internal_methods + # Be sure to include shadowed public instance methods of this class public_instance_methods(false)).uniq.map(&:to_s) methods.to_set end end # action_methods are cached and there is sometimes a need to refresh # them. ::clear_action_methods! allows you to do that, so next time # you run action_methods, they will be recalculated. def clear_action_methods! @action_methods = nil end # Returns the full controller name, underscored, without the ending Controller. # # class MyApp::MyPostsController < AbstractController::Base # # end # # MyApp::MyPostsController.controller_path # => "my_app/my_posts" # # ==== Returns # * String def controller_path @controller_path ||= name.sub(/Controller$/, "".freeze).underscore unless anonymous? end # Refresh the cached action_methods when a new action_method is added. def method_added(name) super clear_action_methods! 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 # AbstractController::ActionNotFound error is raised. # # ==== Returns # * self def process(action, *args) @_action_name = action.to_s unless action_name = _find_action_name(@_action_name) raise ActionNotFound, "The action '#{action}' could not be found for #{self.class.name}" end @_response_body = nil process_action(action_name, *args) end # Delegates to the class' ::controller_path def controller_path self.class.controller_path end # Delegates to the class' ::action_methods def action_methods self.class.action_methods end # Returns true if a method for the action is available and # can be dispatched, false otherwise. # # Notice that action_methods.include?("foo") may return # false and available_action?("foo") returns true because # this method considers actions that are also available # through other means, for example, implicit render ones. # # ==== Parameters # * action_name - The name of an action to be tested def available_action?(action_name) _find_action_name(action_name) end # Tests if a response body is set. Used to determine if the # +process_action+ callback needs to be terminated in # +AbstractController::Callbacks+. def performed? response_body end # Returns true if the given controller is capable of rendering # a path. A subclass of +AbstractController::Base+ # may return false. An Email controller for example does not # support paths, only full URLs. def self.supports_path? true end private # Returns true if the name can be considered an action because # it has a method defined in the controller. # # ==== Parameters # * name - The name of an action to be tested # # :api: private 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. # # Notice that the first argument is the method to be dispatched # which is *not* necessarily the same as the action name. def process_action(method_name, *args) send_action(method_name, *args) 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(*args) action_missing(@_action_name, *args) end # Takes an action name and returns the name of the method that will # handle the action. # # It checks if the action name is valid and returns false otherwise. # # See method_for_action for more information. # # ==== Parameters # * action_name - An action name to find a method name for # # ==== Returns # * string - The name of the method that handles the action # * false - No valid method name could be found. # Raise +AbstractController::ActionNotFound+. def _find_action_name(action_name) _valid_action_name?(action_name) && method_for_action(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 +AbstractController::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. def method_for_action(action_name) if action_method?(action_name) action_name elsif respond_to?(:action_missing, true) "_handle_action_missing" end end # Checks if the action name is valid and returns false otherwise. def _valid_action_name?(action_name) !action_name.to_s.include? File::SEPARATOR end end end