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Diffstat (limited to 'actionpack/lib/abstract_controller/base.rb')
| -rw-r--r-- | actionpack/lib/abstract_controller/base.rb | 267 |
1 files changed, 267 insertions, 0 deletions
diff --git a/actionpack/lib/abstract_controller/base.rb b/actionpack/lib/abstract_controller/base.rb new file mode 100644 index 0000000000..bb42f2e119 --- /dev/null +++ b/actionpack/lib/abstract_controller/base.rb @@ -0,0 +1,267 @@ +# frozen_string_literal: true + +require "abstract_controller/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. + # (<tt>ActionController::Metal</tt> 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 + # * <tt>Set</tt> - 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)) + + methods.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 + # * <tt>String</tt> + def controller_path + @controller_path ||= name.sub(/Controller$/, "").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 + # * <tt>self</tt> + 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 <tt>action_methods.include?("foo")</tt> may return + # false and <tt>available_action?("foo")</tt> returns true because + # this method considers actions that are also available + # through other means, for example, implicit render ones. + # + # ==== Parameters + # * <tt>action_name</tt> - 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 + # * <tt>name</tt> - The name of an action to be tested + 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 + # * <tt>action_name</tt> - An action name to find a method name for + # + # ==== Returns + # * <tt>string</tt> - 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 + # * <tt>action_name</tt> - An action name to find a method name for + # + # ==== Returns + # * <tt>string</tt> - The name of the method that handles the action + # * <tt>nil</tt> - 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 |