require 'active_support/configurable'
require 'active_support/core_ext/module/anonymous'
module AbstractController
class Error < StandardError; end
class ActionNotFound < StandardError; end
class Base
attr_internal :response_body
attr_internal :action_name
include ActiveSupport::Configurable
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 ||= begin
# All public instance methods of this class, including ancestors
methods = 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
# Clear out AS callback method pollution
methods.reject { |method| method =~ /_one_time_conditions/ }
end
end
# Returns the full controller name, underscored, without the ending Controller.
# For instance, MyApp::MyPostsController would return "my_app/my_posts" for
# controller_name.
#
# ==== Returns
# String
def controller_path
@controller_path ||= name.sub(/Controller$/, '').underscore unless anonymous?
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, *args)
@_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
@_response_body = nil
process_action(action_name, *args)
end
# Delegates to the class' #controller_path
def controller_path
self.class.controller_path
end
def action_methods
self.class.action_methods
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<String>:: 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, *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
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<String>:: 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
