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Diffstat (limited to 'actionpack/lib/abstract_controller/helpers.rb')
-rw-r--r-- | actionpack/lib/abstract_controller/helpers.rb | 82 |
1 files changed, 82 insertions, 0 deletions
diff --git a/actionpack/lib/abstract_controller/helpers.rb b/actionpack/lib/abstract_controller/helpers.rb new file mode 100644 index 0000000000..5efa37fde3 --- /dev/null +++ b/actionpack/lib/abstract_controller/helpers.rb @@ -0,0 +1,82 @@ +module AbstractController + module Helpers + extend ActiveSupport::Concern + + include Renderer + + included do + extlib_inheritable_accessor(:_helpers) { Module.new } + end + + module ClassMethods + # When a class is inherited, wrap its helper module in a new module. + # This ensures that the parent class's module can be changed + # independently of the child class's. + def inherited(klass) + helpers = _helpers + klass._helpers = Module.new { include helpers } + + super + end + + # Declare a controller method as a helper. For example, the following + # makes the +current_user+ controller method available to the view: + # class ApplicationController < ActionController::Base + # helper_method :current_user, :logged_in? + # + # def current_user + # @current_user ||= User.find_by_id(session[:user]) + # end + # + # def logged_in? + # current_user != nil + # end + # end + # + # In a view: + # <% if logged_in? -%>Welcome, <%= current_user.name %><% end -%> + # + # ==== Parameters + # meths<Array[#to_s]>:: The name of a method on the controller + # to be made available on the view. + def helper_method(*meths) + meths.flatten.each do |meth| + _helpers.class_eval <<-ruby_eval, __FILE__, __LINE__ + 1 + def #{meth}(*args, &blk) + controller.send(%(#{meth}), *args, &blk) + end + ruby_eval + end + end + + # Make a number of helper modules part of this class' default + # helpers. + # + # ==== Parameters + # *args<Array[Module]>:: Modules to be included + # block<Block>:: Evalulate the block in the context + # of the helper module. Any methods defined in the block + # will be helpers. + def helper(*args, &block) + args.flatten.each do |arg| + case arg + when Module + add_template_helper(arg) + end + end + _helpers.module_eval(&block) if block_given? + end + + private + # Makes all the (instance) methods in the helper module available to templates + # rendered through this controller. + # + # ==== Parameters + # mod<Module>:: The module to include into the current helper module + # for the class + def add_template_helper(mod) + _helpers.module_eval { include mod } + end + end + end +end |