1 files changed, 133 insertions, 0 deletions
diff --git a/actionpack/lib/action_controller/new_base/helpers.rb b/actionpack/lib/action_controller/new_base/helpers.rb
new file mode 100644
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+++ b/actionpack/lib/action_controller/new_base/helpers.rb
@@ -0,0 +1,133 @@
+require 'active_support/core_ext/load_error'
+require 'active_support/core_ext/name_error'
+require 'active_support/dependencies'
+
+module ActionController
+  module Helpers
+    extend ActiveSupport::DependencyModule
+
+    depends_on AbstractController::Helpers
+
+    included do
+      # Set the default directory for helpers
+      class_inheritable_accessor :helpers_dir
+      self.helpers_dir = (defined?(RAILS_ROOT) ? "#{RAILS_ROOT}/app/helpers" : "app/helpers")
+    end
+
+    module ClassMethods
+      def inherited(klass)
+        # klass.master_helper_module = Module.new
+        # klass.master_helper_module.__send__ :include, master_helper_module
+        klass.__send__ :default_helper_module!
+        super
+      end
+
+      # The +helper+ class method can take a series of helper module names, a block, or both.
+      #
+      # * <tt>*args</tt>: One or more modules, strings or symbols, or the special symbol <tt>:all</tt>.
+      # * <tt>&block</tt>: A block defining helper methods.
+      # 
+      # ==== Examples
+      # When the argument is a string or symbol, the method will provide the "_helper" suffix, require the file 
+      # and include the module in the template class.  The second form illustrates how to include custom helpers 
+      # when working with namespaced controllers, or other cases where the file containing the helper definition is not
+      # in one of Rails' standard load paths:
+      #   helper :foo             # => requires 'foo_helper' and includes FooHelper
+      #   helper 'resources/foo'  # => requires 'resources/foo_helper' and includes Resources::FooHelper
+      #
+      # When the argument is a module it will be included directly in the template class.
+      #   helper FooHelper # => includes FooHelper
+      #
+      # When the argument is the symbol <tt>:all</tt>, the controller will include all helpers beneath
+      # <tt>ActionController::Base.helpers_dir</tt> (defaults to <tt>app/helpers/**/*.rb</tt> under RAILS_ROOT).
+      #   helper :all
+      #
+      # Additionally, the +helper+ class method can receive and evaluate a block, making the methods defined available 
+      # to the template.
+      #   # One line
+      #   helper { def hello() "Hello, world!" end }
+      #   # Multi-line
+      #   helper do
+      #     def foo(bar) 
+      #       "#{bar} is the very best" 
+      #     end
+      #   end
+      # 
+      # Finally, all the above styles can be mixed together, and the +helper+ method can be invoked with a mix of
+      # +symbols+, +strings+, +modules+ and blocks.
+      #   helper(:three, BlindHelper) { def mice() 'mice' end }
+      #
+      def helper(*args, &block)
+        args.flatten.each do |arg|
+          case arg
+          when :all
+            helper all_application_helpers
+          when String, Symbol
+            file_name  = arg.to_s.underscore + '_helper'
+            class_name = file_name.camelize
+
+            begin
+              require_dependency(file_name)
+            rescue LoadError => load_error
+              requiree = / -- (.*?)(\.rb)?$/.match(load_error.message).to_a[1]
+              if requiree == file_name
+                msg = "Missing helper file helpers/#{file_name}.rb"
+                raise LoadError.new(msg).copy_blame!(load_error)
+              else
+                raise
+              end
+            end
+
+            add_template_helper(class_name.constantize)
+          else
+            # Explcit 'return' here so that the supplied block ( if any ) doesn't get included twice
+            return super
+          end
+        end
+
+        # Evaluate block in template class if given.
+        master_helper_module.module_eval(&block) if block_given?
+      end
+
+      # Declares helper accessors for controller attributes. For example, the
+      # following adds new +name+ and <tt>name=</tt> instance methods to a
+      # controller and makes them available to the view:
+      #   helper_attr :name
+      #   attr_accessor :name
+      def helper_attr(*attrs)
+        attrs.flatten.each { |attr| helper_method(attr, "#{attr}=") }
+      end
+
+      # Provides a proxy to access helpers methods from outside the view.
+      def helpers
+        unless @helper_proxy
+          @helper_proxy = ActionView::Base.new
+          @helper_proxy.extend master_helper_module
+        else
+          @helper_proxy
+        end
+      end
+
+      private
+
+      def default_helper_module!
+        unless name.blank?
+          module_name = name.sub(/Controller$|$/, 'Helper')
+          module_path = module_name.split('::').map { |m| m.underscore }.join('/')
+          require_dependency module_path
+          helper module_name.constantize
+        end
+      rescue MissingSourceFile => e
+        raise unless e.is_missing? module_path
+      rescue NameError => e
+        raise unless e.missing_name? module_name
+      end
+
+      # Extract helper names from files in app/helpers/**/*.rb
+      def all_application_helpers
+        extract = /^#{Regexp.quote(helpers_dir)}\/?(.*)_helper.rb$/
+        Dir["#{helpers_dir}/**/*_helper.rb"].map { |file| file.sub extract, '\1' }
+      end
+    end # ClassMethods
+  end
+end