+ # <% format_time(event.time, :short, "N/A") %> | <%= event.name %> + #
+ # <% end -%> + # + # Finally, assuming we have two event instances, one which has a time and one which does not, + # the output might look like this: + # + # 23 Aug 11:30 | Carolina Railhawks Soccer Match + # N/A | Carolina Railhaws Training Workshop + # + module ClassMethods + # Makes all the (instance) methods in the helper module available to templates rendered through this controller. + # See ActionView::Helpers (link:classes/ActionView/Helpers.html) for more about making your own helper modules + # available to the templates. + def add_template_helper(helper_module) #:nodoc: + master_helper_module.module_eval { include helper_module } + end + + # The +helper+ class method can take a series of helper module names, a block, or both. + # + # * *args: One or more modules, strings or symbols, or the special symbol :all. + # * &block: 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 :all, the controller will include all helpers beneath + # ActionController::Base.helpers_dir (defaults to app/helpers/**/*.rb 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 Module + add_template_helper(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)?$/.match(load_error.message).to_a[1] + if requiree == file_name + msg = "Missing helper file helpers/#{file_name}.rb" + raise LoadError.new(msg).copy_blame!(load_error) + else + raise + end + end + + add_template_helper(class_name.constantize) + else + raise ArgumentError, "helper expects String, Symbol, or Module argument (was: #{args.inspect})" + end + end + + # Evaluate block in template class if given. + master_helper_module.module_eval(&block) if block_given? + end + + # Declare a controller method as a helper. For example, the following + # makes the +current_user+ controller method available to the view: + # class ApplicationController < ActionController::Base + # helper_method :current_user, :logged_in? + # + # def current_user + # @current_user ||= User.find_by_id(session[:user]) + # end + # + # def logged_in? + # current_user != nil + # end + # end + # + # In a view: + # <% if logged_in? -%>Welcome, <%= current_user.name %><% end -%> + def helper_method(*methods) + methods.flatten.each do |method| + master_helper_module.module_eval <<-end_eval + def #{method}(*args, &block) # def current_user(*args, &block) + controller.send(%(#{method}), *args, &block) # controller.send(%(current_user), *args, &block) + end # end + end_eval + end + end + + # Declares helper accessors for controller attributes. For example, the + # following adds new +name+ and name= instance methods to a + # controller and makes them available to the view: + # helper_attr :name + # attr_accessor :name + def helper_attr(*attrs) + attrs.flatten.each { |attr| helper_method(attr, "#{attr}=") } + end + + # Provides a proxy to access helpers methods from outside the view. + def helpers + unless @helper_proxy + @helper_proxy = ActionView::Base.new + @helper_proxy.extend master_helper_module + else + @helper_proxy + end + end + + private + def default_helper_module! + unless name.blank? + module_name = name.sub(/Controller$|$/, 'Helper') + module_path = module_name.split('::').map { |m| m.underscore }.join('/') + require_dependency module_path + helper module_name.constantize + end + rescue MissingSourceFile => e + raise unless e.is_missing? module_path + rescue NameError => e + raise unless e.missing_name? module_name + end + + def inherited_with_helper(child) + inherited_without_helper(child) + + begin + child.master_helper_module = Module.new + child.master_helper_module.__send__ :include, master_helper_module + child.__send__ :default_helper_module! + rescue MissingSourceFile => e + raise unless e.is_missing?("helpers/#{child.controller_path}_helper") + end + end + + # Extract helper names from files in app/helpers/**/*.rb + def all_application_helpers + extract = /^#{Regexp.quote(helpers_dir)}\/?(.*)_helper.rb$/ + Dir["#{helpers_dir}/**/*_helper.rb"].map { |file| file.sub extract, '\1' } + end + end + end +end