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Diffstat (limited to 'actionpack/lib/action_controller/metal/helpers.rb')
| -rw-r--r-- | actionpack/lib/action_controller/metal/helpers.rb | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/actionpack/lib/action_controller/metal/helpers.rb b/actionpack/lib/action_controller/metal/helpers.rb new file mode 100644 index 0000000000..0faaac1ce4 --- /dev/null +++ b/actionpack/lib/action_controller/metal/helpers.rb @@ -0,0 +1,122 @@ +# frozen_string_literal: true + +module ActionController + # The \Rails framework provides a large number of helpers for working with assets, dates, forms, + # numbers and model objects, to name a few. These helpers are available to all templates + # by default. + # + # In addition to using the standard template helpers provided, creating custom helpers to + # extract complicated logic or reusable functionality is strongly encouraged. By default, each controller + # will include all helpers. These helpers are only accessible on the controller through <tt>#helpers</tt> + # + # In previous versions of \Rails the controller will include a helper which + # matches the name of the controller, e.g., <tt>MyController</tt> will automatically + # include <tt>MyHelper</tt>. To return old behavior set +config.action_controller.include_all_helpers+ to +false+. + # + # Additional helpers can be specified using the +helper+ class method in ActionController::Base or any + # controller which inherits from it. + # + # The +to_s+ method from the \Time class can be wrapped in a helper method to display a custom message if + # a \Time object is blank: + # + # module FormattedTimeHelper + # def format_time(time, format=:long, blank_message=" ") + # time.blank? ? blank_message : time.to_s(format) + # end + # end + # + # FormattedTimeHelper can now be included in a controller, using the +helper+ class method: + # + # class EventsController < ActionController::Base + # helper FormattedTimeHelper + # def index + # @events = Event.all + # end + # end + # + # Then, in any view rendered by <tt>EventController</tt>, the <tt>format_time</tt> method can be called: + # + # <% @events.each do |event| -%> + # <p> + # <%= format_time(event.time, :short, "N/A") %> | <%= event.name %> + # </p> + # <% 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 Railhawks Training Workshop + # + module Helpers + extend ActiveSupport::Concern + + class << self; attr_accessor :helpers_path; end + include AbstractController::Helpers + + included do + class_attribute :helpers_path, default: [] + class_attribute :include_all_helpers, default: true + end + + module ClassMethods + # 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: + # attr_accessor :name + # helper_attr :name + # + # ==== Parameters + # * <tt>attrs</tt> - Names of attributes to be converted into helpers. + def helper_attr(*attrs) + attrs.flatten.each { |attr| helper_method(attr, "#{attr}=") } + end + + # Provides a proxy to access helper methods from outside the view. + def helpers + @helper_proxy ||= begin + proxy = ActionView::Base.new + proxy.config = config.inheritable_copy + proxy.extend(_helpers) + end + end + + # Overwrite modules_for_helpers to accept :all as argument, which loads + # all helpers in helpers_path. + # + # ==== Parameters + # * <tt>args</tt> - A list of helpers + # + # ==== Returns + # * <tt>array</tt> - A normalized list of modules for the list of helpers provided. + def modules_for_helpers(args) + args += all_application_helpers if args.delete(:all) + super(args) + end + + # Returns a list of helper names in a given path. + # + # ActionController::Base.all_helpers_from_path 'app/helpers' + # # => ["application", "chart", "rubygems"] + def all_helpers_from_path(path) + helpers = Array(path).flat_map do |_path| + names = Dir["#{_path}/**/*_helper.rb"].map { |file| file[_path.to_s.size + 1..-"_helper.rb".size - 1] } + names.sort! + end + helpers.uniq! + helpers + end + + private + # Extract helper names from files in <tt>app/helpers/**/*_helper.rb</tt> + def all_application_helpers + all_helpers_from_path(helpers_path) + end + end + + # Provides a proxy to access helper methods from outside the view. + def helpers + @_helper_proxy ||= view_context + end + end +end |