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# 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|
extract = /^#{Regexp.quote(_path.to_s)}\/?(.*)_helper.rb$/
names = Dir["#{_path}/**/*_helper.rb"].map { |file| file.sub(extract, '\1'.freeze) }
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
|
