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Module: ActionController::Helpers

Relationships & Source Files
Namespace Children
Modules:
Extension / Inclusion / Inheritance Descendants
Included In:
Base, ::ActionView::TestCase::TestController, Rails::ApplicationController, Rails::InfoController, Rails::MailersController, Rails::WelcomeController
Super Chains via Extension / Inclusion / Inheritance
Class Chain:
Instance Chain:
Defined in: actionpack/lib/action_controller/metal/helpers.rb

Overview

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 #helpers

In previous versions of Rails the controller will include a helper which matches the name of the controller, e.g., MyController will automatically include MyHelper. You can revert to the old behavior with the following:

# config/application.rb
class Application < Rails::Application
  config.action_controller.include_all_helpers = false
end

Additional helpers can be specified using the helper class method in 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="&nbsp;")
    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 EventsController, the format_time 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

::AbstractController::Helpers - Attributes & Methods

Class Attribute Summary

Class Method Summary

::ActiveSupport::Concern - Extended

class_methods

Define class methods from given block.

included

Evaluate given block in context of base class, so that you can write class macros here.

prepended

Evaluate given block in context of base class, so that you can write class macros here.

Instance Method Summary

  • #helpers

    Provides a proxy to access helper methods from outside the view.

::AbstractController::Helpers - Included

DSL Calls

included

[ GitHub ]


62
63
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65
# File 'actionpack/lib/action_controller/metal/helpers.rb', line 62

included do
  class_attribute :helpers_path, default: []
  class_attribute :include_all_helpers, default: true
end

Class Attribute Details

._helper_methods (rw)

[ GitHub ]

  
# File 'actionpack/lib/abstract_controller/helpers.rb', line 10

class_attribute :_helper_methods, default: Array.new

._helper_methods?Boolean (rw)

[ GitHub ]

  
# File 'actionpack/lib/abstract_controller/helpers.rb', line 10

class_attribute :_helper_methods, default: Array.new

.helpers_path (rw)

[ GitHub ]

  
# File 'actionpack/lib/action_controller/metal/helpers.rb', line 59

class << self; attr_accessor :helpers_path; end

Instance Attribute Details

#_helper_methods (rw)

[ GitHub ]

  
# File 'actionpack/lib/abstract_controller/helpers.rb', line 10

class_attribute :_helper_methods, default: Array.new

#_helper_methods?Boolean (rw)

[ GitHub ]

  
# File 'actionpack/lib/abstract_controller/helpers.rb', line 10

class_attribute :_helper_methods, default: Array.new

Instance Method Details

#helpers

Provides a proxy to access helper methods from outside the view.

[ GitHub ]

  
# File 'actionpack/lib/action_controller/metal/helpers.rb', line 128

def helpers
  @_helper_proxy ||= view_context
end