Module AbstractController::Helpers::ClassMethods
In: lib/abstract_controller/helpers.rb

Methods

Public Instance methods

Clears up all existing helpers in this class, only keeping the helper with the same name as this class.

The helper class method can take a series of helper module names, a block, or both.

Parameters

  • *args - Module, Symbol, String, :all
  • block - A block defining helper methods

Examples

When the argument is a module it will be included directly in the template class.

  helper FooHelper # => includes FooHelper

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

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 }

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 -%>

Parameters

  • method[, method] - A name or names of a method on the controller to be made available on the view.

When a class is inherited, wrap its helper module in a new module. This ensures that the parent class‘s module can be changed independently of the child class‘s.

[Validate]