module ActionController::Helpers - actionpack-3.2.22 Documentation

# module ActionController::Helpers

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.

In previous versions of Rails the controller will include a helper whose name matches that of the controller, e.g., `MyController` will automatically include `MyHelper`. 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.

#### Examples¶ ↑

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 `EventController`, 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 Railhaws Training Workshop