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
In previous versions of Rails the controller will include a helper which
matches the name of the controller, e.g.,
MyHelper. To return old behavior set
Additional helpers can be specified using the
method in ActionController::Base or any controller
which inherits from it.
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
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
Provides a proxy to access helper methods from outside the view.
# File actionpack/lib/action_controller/metal/helpers.rb, line 117 def helpers @_helper_proxy ||= view_context end