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 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.
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 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