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 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 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
- H
Attributes
[RW] | helpers_path |