Question

I have some code in my application layout view that requires an object to exist in order to work. The object exists on some controllers, but not all.

At first I thought I could use the after_filter on the application_controller to ensure that the object exists. But this didn’t work because the after_filter is only applied after the view is rendered and it is apparently an anti-pattern as well.

What is the best way to ensure that the object always exists, without unnecessarily creating the object on controllers that already create the object.

Answer 1

Say your variable is @foo.

application_helper.rb

def foo
  @foo ||= generate_foo()
end

then from any view, you just call your object by foo and not @foo.