rails: checking which controller method was called from within the model

Question

Is there a way to check which controller method was called from within the model?

Example: Say the controller create method was called:

def create
     do something
end

Then in the model do something only when create in the controller was called

if create?
      do something
end

Answer 1

I'd imagine you could examine the call stack but this is exactly what models are not for: they should now nothing about the controller.

Examining the stack:

if caller.grep /create/
  # do something
elsif caller.grep /update/
  #do something else
end

Should do the trick.

Answer 2

Just pass a create flag to the model method, or make two different methods in the model and call the appropriate one from the controller. Otherwise you are creating a rather unpleasant dependency between the controller and the model. As you noted, validation methods take a parameter to specify when they are run.

Answer 3

Inside your model you can ask/know if the record you are handling is a new record or not

p = Post.new
p.new_record? => true
p = Post.first
p.new_record? => false

maybe that helps you enough?

Otherwise inside a model you can add callbacks, e.g. a before_create that is only called before a new record is saved. To keep your model lean, and you should have a lot of callbacks, those could be grouped inside an observer.

Hope this helps.