获取回调ActiveRecord Rails的当前名称

Question

On model User have after_create :apply_role and after_update :apply_role , and I want to get current name of callback on apply_role method.

something like :

def apply_role
 if callback_name == 'after_create'
    # other stuff here
 else
    # other stuff here
 end
end

I know I can set different method between after_create and after_update , but in my case method on after_create and after_update not different except one line, so I want refactor my code and I just need one method for multiple callback.

How can I do that?

Answer 1

Try following, I have described the changes in comments in the code itself.

def User < ActiveRecord::Base
  after_save :apply_role # this will gets called in case of create as well as update

  def apply_role
    if id_changed?
      # code to handle newly created record
    else
      # code to handle updated record
    end
  end
end

Answer 2

To answer your question, you'd use id_changed? to determine if you are in a after_save ( true ) or after_update ( false ) callback.

Like this:

def apply_role
  if id_changed?
    # created
  else
    # updated
  end
end

Though that is generally not the way it is done. It would be better to split those into separate methods and use the proper method with its corresponding callback.

Something like this:

after_create :apply_role
after_update :update_role

def apply_role
  # do stuff
end

def update_role
  # do other stuff
end