call an class method given an instance in ruby

Question

I'm using rails ActiveModel, I defined 2 methods like this:

def find_existing_task(task)
  existing_one = Task.find(task.id)
end
def find_existing_person(person)
  existing_one = People.find(person.id)
end

But I think I need a more generic method like this:

def find_existing(any_active_model_instance_with_id)
  existing_one = ActiveModelClass.find(any_active_model_instance_with_id.id)
end

But I don't know how to call the class method given an instance, in above, given task, I can call Task.find without specifing class name "Task"

Any solution? thanks!

Answer 1

You can do it with the following code

def find_existing(some_model)
  existing_one = some_model.class.find(some_model.id)
end