Duplicating a record in Rails 3

Question

I have a prescription model in my Rails 3 application. I am trying to work out the best method of allowing records to be duplicated, but allowing the user to \"review\" the

Answer 1

To do this, you're going to have to create a new instance of your Prescription class. "dup" works, but you're assuming it overwrites the existing record. Only methods that end with a bang(!) tend to do that.

Your code should be:

def clone
 @prescription = Prescription.find(params[:id])
 @new_prescription = @prescription.dup
 @new_prescription.save
end

or

def clone
 @prescription = Prescription.find(params[:id]).dup
 @prescription.save
end

This isn't testing for times when the :id isn't found.

Answer 2

If you want the clone action to allow the user to review the duplicate before it is saved (AKA created), then it is almost like the "new" action, except with filled in fields already.

So your clone method could be a modification of your new method:

def new
  @prescription = Prescription.new()
end
def clone
  @prescription = Prescription.find(params[:id]) # find original object
  @prescription = Prescription.new(@prescription.attributes) # initialize duplicate (not saved)
  render :new # render same view as "new", but with @prescription attributes already filled in
end

In the view, they can then create the object.

Answer 3

I was looking for logic to clone an existing record. I had to modify the logic posted by ronalchn slightly because when it tried to execute the second statement of clone I got an mass assignment error because it tried to copy id, created_at, updated_at which are not included in my attr_accessible list. This is how I modified the logic to get it to work in my application using my model:

@old_event = Event.find(params[:id]) # find original object
@event = Event.new
@event.field_1 = @old_event.field_1 (statement for each field in attar_accessible)
render :new # render same view as "new", but with @prescription attributes already filled in