ruby copy a paperclip attachment from one model to another?

问题

I have two models like this:-

Model 1 - card - contains a representation of data of interest for front page
attachment name = cardimage
Model 2 - user - contains the user
attachment name = avatar

When I create! a new card, I want the avatar from the user model to be copied to the card model as a new cardimage.

Is there a simple one liner for this?

Ruby/Rails/Paperclip

回答1:

This should do the trick, you could use an after_create callback if the models are associated, if not I would recommend doing it in the controller action that creates the card.

instance_of_model_one.cardimage = instance_of_model_two.avatar
instance_of_model_one.save

回答2:

old_avatar = model1.avatar;
model2.avatar.create(attachment: old_avatar.attachment);
model2.save;

It worked for me.

来源：https://stackoverflow.com/questions/14224080/ruby-copy-a-paperclip-attachment-from-one-model-to-another