AJAX file upload on creation of an object in rails with paperclip

I have a head aching problem that I can't seem to find an easy solution to.

I have a couple of models, each with an image attachment, that belongs to a user. I have made a very nice ajax file upload and image cropping form, but there is a problem. Everything works fine when I am editing objects that is already in the database but when I upload a file as I create a new object it doesn't. The thing is, to be able to upload and save the image, the object already has to be in the database. I have found two possible solutions to this problem but none of 开发者_Go百科them will work properly.

The first one is to create the object in the database in the new action and redirect to edit action. The pros is that it is a very simple fix. The cons is that the objects will show up in the list with previously created ones even if the user canceled or never submitted the form, which is very confusing.

The second possible solution is to lift out the attachment fields of the model to a separate model. On creation I would then only need to create an attachment object. If the user canceled it would leave the attachment orphaned, but that is probably okay as the orphans could be cleared periodically. The problem with this is that I can't find a way to prevent users from hijacking the orphaned images, or any other image for that sake. Unless I cant solve this problem I'm stuck.

I'm all out of ideas and would really need some help on this one.

Thanks, godisemo

EDIT:

I was probably unclear. In my form it is possible to upload an image. The image is uploaded instantly to the server with javascript, before the form is submitted. The reason is that I want to allow the users to crop the image. This is no problem wen working with existing objects but it is when creating new ones, as I tried to explain earlier.

I've never had to have the model already in the db for paperclip to work.

One thing you can try though is the following. I don't know what your model is called but let's say User has an image. Make your new form so that all of your user fields are passed in the params[:user] var, but then make your image upload file separate from params[:user], say params[:my_image].

Then in your controller validate and save the user, then after user.save, attach the image.

I solved the problem now, with a completly different approach. Instead of thinking databases, objects and models I solved it using file system and temporary files. When the image is uploaded it is processed by paperclip, I then move the generated images to a folder where I have control over them.

I based my solution on a really great article which you can find here, http://ryantownsend.co.uk/articles/storing-paperclip-file-uploads-when-validation-fails.html