In a couple of applications I'm working on I have a need to allow users to upload images which are then tied to something they're creating by filling out a form (a model in my DB). In both cases I'd like them to be able to upload the images on the same page as the form in an ajax-y way. Obviously this leads me to a chicken-and-egg problem - images must belong to a model and refer to its id, but the model has not yet been saved and has no id.
I'm looking for a strategy to remedy this. The only thing I've come up with is to allow users to upload images that initially aren't tied to a model, and then add the model's id to the image's row in the DB when the model is saved. Later, a scheduled reaper comes along looking for images which have no associated model and which were created more than X amount of time in the past, and destroying them. I'm not crazy about the idea of a scheduled reaper (though I'm not entirely allergic to it), and somehow I'd have to store information (probably in the session) that ties the images to the not-yet-finished model until the connection can be made in the DB.
I'm really hoping there's some more obvious (and hopefully simpler) solution I'm overlooking. Any ideas?
Thanks . . .