After months of work between hunmonk, myself, and chx, we've finalized some substantial progress on multipart forms. A multipart form is a form that is spread across multiple pages (like a wizard), but doesn't truly "submit" until the final page.
Morbus Iff on the drupal development mailing list
That is a cool functionality. While it shows the capability of the forms api to handle multi-page forms via the #pre_render function, which is good, the approach is only the beginning of multi-page form handling.
Some time ago I was writing about a proposed method for resolving application state across multi-page forms. The sceme applies directly.
Unfortunately I haven't had time at all to code anything around it, but let's outline again the process, in fruitless hope that it writes itself.
- keep each form page access data as a separate instance in the session
- make sure there is a mechanism for collecting the garbage from the session
- collect the garbage on 'real submit'
