[support] Multipart Form in 6.x

[David Spindler]

I'm trying to figure out the magic of a multipart form.

I'm trying to have a user register his family. So he goes to a form
which has a blank for one person and he keeps clicking "Add another
person" until he has enough blanks for all his family members at which
point he can hit "Save" and it's processed.

Currently I'm doing this in form_validate. If they clicked the Add
Another Person button I called form_set_error('',''). Which returns
them to the form w/o giving them an error. All the form data is still
filled in. If the click the Save button I validate and return and
form_submit() is called which saved the data.

I'm trying to figure out how to pass hidden data so that it can't be
tampered with (For example a family id). Initially I was using a
hidden field with a #value (as opposed to #default_value) under the
assumption that Drupal would validate the field for me and ensure it
was not changed. This doesn't seem to be the case and I'm trying to
figure out another way to keep data with my form w/o having it
tampered with. I tried using a field of #type 'value', but that didn't
seem to get passed back into with the $form_state for the next
iteration. A couple of thoughts I had.

1. Validate the hidden data myself in the validate function comparing
$form_state and $form.
2. Change the way I'm doing this to a more drupal approved way so that
it will validate my hidden data for me? (Is there a flag I can set)
3. Figure out how to get value fields passed  between form submissions.


Thanks, David