..today cost me a lot of nerves. I had a simple form and after every page submit, session state value of items were sequentially shifted (after page submit, value of first item become value of second item, value of second item become value of third item and so on...).
Initial form state
Form state after first submit
Form state after third submit
The first time after many years working with APEX I’ve got really pissed off. I’ve tried to isolate the problem, so I’ve deleted most of page items and had a form with only two items, with no processes, branches, dynamic actions...and it happened again – after submit, item values sequentially shifted. Then I’ve tried to create new page and all worked fine.
No matter what, I wanted to discover what’s the problem on the old page. After some time I got to POST request and found a clue. The items were submitted, but the sequence wasn’t right. I’ve got items posted in order from p_t02 to p_t03 and the p_t01 was missing. So I’ve opened FireBug and found it just before </BODY> HTML tag in jQuery UI Dialog. And the answer was here!
On page 0 there was a region (with “missing” item – p_t01) used for jQuery Dialog. After initialization of jQuery dialog, dialogs HTML was generated just before </BODY> HTML tag and the dialog region was pulled from its original position (inside <form id=” wwvFlowForm “> HTML tag) and moved just before the end of HTML body. As you may guess, only items inside <FORM> element are submitted to session state.
Quick solution of this problem was to put regions used for jQuery dialogs as last regions on page, so its items will get the last p_tXX values for name HTML attribute.
You can find test example here.
I hope that this post will help someone someday! :)