Webforms rendered twice on one page do not work with same-page conditional actions (affecting Panels in some configs)

I was having this problem too. It turns out that the Panels module calls node_view() twice, which in turn renders the webform_client_form twice. That means that the HTML ID of the form is something like webform-client-form-{id}--2, since drupal_html_id() increments the ID each time. The conditionals JS does not know to also look for forms with these IDs.

Attached is a patch that will apply conditional behaviors to all instances of a webform, regardless of how many times it is rendered. It essentially looks for IDs based on the regex ^webform-client-form-\d+.+$, which should match multiple instances of a webform. This seems to fix the problem, and doesn't seem to introduce a noticeable performance impact.

Re-rolled using relative paths.

Whoops, looks like I messed up that regex a bit. Here's a better one.

Sorry, one more small change to the regex.

Wow, I apologize for totally cluttering this issue with mistakes, but here's a patch that should finally work.

Hi guys, thanks for looking into this issue. The obvious thing for me to ask here is: can you prevent panels from calling node_view() twice? Generating the entire form twice obviously isn't a very efficient way of rendering a page.

Actually maybe this would help with #2022869: Webforms rendered twice on one page do not work with same-page conditional actions, which may make this seem more legitimate. I've marked that issue duplicate. Though generally rendering twice is just a bad thing to have happening.

Retitling for a more generic name. I'm surprised that just fixing the form ID matching would solve this problem, since all the individual form elements are also given different IDs when rendered more than once. At the very least, I would expect this to affect fieldsets hidden by conditionals, which I know work by element ID.

This patch needs work to work correctly with hiding/showing fieldsets and other form elements.

This has been fixed by #2059215: Replace use of IDs to classes on Webform wrappers to avoid duplicate IDs.