iFrame Theme not sticking on form submissions

Let me follow up first by saying that I have read the README file and followed it to the letter. I tried ripping out DFF 2-rc2 and upgrading to 3-dev which led to it's own problems so I went back to 2-rc2.

I have modified the code in includes/theme.inc to include the code suggested in #187868: Facebook not using fbml theme, comment #11 which led to these observations:
The main page in FB shows the following Locations/Referrer pattern:
Location - http://flixfling.com/drupal_dev/?fb_sig_in_iframe=1&fb_sig_iframe_key=0a8005f5594bd67041f88c6196192646&fb_sig_locale=en_US&fb_sig_in_new_facebook=1&fb_sig_time=1276093265.2018&fb_sig_added=1&fb_sig_profile_update_time=1274971926&fb_sig_expires=1276099200&fb_sig_user=100001144279508&fb_sig_session_key=2.LUla0LSemn0WISnLEEvxAA__.3600.1276099200-100001144279508&fb_sig_ss=gYb0NNI2QTFuLUSiUkAfow__&fb_sig_cookie_sig=e0ead4f64f9dd3327c1d60f48cd23102&fb_sig_ext_perms=auto_publish_recent_activity&fb_sig_country=us&fb_sig_api_key=093ae4c6af0fbc23e84d56838a82155d&fb_sig_app_id=112721765427901&fb_sig=e2f613b45dabfe47222e825db54866b8
Referrer - http://apps.facebook.com/flixfling/

Clicking on any non-form link shows the same pattern:
Location - http://flixfling.com/drupal_dev/node/215?fb_sig_in_iframe=1&fb_sig_iframe_key=0a8005f5594bd67041f88c6196192646&fb_sig_locale=en_US&fb_sig_in_new_facebook=1&fb_sig_time=1276093270.8711&fb_sig_added=1&fb_sig_profile_update_time=1274971926&fb_sig_expires=1276099200&fb_sig_user=100001144279508&fb_sig_session_key=2.LUla0LSemn0WISnLEEvxAA__.3600.1276099200-100001144279508&fb_sig_ss=gYb0NNI2QTFuLUSiUkAfow__&fb_sig_cookie_sig=e0ead4f64f9dd3327c1d60f48cd23102&fb_sig_ext_perms=auto_publish_recent_activity&fb_sig_country=us&fb_sig_api_key=093ae4c6af0fbc23e84d56838a82155d&fb_sig_app_id=112721765427901&fb_sig=89c4cd5c8e47a4487ea3e2e4fe5d0d4c
Referrer - http://apps.facebook.com/flixfling/node/215

However submitting a form (in this case the search form) the Location and Referrer look like this:
Location - http://flixfling.com/drupal_dev/search/node/drugs
Referrer - http://flixfling.com/drupal_dev/?fb_sig_in_iframe=1&fb_sig_iframe_key=0a8005f5594bd67041f88c6196192646&fb_sig_locale=en_US&fb_sig_in_new_facebook=1&fb_sig_time=1276092832.9162&fb_sig_added=1&fb_sig_profile_update_time=1274971926&fb_sig_expires=1276099200&fb_sig_user=100001144279508&fb_sig_session_key=2.LUla0LSemn0WISnLEEvxAA__.3600.1276099200-100001144279508&fb_sig_ss=gYb0NNI2QTFuLUSiUkAfow__&fb_sig_cookie_sig=e0ead4f64f9dd3327c1d60f48cd23102&fb_sig_ext_perms=auto_publish_recent_activity&fb_sig_country=us&fb_sig_api_key=093ae4c6af0fbc23e84d56838a82155d&fb_sig_app_id=112721765427901&fb_sig=93dfc5d7c96adb448912db7e0d427104

I'm guessing the Location not having the fb_sig... info is what is breaking the page out of the iFrame-designated theme and reverting to the default theme. The back traces don't seem to be showing any other theming function being called before init_theme - is the back trace listed in the same order as the function calls or reverse order? The back trace is showing inti_theme being called at the top of the list:

	init_theme backtrace

array(12) {
  [0]=>
  array(4) {
    ["file"]=>
    string(52) "/home/flix/public_html/drupal_dev/includes/theme.inc"
    ["line"]=>
    int(615)
    ["function"]=>
    string(10) "init_theme"
    ["args"]=>
    array(0) {
    }
  }

And to be complete the search submit shows the following themes chosen: 'init_theme has chosen flix, custom_theme is '. Other pages show: 'init_theme has chosen fb_flix, custom_theme is fb_flix'

Delving deeper and hoping this helps someone else....

Dave,
Looks like it's definitely a problem with the submit handlers. I gave the code ccshannon posted in #711654: form submit path/action not right? a shot, modifying it work over the search form:

function dff_custom_form_alter(&$form, $form_state, $form_id) {
  if(fb_canvas_is_iframe()) {
     if ($form_id == 'views_exposed_form') {
      // I don't want the exposed_view forms to redirect, but I may want to do something custom to the form(s) here
    } else {
      // By making the form's action target=_top, the form results leave the frame and load a new URL in the locator
      // But this will create the problem of 'relative URL' actions, and your resulting window will be of your Drupal site URL outside of FB chrome, in the site default theme
      // We will correct this later
  
      $form['#attributes'] = array('target' => '_top');
    }
  
  // Dave's suggestion below fixes the issue with exposed form results messing up the theme
  // So, THAT problem IS a theme problem
  
    if (fb_canvas_is_iframe()) {
      // Include the fb_sig so that when post is received, we know we are still in a canvas.                      
      foreach ($_REQUEST as $key => $value) {
        if (strpos($key, 'fb_sig') === 0) {
          $form['fb_canvas_iframe'][$key] = array(
            '#type' => 'hidden',
            '#value' => $value,
          );                                                                                                      
        }                                                                                                         
      }                                                                                                           
    }    
  
  // Now we setup how the results properly redirect
  // Also keep in mind that the links to your forms may contain a destination query string, and that other modules may redirect your forms for you
  // I suggest really getting to know your forms, their IDs and their submit handlers by checking the #submit array in $form
  
  // I picked this up from another Drupal discussion, and this works well for me.
  // With most other forms, you can just attach a submit handler to $form[#submit][] = 'my_handler_function', but to get the Node ID ...
    if (isset($form['search_block_form']) ) {
      if (fb_canvas_is_iframe()) {
        $form['#submit'][] = 'dff_custom_search_redirect_handler';
        if (isset( $_GET['destination'])) {
          $dest = $_GET['destination'];
          $fbpath = _dff_custom_my_fb_app_path();
          $pos = strpos($dest, $fbpath);
          if ($pos === FALSE) {
            $dest = $fbpath . '/' . $dest;
          }
          $form['custom_dest'] = array(
            '#type' => 'value',
            '#value' => $dest,
          );
        }
      }
    }

  }
}

function _dff_custom_my_fb_app_path() {
  $domain = 'http://apps.facebook.com/';
  $myapplabel = 'myapplabel';
  $path = $domain . $myapplabel;
  return $path;
}

function dff_custom_search_redirect_handler($form, &$form_state) {
    if (isset($form['custom_dest'])) {
      $form_state['redirect'] = $form['custom_dest']['#value'];
    } else {
      // This handler was added because we are in an iframe. So I just call for my fb path again
      $fbpath = _dff_custom_my_fb_app_path();
      $form_state['redirect'] = $fbpath . '/search/node/' . $form['#parameters'][1]['post']['search_block_form'];
    }
}

And lo and behold, it works! The search results are returned in the iFrame AND my FB iFrame theme is retained. Of course now I have a new problem: the search result links are not FB-ized, they send the user to the site. This happens on the drupalforfacebook.org site as well:
- Go to http://apps.facebook.com/drupalforfacebook/node/2000
- Search for somehting on the small search form (not the one up top).
- Results are returned in the canvas page.
- Click on any link and you go to the drupalforfacebook.org site instead of staying in the canvas page.

That's damned annoying, but a whole other issue if it could be considered that. I think it's outside of the scope of DFF and requires a custom function to work with the links the search.module returns. All I know is my boss wants the app to work in FB and never leave.

I tried taking commenting out the code above (target=top) and I started getting the FB chrome AND iFrame withing FB chrome jazz. Interesting.

I am wondering why you don't have the same problems too! I can provide a list of modules we have installed (there are quite a few) - I imagine DFF.org has more modest needs for additional modules. Even so, aside from Ubercart and the road to madness therein lies I can't think of too many other modules that are very form intensive that we need access to on the app.

Sounds about right on the search links. Anything I can do to help with that let me know.