HTTP code 200 and no data - error after upgrade

Enable fb devel module, reproduce problem, check logs (both watchdog and apache error logs). Let me know if you see anything.

Try going to your facebook app node and saving it again. Probably the URL is http://www.menashalibrary.org/node/11722/edit. Just hit submit even if you make no changes.

so fixed? Is iframe what you wanted?

If not, might simply be that the fb_fbml theme is not enabled?

Hmmm... possibly, the jquery_update.module error is happening before theme_init(). If so, the fb_fbml theme would never be initialized. I don't have that module or know what causes that error. But if you fix the error, canvas pages might work. What function is in that module, line 34?

So I really don't think this is related to the upgrade. I predict if you disable jquery_update module, the fb_fbml theme will work as expected.

Or change that code to have no errors/warnings.

If you disable it just temporarily or on a devel copy of the site, I'd be curious if it solves the problem. Until I hear a way to reproduce, I'm leaving this issue "fixed".

Can you check your logs? I'm curious what the apache access log says for the request returning no data.

Also is there anything in your apache or PHP error logs? I'm really not sure what's wrong.

Huh, you're log looks different from mine. I don't see all the browser ID information. You see that with the app set to FBML and not iframe? Weird that the request appears to come from both mozilla and safari at the same time.

The code 200 and no data is essentially the "white screen of death" but returned to facebook and not your browser. Those are usually caused by PHP fatal errors. Sometimes it's tricky to get PHP to report its errors. Do you have access to php.ini and can you make it more verbose? I don't know exactly what settings to tweak but google can probably tell you.

Hi Dave
I have recently installed the latest DFF modules ( core modules enabled , not contrib or optional)
followed all instructions in README.txt
and I have noticed that when I'm using FBML render option in application settings I can get only the frontpage. clicking on any specific post, or getting post by URL apps.facebook.com/myfbapp/node/2
will get the "returned HTTP code 200 and no data"
No errors written to APACHE log
and the most wierd - when I'm setting the devel info/2 block on the canvas footer area of the FB_FBML theme - the problem disappear , and I can get the specific post whether I click on it or by URL.

The problem dose not exists if the render option in application setting is set to Iframe. !!
for now I have no choice but to use the I frame but this is not a good solution as the FBML render method gives the look and feel of facebook
I know that these kinds of bugs are pain in the ... cause opening sort of "debug" mode information cause this problem to disappear

Thanks
Arin

The no data error is essentially the "white screen of death" but returned via facebook. I think nine times out of ten, PHP will give you the reason why, if you have proper error logging enabled, and know where to look for the error.

Check your apache access log to make sure facebook is actually pinging your server. And check php error log for further clues.

Hi Dave
thanks for dropping by. I have checked the access log and there is a ping:
69.63.186.246 - - [21/Feb/2010:20:02:43 +0200] "POST /fb_cb/5/node/4 HTTP/1.1" 200 -

however nothing from the php error log. ( I have set log_error = On and error_log = and error_reporting = E_ALL )
I do want to use the FMBL instead of of the iframe however I just can't, what am i doing wrong ?

Thanks for your help

Arin

I really don't know. Sounds very strange that things work when a certain block is enabled, and otherwise they fail. Without an error message I have no idea. Please let us know if you solve it or get more info.

Hi David
I have installed the new beta-3 version and noticed the following pattern:
when using the URL http://apps.facebook.com//
(only one "parameter" after the application name) things are ok - so I can reach the contact page, the user login page, any other custom page with no trailing arguments in the url etc
however if the URL include additional URL such as http://apps.facebook.com//user/password or http://apps.facebook.com//node/3 I get the above "200 code and no data" error.
I hope that give us a clue
I will happily pm you the url if you want
and I'm willing to do every step to further investigate that phantom bug

Thanks
Arin

Please submit a new issue when your question has nothing to do with the current thread.

That said, when you want to support canvas pages you need to create a canvas URL on the facebook application form (the one on facebook.com).

Hi Dave
Thanks for the prompt reply.
I will try to explain my self. the last post was not a new issue - it is the same old error that I still get (blank page). I just wanted to say that I recognize a pattern that might help in pinpointing it.
the pattern is quite simple - any URL that have more then one element after application name (equivalent to second drupal argument, like "node/2" for instance) will cause that problem, while URL with only one argument after the appname e.g. "node" or "page1" will display OK.
Please let me know if you want me to send you the actual URL so you can see for yourself

Thanks

Arin

Hi Dave,
I don't know if the original issue was ever resolved. In any case I have exactly the same issue (HTTP code 200 and no data).
It is a fresh installation, no upgrade. When canvas is set to iframe the page is displayed, when setting to FBML I get the error.
I changed my index.php file to log exactly what comes in and what gets out. The right parameters come in and it looks to me the correct output is produced and sent to the server. Log file attached.
Any suggestion welcome.

Some more information ...
I enabled the Facebook Devel Info block to be displayed in the canvas footer. By doing so the page is displayed correctly now.
The output produced is different now (see attached file). Try to hunting this down further ...

I find this problem and WSOD rarely occur without a log message being written somewhere. Configure your PHP to report more errors, look in php and apache error logs, etc.

Well Dave,
php and apache error log have no entry. Drupal's watchdog has no entry. Apache's access log shows three consecutive POSTs from facebook.
As you can see from the printout I attached, output IS produced. I assume that something in this output might be wrong so that fb interprets this as empty. I am using the standard fb_fbml theme. Nothing altered.

georgedamonkey,
would you mind changing for index.php file on a test installation to write input and output into a log file? I could then compare your log with mine and see if we both have the same problem or not. Here is the index.php file I use:

<?php
// $Id: index.php,v 1.94 2007/12/26 08:46:48 dries Exp $

/**
 * @file
 * The PHP page that serves all page requests on a Drupal installation.
 *
 * The routines here dispatch control to the appropriate handler, which then
 * prints the appropriate page.
 *
 * All Drupal code is released under the GNU General Public License.
 * See COPYRIGHT.txt and LICENSE.txt.
 */

require_once './includes/bootstrap.inc';
$fh = fopen('test.log', 'a');
$out = "GET:\n" . print_r($_GET, TRUE);
$out .= "POST:\n" . print_r($_POST, TRUE);
fwrite($fh, $out);
drupal_bootstrap(DRUPAL_BOOTSTRAP_FULL);

$return = menu_execute_active_handler();

// Menu status constants are integers; page content is a string.
if (is_int($return)) {
  switch ($return) {
    case MENU_NOT_FOUND:
      drupal_not_found();
      break;
    case MENU_ACCESS_DENIED:
      drupal_access_denied();
      break;
    case MENU_SITE_OFFLINE:
      drupal_site_offline();
      break;
  }
}
elseif (isset($return)) {
  // Print any value (including an empty string) except NULL or undefined:
  $out = theme('page', $return);
fwrite($fh, $out);
  print $out;
}

drupal_page_footer();
fclose($fh);

Make sure the root directory of your installation is writable by the web server. This creates a file test.log in the root directory in which you can see the GET and POST variables and the output produced by the theme.

Well, those two logs you've generated indicate that drupal is in fact returning something, in both cases. But facebook claims its not receiving. Maybe try wireshark or something like that to really see what's going on. Maybe add flush() to the very end of index.php.

Hi Guys
I have tried to revert to the normal setting of arg separator in the setting.php
and now I don't have the "200 code and no data" on the fbml
I currently have the beta-3 installed

ini_set('arg_separator.output', '&');

georgedamonkey, let me know what is the setup at your site and if it is only '&' try to revert it back to the default and see if the problem still exist

Best Regards

Arin

I may have found it... I'm not sure how this happened or how long it's been the case...

There's a mismatch in fb_canvas.module where ob_buffer is started and ended. See if this patch fixes...

Yeah! Worked!
Many thanks Dave.

Hi Dave
When are you planning to integrate the fix to the main branch ?

Arin
Algoma LTD
http://algoma.info

I didn't check in that fix exactly, but some code that accomplishes the same thing. this should not be an issue with the latest beta. Is it?

also I couldn't close this out until I found my amazon wish list! http://amzn.com/w/2USVELZVDSYQS

;)