Question

I’m attempting to do an AJAX call (via JQuery) that will initiate a fairly long process. I’d like the script to simply send a response indicating that the process has started, but JQuery won’t return the response until the PHP script is done running.

I’ve tried this with a ‘close’ header (below), and also with output buffering; neither seems to work. Any guesses? or is this something I need to do in JQuery?

<?php  echo( 'We'll email you as soon as this is done.' );  header( 'Connection: Close' );  // do some stuff that will take a while  mail( '[e-mail]', 'okay I'm done', 'Yup, all done.' );  ?> 

Answer 1

The following PHP manual page (incl. user-notes) suggests multiple instructions on how to close the TCP connection to the browser without ending the PHP script:

• Connection handling ^Docs

Supposedly it requires a bit more than sending a close header.

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OP then confirms: yup, this did the trick: pointing to user-note #71172 (Nov 2006) copied here:

Closing the users browser connection whilst keeping your php script running has been an issue since [PHP] 4.1, when the behaviour of register_shutdown_function() was modified so that it would not automatically close the users connection.

sts at mail dot xubion dot hu Posted the original solution:

<?php header('Connection: close'); ob_start(); phpinfo(); $size = ob_get_length(); header('Content-Length: $size'); ob_end_flush(); flush(); sleep(13); error_log('do something in the background'); ?> 

Which works fine until you substitute phpinfo() for echo('text I want user to see'); in which case the headers are never sent!

The solution is to explicitly turn off output buffering and clear the buffer prior to sending your header information. Example:

<?php ob_end_clean(); header('Connection: close'); ignore_user_abort(true); // just to be safe ob_start(); echo('Text the user will see'); $size = ob_get_length(); header('Content-Length: $size'); ob_end_flush(); // Strange behaviour, will not work flush(); // Unless both are called ! // Do processing here  sleep(30); echo('Text user will never see'); ?> 

Just spent 3 hours trying to figure this one out, hope it helps someone 🙂

Tested in:

• IE 7.5730.11
• Mozilla Firefox 1.81

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Later on in July 2010 in a related answer Arctic Fire then linked two further user-notes that were-follow-ups to the one above:

• Connection Handling user-note #89177 (Feb 2009)
• Connection Handling user-note #93441 (Sep 2009)