自定义500错误php页面，再次在30秒后重试POST或GET表单？

Question

We are trying to build a custom 500 error php page that retry the POST or GET form in 30 seconds again, we are using moodle for exams but sometimes we have a lot of students doing the same exam, any idea how to fix this problem? So far we can retry if the parameters are like xxx.php?name=doe but not if they come in an array form like $_post

<?php
    function my_url(){

        $url = (!empty($_SERVER['HTTPS'])) ?   "https://".$_SERVER['SERVER_NAME'].$_SERVER['REQUEST_URI'] : "http://".$_SERVER['SERVER_NAME'].$_SERVER['REQUEST_URI'];

        echo "<meta http-equiv=\"refresh\" content=\"30;url=$url\"/>";
    }
    my_url();

?>

Answer 1

You can use Javascript (if the client has it enabled) to attempt to reload the page. This will resubmit the POST data. The problem is (in Firefox at least) when the script executes, the browser pops up asking if they would like to resubmit data so that could be confusing.

This would work though:

<script type='text/javascript'>
    setTimeout('window.location.reload()', 30000);
</script>

Depending on what type of POST data you have, you could convert all the POST fields to hidden elements and re-populate another form on the page and give them the option to re-submit it after some period of time. You wouldn't be able to attempt to re-upload any files they submitted, but normal form data should work.

As Sam said in the comment, you could use similar code to resubmit the hidden form rather than calling window.location.reload(). This should prevent the "Are you sure you want to resubmit the data" popups most browsers will present.