Make AJAX Callbacks work within an iterator - php

Question

Why isn't this working? Only the success call for first response is working.
for(i = 1; i <= 6; i++) {
$.ajax({
url : 'runTest.php',
type : 'post',
data : "testNumber="+i+"&url=" + testUrl,
dataType : 'json',
success : function(data) {
var row = $('<tr />');
$('<td />').text(data.testName).appendTo(row);
$('<td />').text(data.testSeverity).appendTo(row);
$('<td />').text(data.testResult).appendTo(row);
$('<td />').text(data.testResultDetail).appendTo(row);
$('<td />').text(data.testDescription).appendTo(row);
$('table#results tbody').append(row);
}
});
}

Answer 1

There may be a problem on the server side. You're triggering the same PHP script six times at once; perhaps the database (or whatever) is locking on the first request and the other five return errors which you aren't checking for. In that case, you need to include some kind of while...sleep loop inside the PHP that waits until the database is available.
Here's what I did for a similar problem, when I was using a PHP script to retrive data from Google Maps and was running into request limits. But the idea is simple enough, and you should be able to modify it for your own needs:
$params = http_build_query($_GET);
$url = "http://maps.googleapis.com/maps/api/directions/json?sensor=false&" . $params;
$json = file_get_contents($url);
$status = json_decode($json)->status;
// check for over_query_limit status
while ($status=="OVER_QUERY_LIMIT") {
sleep(0.2); // seconds
$json = file_get_contents($url);
$status = json_decode($json)->status;
}