Use Ajax to show progress of a PHP script called by another Ajax request

Question

I make a jQuery Ajax call to a PHP script that runs for a decent amount of time (between 1- seconds and 3 minutes). It constantly logs a percentage of completion in a database. How can I continually run another Ajax request at the same to report the percentage complete from the MySQL database to the user?

EDIT I understand how to use a separate PHP script to query the database, so my question is more how to set up the JavaScript and Ajax calls

Answer 1

After your AJAX call to kick off your process, you could make another AJAX call in a loop which requests, returns, and presents the current percentage complete until it reaches 100%. Basically, one AJAX call to initiate the process and then a series of calls which check status.

Update: Here is some simple JavaScript to achieve what you want:

<script>
function startProcess() {
    //start your long-running process
    $.ajax(
            {
                type: 'GET',
                url: "/longRunningProcess",
                async: true,
                success:
                    function (data) {
                        //do something - your long process is finished
                    }
            });
}
function getStatus() {
    //check your progress
    $.ajax(
            {
                type: 'GET',
                url: "/checkProgress",
                async: true,
                success:
                    function (data) {
                        //assume the data returned in the percentage complete
                        var percentage = parseInt(data);

                        //write your status somewhere, like a jQuery progress bar?

                        if (percentage < 100) {
                            //if not complete, check again
                            getStatus();
                        }
                    }
            });
}