Javascript redirect doesn't work immediately on PHP process finish

Question

Hi I'm just wondering why is it that my javascript redirect doesn't work immediately after my php respond? Here's the scenario, 1. I'm sending a post request to my php scripts. 2. My php scripts then process this and return a string "ok" to identify that the process is done (but my script is doing a background process which takes too long). 3. If the string is ok I will redirect the user to a confirmation page. But after returning the "ok" string my redirect don't take effect immediately it seems that its still waiting for the PHP process to finish. Below is my code

<?php 
    $success = $payment->do_payment();
    if (!$success) {
       throw new Exception("error on payment");
    }      

    set_time_limit(0);
    ignore_user_abort(true);
    header("Connection: close\r\n");
    header("Content-Encoding: utf-8\r\n");
    ob_start();

    echo "ok";  // This return to the frontend immediately

    $size = ob_get_length();
    header("Content-Length: {$size}", true);
    ob_end_flush();
    ob_flush();
    flush();
    // Below this line is a long php process that takes almost a minute
    $this->veryLongProcessRunningOnBackground();

and this is my jquery request

function payment_do_payment(token){
    $.ajax({
        url: '/payment',
        data:{
            mydata: "The data"
        },
        success: function(txt){
            if (txt == "ok"){
                console.log("done redirecting now");
                window.location.href = "/confirmation-page";
            }else{
                alert("Failed to process");
            }
        },
        type: 'POST'
    });
}

Answer 1

You will need to use something like a socket connection to do this.

Maybe this post will help.