Php timer does not stop at 00:00

Question

I have made a countdown timer using js ajax and php. The problem is this when the timer reaches 00:00 it doesnot perform the specified operation. instead timer starts from 59:59. Here is the code written:

    <span class="pull-right" id="time_left"></span>

    date_default_timezone_set('Asia/Karachi');
    echo $_SESSION['end_time'] = $quiz_end_time;

//timer function
        setInterval (function(){
            var xmlhttp = new XMLHttpRequest();
            xmlhttp.open("GET","timer.php",false);
            xmlhttp.send(null);
            document.getElementById("time_left").innerHTML = xmlhttp.responseText;
        }, 1000);

//timer.php code
<?php session_start();
    $from_time = date('Y-m-d H:i:s');
    $to_time = $_SESSION['end_time'];

    $time_form = strtotime($from_time);
    $time_to = strtotime($to_time);

    $difference = $time_to - $time_form;

    echo "Time Left: ";echo $timer_time = date("i:s",$difference);echo "<br>"; 
    //echo date ('H:i:s',strtotime($timer_time));

    if($timer_time == "00:00"){
        ?>
        <script>
            document.getElementById("quiz_form").submit();
            //window.location="manage-quizzes.php?Msg=quiz_ended"
        </script>
        <?php
        session_destroy($_SESSION['quiz_id']);
        session_destroy($_SESSION['end_time']);
        header('Location:manage-quizzes.php?Msg=quiz_ended');
    }else{
        echo "OKAY";
    }
?>

I am not sure what you are expecting to happen..... JavaScript does not execute with innerHTML. — epascarello, Mar 06 '18 at 13:42
https://stackoverflow.com/questions/2592092/executing-script-elements-inserted-with-innerhtml — epascarello, Mar 06 '18 at 13:47
Personally I would just return back an object that has either the time remaining or a boolean saying to submit and call subit from the Ajax code response. And using a synchronous call is a horrible idea since users will not be able to use the page as the call goes out. — epascarello, Mar 06 '18 at 13:48
How about comparing `$difference > 0` instead of hoping that you'll hit the precise moment when it's == 0? — Piskvor left the building, Mar 06 '18 at 13:49
@epascarello how to return time as i am not experienced with javascript — Faizan Zafar, Mar 06 '18 at 13:57

score 0 · Accepted Answer · answered Mar 06 '18 at 13:56

We cannot submit a form in AJAX file. Try this.

//timer function
setInterval (function(){
    var xmlhttp = new XMLHttpRequest();
    xmlhttp.open("GET","timer.php",false);
    xmlhttp.send(null);
    if (xhttp.response != "SUBMIT")
        document.getElementById("time_left").innerHTML = xmlhttp.responseText;
    } else {
        document.getElementById("quiz_form").submit();
    }
}, 1000);

//timer.php code
if ($timer_time == "00:00") {
    echo "SUBMIT";
} else {
    echo "OKAY";
}

Php timer does not stop at 00:00

1 Answers1