[Jalene]

I'm currently working on a countdown timer for a quiz. However, the admin can set a quiz at different time intervals like 15, 30, 45, 60 mins. I used this as a php variable and is stored under a timer field in database and for the countdown I'm using a JavaScript. The problem I'm facing now is I don't know how to echo out the php variables in using the JavaScript. So once the the admin set 15 mins and a student click the quiz the 15 mins timer will start to count down and when it reaches 0 it will says "Time is up! End of quiz. Answers have been submitted successfully."

*Do take note that the time varies and not always 15 mins? Now I can only display out the time but it's not moving/counting down!

Please help! ):
Let me know if i need to use other javascript.

Here's my code to display out the timer:-

<?php
include 'dbFunctions.php';
$q_subchapter_no = $_POST['q_subchapter_no'];
$subChapter_id = $_POST['subchapter_no'];

$arrQuizzes = "SELECT timer FROM quiz
WHERE subchapter_no = '" . $subChapter_id . "' ";

$result = mysqli_query($link, $arrQuizzes);

if ($result) {
$row = mysqli_fetch_row($result);
$row = $row[0];
} else {
$msg = "Error";
}


*Timer: <?php echo $row; ?>


Here's the javascript that im using. Your help will be greatly appreciated.

var javascript_countdown = function ()
{
var time_left = 10; //number of seconds for countdown
var output_element_id = 'javascript_countdown_time';
var keep_counting = 1;
var no_time_left_message = 'The time is up! Your answers will be submitted.';

function countdown() {
if(time_left < 2) {
keep_counting = 0; //when it's 1 second, it will stop counting down.
}

time_left = time_left - 1;
}

function add_leading_zero(n) {
if(n.toString().length < 2) {
return '0' + n;
} else {
return n;
}
}

function format_output() {
var hours, minutes, seconds;
seconds = time_left % 60;
minutes = Math.floor(time_left / 60) % 60;
hours = Math.floor(time_left / 3600);

seconds = add_leading_zero( seconds );
minutes = add_leading_zero( minutes );
hours = add_leading_zero( hours );

return hours + ':' + minutes + ':' + seconds;
}

function show_time_left() {
document.getElementById(output_element_id).innerHT ML = format_output();//time_left;
}

function no_time_left() {
document.getElementById(output_element_id).innerHT ML = no_time_left_message;
}

return {
count: function () {
countdown();
show_time_left();
},
timer: function () {
javascript_countdown.count();

if(keep_counting) {
setTimeout("javascript_countdown.timer();", 1000);
} else {
no_time_left();
}
},
//Kristian Messer requested recalculation of time that is left
setTimeLeft: function (t) {
time_left = t;
if(keep_counting == 0) {
javascript_countdown.timer();
}
},
init: function (t, element_id) {
time_left = t;
output_element_id = element_id;
javascript_countdown.timer();
}
};
}();

//time to countdown in seconds, and element ID
javascript_countdown.init(1500, 'javascript_countdown_time');


Or any better javascript to recommend?

[alxkls]

well instead of going through all that why don't you make it 10 times easier-add an column in the database which would be a timestamp(the time when the quiz or whatever it is you are doing expires) and then use jquery and one of the many pluginst that do just that:

[Travis Weaver]

Hi there
If you just want to keep track of how long a guy was on a page simply use the following, at the top of your php page:

PHP Code:

$time = time();
$_SESSION['time_started'] = $time; 

Which stores the time (as a UNIX timestamp) that the page was loaded into the clients session.
To read it out and compare it with the time the next page is loaded, use the following:

PHP Code:

$oldtime = $_SESSION['time_started'];
$newtime = time();
$difference = $newtime - $oldtime; 

Well... and keeping track of the time remaining is a simple issue to solve:
Just keep a time remaining variable in your session, eg:

PHP Code:

      $time = time();
      $_SESSION['time_started'] = $time;
      $_SESSION['time_remaining'] = 2700; //45 minutes 

PHP Code:

      $oldtime = $_SESSION['time_started'];
      $newtime = time();
      $difference = $newtime - $oldtime;
      $_SESSION['time_remaining'] = $_SESSION['time_remaining'] - $difference;
      if ($_SESSION['time_remaining'] > 0)
      { 
          $_SESSION['time_started'] = $newtime; 
         //continue
      } else {
         //out of time
      } 

If you are happy with the answer, please give me a thanks.