javascript - setTimeout / clearTimeout problems

Question

I try to make a page to go to the startpage after eg. 10sec of inactivity (user not clicking anywhere). I use jQuery for the rest but the set/clear in my test function are pure javascript.

In my frustation I ended up with something like this function that I hoped I could call on any click on the page. The timer starts fine, but is not reset on a click. If the function is called 5 times within the first 10 seconds, then 5 alerts will apear... no clearTimeout...

function endAndStartTimer() {
    window.clearTimeout(timer);
    var timer;
    //var millisecBeforeRedirect = 10000; 
    timer = window.setTimeout(function(){alert('Hello!');},10000); 
}

Any one got some lines of code that will do the trick? - on any click stop, reset and start the timer. - When timer hits eg. 10sec do something.

Answer 1

You need to declare timer outside the function. Otherwise, you get a brand new variable on each function invocation.

var timer;
function endAndStartTimer() {
  window.clearTimeout(timer);
  //var millisecBeforeRedirect = 10000; 
  timer = window.setTimeout(function(){alert('Hello!');},10000); 
}