Javascript: Can't stop the setTimeout

Question

I'm working on a proxy server checker and have the following code to start the requests at intervals of roughly 5 seconds using the setTimeout function;

        function check() {

            var url = document.getElementById('url').value;
            var proxys = document.getElementById('proxys').value.replace(/\n/g,',');

            var proxys = proxys.split(",");

            for (proxy in proxys) {

                var proxytimeout = proxy*5000;

                t = setTimeout(doRequest, proxytimeout, url, proxys[proxy]);

            }
        }

However I can't stop them once their started!

        function stopcheck() {

            clearTimeout(t);

        }

A fix or better method will be more that appreciated.

Thank you Stack Overflow Community!

Answer 1

There are 2 major problems with your code:

1. t is overwritten for each timeout, losing the reference to the previous timeout each iteration.
2. t is may not be a global variable, thus stopcheck() might not be able to "see" t.

Updated functions:

function check() {
    var url         = document.getElementById('url').value;
    var proxys      = document.getElementById('proxys').value.replace(/\n/g,',');
    var timeouts    = [];
    var index;
    var proxytimeout;

    proxys = proxys.split(",");
    for (index = 0; index < proxys.length; ++index) {
        proxytimeout                = index * 5000;
        timeouts[timeouts.length]   = setTimeout(
            doRequest, proxytimeout, url, proxys[index];
        );
    }

    return timeouts;
}

function stopcheck(timeouts) {
    for (var i = 0; i < timeouts.length; i++) {        
        clearTimeout(timeouts[i]);
    }
}

Example of use:

var timeouts = check();

// do some other stuff...

stopcheck(timeouts);

Answer 2

Where is 't' being defined? It keeps being redefined in the for loop, so you will loose track of each timeout handle...

You could keep an array of handles:

var aTimeoutHandles = new Array();
var iCount = 0;
for (proxy in proxys) {

    var proxytimeout = proxy*5000;

    aTimeoutHandles[iCount++] = setTimeout(doRequest, proxytimeout, url, proxys[proxy]);

}