Question

I am trying to wrap up a plugin that I am writing but am stumped on a very trivial problem that I cant seem to find a solution for. I have tracked down almost every forum and related problem discussion. Any ways here is what I want to happen, my plugin has a timer that I would like the user to be able to handle its termination.

(function ($) {
...
var defaults = {
 callback : function(){},
 crossfadeTime : 1000,
 easing : 'linear',
 running : 'true', // Here is where I would like the user to send a parameter 
                   // to invoke a different result. i.e. 'false' => clearing 
                   // the timer. Such as...

var timer = setInterval(function(){
  // Do Something;
},3000);

if(defaults.running == 'false'){
  clearInterval(timer);
}

Answer 1

Do you really need them to be able to stop the timer by setting a variable? Could you do it by letting them call a function like this?

var TimerModule = (function(){
    var timerHandle;

    var startTimer = function(fnc, interval){
        if(timerHandle){
            //error, timer already running
            return;
        }
        timerHandle = window.setInterval(fnc, interval);
    };

    var stopTimer = function(){
        window.clearInterval(timerHandle);
        timerHandle = null;
    };

    return {
        start:startTimer,
        stop:stopTimer
    };

}());

TimerModule.start(function(){
    alert("Hieee");
}, 1000);

window.setTimeout(function(){
    TimerModule.stop();
}, 5000);

Otherwise, somethign like this would work:

var defaults = {
    callback: function() {
        alert("hi");
    },
    crossfadeTime: 1000,
    easing: 'linear',
    running: 'true' // Here is where I would like the user to send a parameter 
    // to invoke a different result. i.e. 'false' => clearing 
    // the timer. Such as...
};

var timer;
var timerFunction = function() {
    if (!defaults.running) {
        return;
    }
    defaults.callback();
    timer = setTimeout(timerFunction, 1000);
};

//start the timer
timerFunction();

window.setTimeout(function() {
    defaults.running = false;
},5000);

It uses setTimeout instead of interval, and doesn’t reset the timeout if running is false.

If you’re dead set on using setInterval, this will do the trick:

var defaults = {
    callback: function() {
        alert("hi");
    },
    crossfadeTime: 1000,
    easing: 'linear',
    running: 'true',
    callbackHandle: null
};

var timer;
var timerFunction = function() {
    if (!defaults.running) {
        window.clearInterval(defaults.callbackHandle);
        defaults.callbackHandle = null;
    }
    defaults.callback();
};

//start the timer
defaults.callbackHandle = window.setInterval(timerFunction,1000);

window.setTimeout(function() {
    defaults.running = false;
},5000);