Global Timer in Javascript with Multiple Callbacks

Question

I want to create a global timer object in javascript and then be able to add callbacks to it on the fly. This way I can just use one global timer in my script to execute all

Answer 1

Create a GlobalTimer object and give it the ability to register callback functions and cancel itself.

function makeGlobalTimer(freq) {
  freq = freq || 1000;

  // array of callback functions
  var callbacks = [];

  // register the global timer
  var id = setInterval(
    function() {
      var idx;
      for (idx in callbacks) {
        callbacks[idx]();
      }
    }, freq);

  // return a Global Timer object
  return {
    "id": function() { return id; },
    "registerCallback": function(cb) {
      callbacks.push(cb);
    },
    "cancel": function() {
      if (id !== null) {
        clearInterval(id);
        id = null;
      }
    }
  };
}

var gt = makeGlobalTimer(500);
gt.registerCallback(function() {
                      console.log("a");
                    });

gt.registerCallback(function() {
                      console.log("b");
                    });

setTimeout(function() { gt.cancel(); }, 5000);