WhenReady object. Fires callback when all conditions are satisfied.

whenready.js

//executes a callback when all conditions are satisfied
function WhenReady(obj, cb) {
	this.conditions = obj;
	this.readyCallback = cb;
}

WhenReady.prototype = {
	
	satisfyCondition: function(o) {
		if(typeof o == 'object') {
			for(var key in this.conditions) {
				if(o[key]) {
					this.conditions[key] = o[key];
				}
			}
			//see if all conditions are satisfied, fire readyCallback if they are
			this.go();
		}
	},

	go: function() {
		var alldone = true;
		//check if all conditions satisfied
		//if one is false, then don't execute
		for(var key in this.conditions) {
			if(this.conditions[key] === null) {
				alldone = false;
				break;
			}
		}
		if(alldone) {
			//execute the final callback
			this.readyCallback();
		}
	}

};



//example usage

//init object with conditions and callback
var when = new WhenReady({
  ajaxCall: null,
  timer: null
}, function(){ 
  console.log('DONE'); 
});

$.ajax({ 
  url: "http://echo.jsontest.com/",
  success: function(data){
    when.satisfyCondition({ ajaxCall: true });
  } 
});

setTimeout(function() {
  when.satisfyCondition({ timer: true });
}, 100);