Finish all asynchronous requests before loading data?

Question

I have run into an issue where I have multiple asynchronous requests occuring which grab images and information from the Facebook API and my Firebase database. I want to per

Answer 1

One Idea i have used is to place an if statement check inside the query statement call back and place the query statement call back in a for loop (so you can loop through all of your queries), so the if statement should check if this the last call back expected, then you should execute a return statement or a deferred.resolve statement, the following is a concept code.

var list=fooKeys //list of keys (requests) i want to fetch form firebase
var array=[]  // This is the array that will hold the result of all requests 
for(i=xyz;loop breaking condition; i++){
    Ref = new Firebase("https://yourlink.firebaseio.com/foo/" + fooKeys[i]);
   Ref.once("value", function (data) {
       array.push(data.val());
       if(loop breaking condition == true){
           //This mean that we looped over all items
           return array;  //or deferred.resolve(array);
       }
   })
}

Putting this code in a function and call it asynchronously will give you the ability to wait for the whole results before proceed in doing other stuff.

Hope you (and the others) find this beneficial.