handling nested callback functions

Question

handling nested callback functions

I need some help structuring my function w/ callbacks. The question: Is my logic performing how I imagine it?

app = getApp(function(val1, val2){
    helperFunction(val3, function(val4, val5, callbackTwo){
       //...logic
       var val6 = ....
       callbackTwo(val6)
    },
    function(val6){
        //logic
    });
};

function helperFunction(val3, callback, callbackTwo){
    //logic
    callback(val4, val5, callbackTwo);
}

Basically it works. However depending on my first anonymous callback function's logic, is there any chance that my callbackTwo function will be triggered before the assignment of val6?

javascript
node.js
asynccallback

Answer 1

That's pretty hilariously overwrought. Not sure why you're passing callback2 into/out of helperFunction, since it doesn't do anything with it. Instead, just invoke your 2nd callback's code directly in your original callback. Unless you can give us a reason (there is no obvious one), just put that logic inside your first callback.

I've cleaned it up as best I can, but you haven't given us real, syntactically-valid JavaScript to work with here:

App = getApp(function(val1, val2) {
  helperFunction(val3, function(val4, val5) {
    //...logic
    var val6 = ....
    //logic that uses val6, originally from callback2
  });
};

function helperFunction(val3, callback){
  //logic
  callback(val4, val5);
}

Note that "logic that uses val6" can just be another function invocation, but there is no reason to make that function an argument to helperFunction's callback.