Question

What is the best practice for optional success and error callbacks in a function like this? Does this method make sense? It seems a little bloated to me.

Function Declaration:

var myFunc = function(myNumber, options){
    options = options || {};
    options.onSuccess = options.onSuccess || function(){};
    options.onError = options.onSuccess || function(){};

    var myNewNumber = myNumber * 2;

    if(newVar > 10){
        options.onSuccess(myNewNumber);
    }else{
        options.onError(myNewNumber);
    }
}

Calling it with callbacks:

myFunc(2,{
    onError: function(myNewNumber){
        // do stuff
    },
    onSuccess: function(myNewNumber){
        // do stuff
    }
})

Calling it without callbacks:

myFunc(2);

Answer 1

I would do it by checking the existence of the functions before calling them:

var myFunc = function(myNumber, options){
    options = options || {};

    var myNewNumber = myNumber * 2;

    if(newVar > 10){
        if (options.onSuccess) { options.onSuccess(myNewNumber); }
    }else{
        if (options.onError) { options.onError(myNewNumber); }
    }
}

It depends how many times you are likely to call these callbacks. If it is all over the place then your way might be better, or at least cleaner code.