functionName is not a function?

Question

I am trying to use a callback function to place data into an array. When i try to call my callback function 'myCallback' i get an error saying TypeError: callbackFunction is not a function. Here is an example of what the code looks like.

var content = [];

var function1 = function(){
  var function2 = function(){
    query = function(){
      //CAML code
    }
    success = function(callbackFunction){
      callbackFunction("text");// TypeError: callbackFunction is not a function
    }
    failure = function(){
      //Error code
    }
  }
  function2();
  runQuery(one, query, success, failure, two);//Main function
}

function1();

function callbackfunction(data){
  content.push(data)
}

I am following THIS Stack Overflow answer. Maybe I am getting something confused? Not really sure why it is throwing me the error when it is clearly defined in the code.

Thanks pals.

Well you defined them inside of function2() and function2 never runs... That pattern makes no sense... — epascarello, Sep 29 '16 at 19:19
It runs, my example is just that. An EXAMPLE. it might not look the same but it runs.. — IE5Master, Sep 29 '16 at 19:20
Well your example does not and that is what we have to go off of... — epascarello, Sep 29 '16 at 19:21
So now your issue is you defined callbackFunction as a variable, you need to pass the callback function into the function to start. — epascarello, Sep 29 '16 at 19:24

score 1 · Accepted Answer · answered Sep 29 '16 at 19:25

You redefined the variable, you need to pass it in.

var content = [];

var function1 = function(callbackfunction){
  var function2 = function(){
    query = function(){
      //CAML code
    }
    success = function(){
      callbackFunction("text");// TypeError: callbackFunction is not a function
    }
    failure = function(){
      //Error code
    }
  }
  function2();
  runQuery(one, query, success, failure, two);//Main function
}

function1(callbackfunction);

function callbackfunction(data){  
  content.push(data)
}

And if that is your actual code, you will have issues with global variables if you make more than one call.

score 0 · Answer 2 · answered Sep 29 '16 at 19:25

0

The variable named callbackFunction passes to the success function has any type but a function and can't be called.

answered Sep 29 '16 at 19:25

Dimava

7,654
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24

score 0 · Answer 3 · answered Sep 29 '16 at 19:25

You code is not very complete, but I could try to guess that problem is fllowing. You are trying to call a scoped method from inside the success callback, but you overshaddow its declaration by local variable.

success = function(callbackFunction){
  callbackFunction("text");// TypeError: callbackFunction is not a function
}

Try like this:

success = function(){
  callbackFunction("text");// TypeError: callbackFunction is not a function
}

And also move the declaration of the callback to be at the beginning of your code for better readability.

functionName is not a function?

3 Answers3