Question

Ok, having an issue withe the return value of a function always returning “undefined”

Heres my code:

//called here:
var res = comms(GENSET_SN);

//the function
function comms(genserial) {
     var Result; 
     //Webservice called here
     MyServices.getCommsState(genserial, "S1", OnComplete1);

     function OnComplete1(args) {
          var Res = eval("(" + args + ")");

          if (Res == 1) {
               Result = 1;
          } else {
                Result = 0;
          }
      }
      return Result;
}

please help!!

Answer 1

I’m guessing MyServices.getCommsState(genserial, "S1", OnComplete1); is an ajax request?

If so, the value of Result will be returned before it is actually set in the OnComplete1 callback, hence undefined.

You will need to pass in a callback function containing the code that will use the Result value.

You can change the code to do this instead, note that you pass in the function to comms and then call it in OnComplete1:

comms(GENSET_SN, function(res) {
    // do whatever you need with res here!
});

//the function
function comms(genserial, callback) {
     //Webservice called here
     MyServices.getCommsState(genserial, "S1", function(args) {
         var Res = eval("(" + args + ")"); // I would change this aswell, dont use eval!
         callback(Res == 1 ? 1 : 0);
     });            
}