Keep getting error when using a js Ticker with a dynamic text field

Forum|Forum|20 days ago
September 16, 2026
6 replies
44 views

I’m working on incrementing a dynamic text field over time. I’ve tried a few different methods but the Ticker seems to be the best, but for some reason I keep getting a “Cannot set properties of undefined (setting 'text')” error when trying to set the field in the Ticker function.

I’ve tried setting the text field outside the function and it works just fine. I’ve also tried initializing the text field in a frame well in advance of the function, but that didn’t help either. If I send the function output to the console instead of the text field, it works just fine.

Here’s my code. Any ideas?

Thanks!

var i = 0;

createjs.Ticker.on("tick", tick);
function tick() { 

    this.bunting_count.text = i;

    //console.log(i); 
    i++;
    }

J

Jovial_dynamism411cAuthor

Participant

Hey thanks! That did the trick! I’m guessing I needed to define the scope for the ticker before it would work with the dynamic text field I defined?

JoãoCésar17023019

Community Expert

If you don’t set the scope, the default value for the “this” keyword inside of a event handler function will be the global window. So you either need to pass the scope, or maybe store a reference to the object on stage you want to access in variable outside the function, or also use bind.

I

Impressive_Light3285

Participating Frequently

One thing I’d check is the Ticker callback timing. The callback may be firing before the text field has been created or added to the display list. Try starting the Ticker only after the text field is initialized, and verify the instance name matches exactly.

A

adventurous_Fluttere400

Known Participant

It sounds like the text field reference is undefined when the Ticker callback runs. I’d check that the field exists before assigning .text, and make sure the callback is using the correct scope/reference to the dynamic text field. Logging the field itself inside the Ticker would also confirm whether it’s available at that point.