I wrote a simple module to demonstrate the use of a progress bar for downloading files or other server side events. Everything works as expected except for the timing of the "onComplete" callback attached to the tween. It appears to execute the callback at the beginning of the animation instead of the end. I'm sure the issue is with my code but I do not understand why it is happening. To view the issue, press any of the buttons on the codepen page. I attached an alert at the very end of the progress bar (100%) that freezes the animation. Note the values of the header text, footer text and bar text.