Is this a bug in applab?


I think this project illustrates a bug in applab…

Expected behavior is that elements are hidden, then a prompt appears. Observed behavior is that the prompt appears and elements are still not hidden.

The code works correctly if you “sleep” for 1,000ms before requesting the prompt, or debug the code by stepping through line by line. Otherwise the code jumps straight to the dialogue prompt without hiding any elements


The code works as expected when you slow down the program (move slider closer to turtle). Since you want to start off your program with some elements hidden, change their setting to hidden in the screen design.


I have a student having a very similar issue. In her code ( if you run the code in “rabbit” mode the prompt pops up before the screen changes, but if you slow down the code a bit then it works fine. This does seem to be a problem with App Lab. I don’t see any issues with the code.


Shouldn’t the behavior be the same regardless of the speed that it is run?

The example I posted was a modification of a student’s original project. The original project wished to hide the elements in an event handler (not initially hiding the objects).

The workaround I suggested was using a “sleep” function to slow down the code, but I was wondering if this was in fact a bug in the way applab executes code.


Yeah, it does seem like a bug with AppLab!


@epsteingh I had a student with the same issue. I think this would be a great thing to submit through a “bug request” or through