Stop long running programs in client-side JS

[fpereiro]

• Closes while loop lvl 17 making Hedy unresponsive #560
• Stops Python program execution in the client after 3 seconds
• Prints a modal

How to test:

• Go to http://localhost:5000/hedy/17
• Run this code:

a is True
while a is True:
    b is 1

• See that a modal appears after three seconds and that code execution is indeed interrupted.

@Felienne suggestions to the shown text are welcome! Once we agree on the text, I can add the text entry to the yamls.

[Felienne]

Hi @fpereiro

Seems to work well, but we get a modal and also the regular error box:

Not sure if that's what I specified but just the regular error box is fine. As for the text, this is fine, if you just put this in the yaml I can make updates myself.

[Felienne]

Ow and one more thing, if a program also prints, like this:

a is True
while a is True:
    print('lalala')

we first get nothing for 3 secs, then the popup and then all the output. I guess it might not be possible because it might requires threads or the like but could we get all output first and then after 3 secs the popup?

[Felienne]

Can we put this value in a function that depends on level? For now the function can just be any level returns 3000 but that gives us the flexibility to change it depending on level.

[Felienne]

I think you replied to this somewhere (Slack?) but I forgot the answer :) Can you repeat it here?

[fpereiro]

Hi @Felienne !

• I just removed the modal and left the standard red error box.
• The text is added as an error coming from the YAML instead of hardcoded in app.js.
• The timeout is provided by an IIFE (immediately executed function) and can be customized according to level later.
• It might be possible to print output as we go, but after digging some time through Skulpt, I'm not sure if it is possible. Skulpt itself is sparsely documented, and after digging in the implementation file for the overall family of methods we use to execute Python misceval, see here: https://github.com/skulpt/skulpt/blob/master/src/misceval.js , I don't see an obvious way to do it. If this is indeed a feature worth pursuing, I suggest we work on it as a separate issue.

[Felienne]

Hi @Felienne !

• I just removed the modal and left the standard red error box.
• The text is added as an error coming from the YAML instead of hardcoded in app.js.
• The timeout is provided by an IIFE (immediately executed function) and can be customized according to level later.
• It might be possible to print output as we go, but after digging some time through Skulpt, I'm not sure if it is possible. Skulpt itself is sparsely documented, and after digging in the implementation file for the overall family of methods we use to execute Python misceval, see here: https://github.com/skulpt/skulpt/blob/master/src/misceval.js , I don't see an obvious way to do it. If this is indeed a feature worth pursuing, I suggest we work on it as a separate issue.

ok, thanks for the updates! Will try this tomorrow.

[Felienne]

Hi @fpereiro

Thanks for the updates! The execution order can be a problem though, it leads to really confusing behavior.
f.e. the current implementation prohibits programs with input, f.e. this at level 7:

repeat 3 times
    dier is ask 'Welk dier kies je?'
    print 'En wie rijdt er op zijn ' dier ' door de prairie?'

After the first input, it no longer works. So maybe we need to turn the timer off for programs with ask?

Also... if you use read loud it gets interesting on your demo program, it reads once, then gives the error and then continues.

But I can imagine this all gets too complex and you want to stop working on this request? That is understandable too!!

[fpereiro]

@Felienne I found a way to update the timer if there's an ask. Use the following code to test:

foo is input('bar?')
a is True
while a is True:
    b is 1

[Felienne]

@Felienne I found a way to update the timer if there's an ask. Use the following code to test:

foo is input('bar?')
a is True
while a is True:
    b is 1

Nice, this is almost perfect! There is a small thing, no sure whether we can do something about it but when I enter text, the input box does not disappear until the timeout error message appears. First I thought it had not processed my input. Can that be improved (if not, we can leave it is as)

[fpereiro]

HI @Felienne ! Ready to test again :). I added a timeout to ensure that the modal box is hidden before running the program.

How to test:
Go to http://localhost:5000/hedy/18
Enter this program:

foo is input('bar?')
a is True
while a is True:
    b is 1

After answering the question, the modal box should go. For three seconds, nothing should happen. Then, after three seconds, an error should be shown.