How do I catch switchApp failure?

Hi,

The only way for you to verify anything in Sikuli is visually inspect the screen.
So if you are expecting a certain application/webpage to appear on the screen, you should choose a visual component that will ensure that the relevant content is actually visible.

Cheers,
Eugene

Sikuli IDE is showing an error message saying it failed to find the window to switch to, therefore it is internally registering the issue. It is simply producing an error message that doesn't seem to have an associated exception I can use in the try-catch.

So, you mean that the problem is not with identifying the correct window but with switchApp itself?

If the application fails, the following will show up in the IDE messages but will not stop execution.

IDE messages:

[log] App.focus APPLICATION_NAME
[error] App.focus failed: APPLICATION _NAME not found

I need to have it stop execution and pass an error back to python (it is being called using subprocess.Popen to a premade script). What I don't see is a catchable exception, unlike if it fails to find a click target which gives a catchable 'FindFailed' exception. The reason this is important is that the software I have to work with is prone to crashing or popups, and in either case this will break sikuli, so I need to be able to handle this.

myApp = App.focus(...) # returns None in case of failing, App object otherwise

if not myApp:
    print "could not focus"

This works well for catching the error. However if I try to use sys.exit() to stop the script on this error (since if this error pops the script can't proceed), it throws a separate set of errors. Is there a special function I should be using to stop execution cleanly?

Error messages from using sys.exit():

[log] App.focus APPLICATION_NAME
[error] App.focus failed: APPLICATION_NAME not found
Focus_Fail
[error] script [ SCRIPT_NAME ] stopped with error in line 8
[error] Could not evaluate error source nor reason. Analyze StackTrace!
[error] Traceback (most recent call last):
File "C:\Users\USER\AppData\Local\Temp\sikuli-3814866394256187498.py", line 8, in <module>
sys.exit()
SystemExit

Thanks RaiMan, that solved my question.

After examining the documentation for sys more closely, I realize that this is standard behavior.

After more careful evaluation, this method for catching the error can only tell if the window has closed. It will return null if the window is not present. But if the window is present and simply fails to move to the front, this will not be caught. That seems to happen if running from inside another python script: the window icon on the taskbar will flash as if a message has appeared, but it will not actually bring the window forward, and thus the script fails to find things as they are behind other objects.

Is there a way to tell sikuli to look inside a specific window even if it is not on focus? Alternately, is there a way to get it to override the above issue and force the window forward?

--- sys.exit()

yes, this should not be used in Sikuli scripts.

Sikuli has it's own exit(n), to gracefully stop the script with an error code. exit() returns 0.

--- App.focus() and similar leads to flashing icon only
As far as I understand: this is a standard behaviour on Windows with the internally used Windows API features (... and can be seen with many other app situations running in background, but need the user's attention)

Thanks for posting a bug on this. I have accepted it for version 1.2 (... where the revision of the App class features is on the list anyway)