Using a variable named 'grp' on a SHAC = bad

I could find no posts regarding folks stepping on this particular rake and getting smacked in the face by its handle.

In hindsight it was a silly mistake.

I inadvertantly declared a numeric variable called 'grp' in a script, and things went absolutely fine for weeks until... I tried to use Get/SetUserParam in that script.

Then suddenly:

Code:

Library cbuslogic:0: attempt to index global 'grp' (a number value)
stack traceback:
 Library cbuslogic: in function 'SetUserParam'

It took me an awkwardly long while to work out what was happening, as an identical SetUserParam command was executing successfully in this script's init code.

The reserved global 'grp' was being clobbered by my script elsewhere in a function. My 'grp', which was a number, should have been declared as 'local' or had its name changed altogeter. The functions Get/SetUserParam, and I'm sure loads more depend on the global 'grp' being left unmolested, and fair enough.

D'oh. I won't make that mistake again.

 

Definitely come across this one a few times, so you arent alone.

You are right though, grp is a global variable which has some functionality behind it.

For example I use grp.getvalue(event.dst) to get the value of any group address regardless of the application. Its a sneaky little work around for not having to bother detecting the application and use the appropriate C-Bus function