>>>I want to know whether a class exists in a certain library before I try to instantiate it in my program (reason: I don't want to get an error message if it doesn't exist). I couldn't find a function for this and the only thing I could come up with is to open the class library programatically and search for objname. This worked, but I felt a little uneasy about touching the .vcx from within a program.
>>>
>>>Can anyone offer any advice, caveats, etc. on this?
>>>
>>>Thanks,
>>>
>>>Sylvia
>>
>>You can put error trap on CREATEOBJECT() line and check for errors without interrupting of program flow.
>
>I already have an error routine in place for the whole program, which under normal circumstances writes errors to a file, then closes down. I thought about temporarily swapping out that routine with another to check for just this error condition, but it started getting into a lot of steps, so I started looking for an alternative.
Local error trap is very simple:
Local cError,lErrorflag
cError=on("ERROR")
on error lErrorfalg=.t.
oMyobject=createobject("myclass")
on error &cError.
if lErrorfalg=.t.
return 1
else
return 2
endif
Edward Pikman
Independent Consultant