"try...on error" not working

Scripting Forums AppleScript Studio & Xcode
#1

While working on my project to get the name and class of every named object in an ASS app. I have come upon a problem that I don’t know how to solve:

...
	set theViews to every view of every window of me
	set thePairs to CreateNIBPairs(theViews)
....

to CreateNIBPairs(CNPViews)
	set CNPPairs to {}
	repeat with x from 1 to count of CNPViews
		set cnpView to item x of CNPViews
		repeat with y from 1 to count of cnpView
			try
				set cnpName to name of item y of cnpView  --> 1
			on error errNum
				set cnpName to ""
			end try
			if cnpName is not "" then  -->  2
			...
			...

The problem occurs when an item without a name is encountered. The “name” property will contain missing value. When the line of code indicated by arrow #1 is executed, no error is generated and cnpName is no longer defined, creating an error on the line indicated by arrow #2. My thought is that if no name was present, an error WOULD be generated and cnpName should be set to “”. The “on error” portion (errNum included in a debugging effort) of the script is never encountered.

Any help will be grately appreciated,
Brad Bumgarner, CTA

OS X 10.4.2
Xcode 2.1

#2

Could you test for missing value (it is a valid reference), and then set ‘cnpName’ to an empty string if it’s encountered?

to CreateNIBPairs(CNPViews)
	set CNPPairs to {}
	repeat with x from 1 to count of CNPViews
		set cnpView to item x of CNPViews
			repeat with y from 1 to count of cnpView
				try
					if (name of item y of cnpView) is missing value then --> Check for 'missing value'
						set cnpName to ""
					else
						set cnpName to name of item y of cnpView
					end if
				on error errNum
					set cnpName to ""
				end try
			if cnpName is not "" then
				...

j

#3

Thank you!

I was setting the name and checking THAT. NOT directly checking the property of the object.

Thanks again … now I can continue.:smiley:
Brad Bumgarner, CTA