How to show NSAlert using Sheet window in separate .XIB files? - applescript-objc

Question

I have a button to perform a task and if an error occurs during the process a warning is displayed using NSAlert "Sheet window"
in this moment I am using multiple .XIB files in a project, I can't display the "Sheet window" in these files(.XIB) is there any way to do this?
Thanks in advance!
on clickedButton:sender
try
--some code here...
on error errorMsg
set alert to current application's NSAlert's alloc's init()
tell alert
its setMessageText:"This is an ERROR"
its setInformativeText: "Error: " & errorMsg
its setAlertStyle:2
its beginSheetModalForWindow:theWindow modalDelegate:me didEndSelector:(missing value) contextInfo:(missing value)
end tell
end try
end clickedButton:

Answer 1

If you don't have a window to put the sheet on, you will need to run the normal alert dialog. You can test for a window by using NSApp's mainWindow(), which will be missing value if there isn't one, and do either alert's runModal() or the sheet depending on the result:
use framework "Cocoa"
use scripting additions
property theWindow : missing value -- this will be the main window...
property sheetOrNot : true -- ... or not, depending on this flag
on run -- this lets the example run from the Script Editor if you forget the main thread thing
my performSelectorOnMainThread:"doWindow" withObject:(missing value) waitUntilDone:true
my performSelectorOnMainThread:"doAlert" withObject:(missing value) waitUntilDone:true
end run
on doWindow() -- create a window to play with
set theWindow to current application's NSWindow's alloc's initWithContentRect:{{200, 400}, {400, 200}} styleMask:7 backing:(current application's NSBackingStoreBuffered) defer:true
set theWindow's releasedWhenClosed to true
if sheetOrNot then tell theWindow to makeKeyAndOrderFront:me
end doWindow
on doAlert() -- show the alert
try
--some code here...
error "oops" -- ...that went badly
on error errorMsg
set alert to current application's NSAlert's alloc's init()
tell alert
its setMessageText:"This is an ERROR"
its setInformativeText:("Error: " & errorMsg)
its setAlertStyle:2
if current application's NSApp's mainWindow() is not missing value then
its beginSheetModalForWindow:theWindow modalDelegate:me didEndSelector:(missing value) contextInfo:(missing value)
else -- no window, so do a normal modal dialog
its runModal()
end if
end tell
end try
end doAlert