Error on 'GetSaveFile()

in python API document, ‘GetSaveFile’ is explained like below.

GetSaveFile(message=None, ProposedFileName=None, filetypes=None)

so, I used like below.
fileName = GetSaveFile(‘save’, None, [‘xml’])

Usually I insert new name, it’s okay.
But, when I press an existing file(to overwrite something), fileName isn’t updated at all. It is ‘Untitled’ forever and I can’t get fileName which I pressed.
In usual File dialog, the file name is updated when I press an existing file.


What do you set as fileName?

edit: I improved it a bit that it accepts a full path, not only a file name.

this is what I used for my script.
fileName = GetSaveFile(‘export’, ‘groupSetting’, [‘xml’])
I want to save glyph groups to the file. Of course, as your mention, it is a full path.

I have used an alternative way with 'vanilla.dialog’
filePath = putFile(title=‘Export group setting’, fileName=‘groupSetting’, fileTypes=[‘xml’])