I have a dynamic var someString: String? = nil attribute in my class bound to an UI text field. The text field is configured to display a placeholder string when someString is empty (nil). But when I run the application the placeholder string does not show up even though someString is explicitly set to nil. I can remember the same window backed up with Objective-C code instead of Swift worked as expected and the text field shown the placeholder when the string was empty, but I cannot check it now to be sure. Anyway, is this a bug in Swift, or am I doing something wrong?
I've just found that there is "Null Placeholder" option in the Value binding configuration. That seems to override "Placeholder" setting in the Attributes inspector. So the question is closed.