In what cases [NSDocument fileURL] can be nil?

Question

I'm creating the document with:

[NSDocumentController openDocumentWithContentsOfURL:display:completionHandler:] 

When I'm working with the instance of NSDocument and sometimes I'm getting crashes because document.fileURL == nil . What cases in NSDocument lifecycle can cause this?

Answer 1

在第一次保存文档之前， document.fileURL nil 。