I'm making a document-based application, backed by core data, but I'm having serious issues opening the documents again. I'm trying to use readFromFileWrapper(wrapper, ofType:type, error:err) in an NSDocument subclass. Through my logging, it seems that this method is doing what it should, but the document that is displayed is not the object that I query inside that method, as can be seen by the two calls to "puts self" in the snippets below. def readFromFileWrapper(wrapper, ofType:type, error:err) url = NSURL.fileURLWithPath(self.fileName).URLByAppendingPathComponent("test.storedata") setFileType('SQLite') add_persistent_store(url) puts crags # This is a method that fetches objects from the sqlite database, # and proves to me that the database has been set right. Output below: # #<RFCrag_RFCrag_:0x4013323c0> # #<RFCrag_RFCrag_:0x4013324c0> # #<RFCrag_RFCrag_:0x401332680> # #<RFCrag_RFCrag_:0x401334480> # #<RFCrag_RFCrag_:0x401334740> # #<RFCrag_RFCrag_:0x4013355c0> # #<RFCrag_RFCrag_:0x40132f980> # #<RFCrag_RFCrag_:0x40132fc80> puts self # => #<RFDocument:0x40161bfe0> # Correct I think, this is what I expect true end This one is called from a "button_press(sender)" method once the opened document is on-screen, but the tableview is not populated. I would expect this to be an RFDocument also. def button_press(sender) puts self # => #<#<Class:0x40049db20>:0x4013e7680> # Incorrect? Or some funny cocoa-generated subclass maybe? end I don't know what this object is, but it doesn't have the persistent store set. Although I can then set it by calling a method from a menu that calls the "add_persistent_store(url)" method, and make the document window display the data. Am I missing something? I've been banging my head against this one for hours now. Any help is greatly appreciated. -- Stephen Horne