Q:

How to disable the auto-reopening of the last document?

How to disable the auto-reopening of the last document ?

When I execute my application, it calls the method readFromData.
But, the problem is that between my version 1 and my version 2, I changed the structure of the data that is saved by the application. In v1, the root object was an array. In v2, the root object is a dictionnary with two keys, one for a string, and one for an array.
When the application loads, it seems that it load from the data an array and then tries to get from this array an object for the keys of the dictionnary.
What shall I do !!??
PS : I tried to create a NSApplicationDelegate with
        -(BOOL)applicationShouldOpenUntitledFile:(NSApplication*)app
        {
            return YES; 
        }

        - (BOOL)applicationOpenUntitledFile:(NSApplication *)sender
        {
            return YES ;
        }

but these methods are never called by my application.

EDIT : 
Here is the call stack : 
0   CoreFoundation                      0x00007fff8bc06f56 __exceptionPreprocess + 198
1   libobjc.A.dylib                     0x00007fff81f37d5e objc_exception_throw + 43
2   CoreFoundation                      0x00007fff8bc931be -[NSObject doesNotRecognizeSelector:] + 190
3   CoreFoundation                      0x00007fff8bbf3e23 ___forwarding___ + 371
4   CoreFoundation                      0x00007fff8bbf3c38 _CF_forwarding_prep_0 + 232
5   dictionnaireDouchoutique            0x0000000100007f22 -[Document readFromData:ofType:error:] + 498
6   AppKit                              0x00007fff89af3558 -[NSDocument readFromURL:ofType:error:] + 665
7   AppKit                              0x00007fff8999198c -[NSDocument _initForURL:withContentsOfURL:ofType:error:] + 151
8   AppKit                              0x00007fff89991890 -[NSDocument initForURL:withContentsOfURL:ofType:error:] + 360
9   AppKit                              0x00007fff89991677 -[NSDocumentController makeDocumentForURL:withContentsOfURL:ofType:error:] + 199
10  AppKit                              0x00007fff8999150f __-[NSDocumentController reopenDocumentForURL:withContentsOfURL:display:completionHandler:]_block_invoke_5 + 150
11  AppKit                              0x00007fff89991467 __-[NSDocumentController reopenDocumentForURL:withContentsOfURL:display:completionHandler:]_block_invoke_4 + 697
12  AppKit                              0x00007fff899911a9 -[NSDocumentController _openDocumentWithContentsOfURL:usingProcedure:] + 530
13  AppKit                              0x00007fff89990d95 __-[NSDocumentController reopenDocumentForURL:withContentsOfURL:display:completionHandler:]_block_invoke_3 + 242
14  libdispatch.dylib                   0x00007fff86329a82 _dispatch_call_block_and_release + 18
15  libdispatch.dylib                   0x00007fff8632b8f2 _dispatch_main_queue_callback_4CF + 308
16  CoreFoundation                      0x00007fff8bb9be7c __CFRunLoopRun + 1724
17  CoreFoundation                      0x00007fff8bb9b486 CFRunLoopRunSpecific + 230
18  HIToolbox                           0x00007fff87d652bf RunCurrentEventLoopInMode + 277
19  HIToolbox                           0x00007fff87d6c56d ReceiveNextEventCommon + 355
20  HIToolbox                           0x00007fff87d6c3fa BlockUntilNextEventMatchingListInMode + 62
21  AppKit                              0x00007fff8973d779 _DPSNextEvent + 659
22  AppKit                              0x00007fff8973d07d -[NSApplication nextEventMatchingMask:untilDate:inMode:dequeue:] + 135
23  AppKit                              0x00007fff897399b9 -[NSApplication run] + 470
24  AppKit                              0x00007fff899b5eac NSApplicationMain + 867
25  dictionnaireDouchoutique            0x00000001000075d2 main + 34
26  dictionnaireDouchoutique            0x0000000100001984 start + 52

A:

Use NSPropertyListSerialization to deserialize the data, then use respondsToSelector: or isKindOfClass: checks to see what kind of root object it handed you. If it's an array, handle that; if it's a dictionary, handle that; if it's anything you don't recognize, return an error indicating that the file is garbage.

