Core Data: Simply set NSMigratePersistentStoresAutomaticallyOption in a Document?
Well, it's time to move my beta testers from 0.1.8 to 0.1.9 and this requires a Core Data database migration. Since the app requires 10.5, I can use Default Automatic Migration. Yippee. Up to this point, my NSPersistentDocument subclass had used the Persistence Stack which is built into NSPersistentDocument. However, this stack apparently does not create set NSMigratePersistentStoresAutomaticallyOption in its store. It looks to me like I need to override -managedObjectContext and implement that whole persistence stack enchilada just to set this one little, commonly-used option. Is there a shortcut? If indeed I need to implement the stack, where is the best place to splice in the pieces? I had been creating new documents from a wizard using -[NSDocumentController openUntitledDocumentAndDisplay:error:], and doing some configuration which required the moc at the end of -init. Now that doesn't work since I can't set a store in new documents before the fileURL has been set, which happens later. I'm imagining many ways to move things around, but I'd like to start out by doing it the *right* way. Sincerely, Jerry Krinock P.S. Sorry if this is in the list archives but since cocoabuilder.com is down I'm searching lists.apple.com. Searching with Search for: NSMigratePersistentStoresAutomaticallyOption Match: All Find: Substring Located In: Whole Document Listname Matches: cocoa-dev I get: Sorry, your search for NSMigratePersistentStoresAutomaticallyOption did not find any results. No documents were found containing NSMigratePersistentStoresAutomaticallyOption. Seems unbelievable.___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: Core Data: Simply set NSMigratePersistentStoresAutomaticallyOption in a Document?
P.S. Sorry if this is in the list archives but since cocoabuilder.com is down I'm searching lists.apple.com. Searching with Search for: NSMigratePersistentStoresAutomaticallyOption Match: All Find: Substring Located In: Whole Document Listname Matches: cocoa-dev I get: Sorry, your search for NSMigratePersistentStoresAutomaticallyOption did not find any results. No documents were found containing NSMigratePersistentStoresAutomaticallyOption. Seems unbelievable. I can't help with your question but Googling NSMigratePersistentStoresAutomaticallyOption site:lists.apple.com yields 36 results. There's probably several duplicates but it give you a head start Matt ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: Core Data: Simply set NSMigratePersistentStoresAutomaticallyOption in a Document?
On 2009 Nov 19, at 14:05, Matthew Lindfield Seager wrote:
I can't help with your question but Googling
NSMigratePersistentStoresAutomaticallyOption site:lists.apple.com
yields 36 results. There's probably several duplicates but it give you
a head start
Hmmm. When I tried that this morning I only got 19. Among the additional 17,
I found this:
http://lists.apple.com/archives/cocoa-dev/2008/Aug/msg00767.html
Summary: There is no need to muck with NSPersistentDocument's built-in and
bug-free Persistence Stack. Happy Day! All you do is override
-[NSPersistentDocument initWithContentsOfURL:ofType:error:]. I submitted
document feedback suggesting this to the Core Data Model Versioning and Data
Migration Programming Guide.
Thanks, Matthew.
The code in that post had issues and didn't quite work, so I fixed it up and it
now seems to just work now for all three cases (1) oldest docs saved with old
model (2) old docs with new model (3) new docs. In case (1) the old file
remains with a tilde suffix, as expected. In case (3), the method doesn't even
run. But when it does, it handles errors properly :)
So, the answer to the question: How to enable Default Automatic Migration in a
Core Data document-based app, is...
Simply drop the following override into the NSPersistentDocument subclass:
- (id)initWithContentsOfURL:(NSURL*)url
ofType:(NSString*)typeName
error:(NSError**)error_p {
// NSPersistentDocument's built-in Persistence Stack seems to create a store
// without setting the NSMigratePersistentStoresAutomaticallyOption, so
// automatic migration just doesn't work. The following code, which runs
// only for existing documents, works around that problem.
NSError* error = nil ;
NSArray* bundles = [NSArray arrayWithObject:[NSBundle mainBundle]] ;
NSManagedObjectModel* mergedMOM = [NSManagedObjectModel
mergedModelFromBundles:bundles] ;
NSPersistentStoreCoordinator *psc = [[NSPersistentStoreCoordinator alloc]
initWithManagedObjectModel:mergedMOM];
NSDictionary *optionsDictionary =
[NSDictionary dictionaryWithObject:[NSNumber numberWithBool:YES]
forKey:NSMigratePersistentStoresAutomaticallyOption];
id store = [psc addPersistentStoreWithType:NSSQLiteStoreType
configuration:nil
URL:url
options:optionsDictionary
error:error] ;
// If migrating the document from and older to the current model was
necessary,
// it is now all done! The addPersistentStoreWithType: will have
renamed the
// old file with a tilde on the end and created a new, migrated file at the
given
// URL. So now, when we invoke super, it will open the new file and just
work.
// Very nice.
if (store) {
self = [super initWithContentsOfURL:url
ofType:typeName
error:error] ;
// The above method will return nil if it fails.
}
else {
[self release] ;
self = nil ;
}
if (!self error_p) {
*error_p = error ;
}
return self;
}
___
Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)
Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com
Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com
This email sent to arch...@mail-archive.com
