After some more searching I came to the following plan. 1. get the main context from another thread as follows:
AppDelegate *appDelegate = [[NSApplication sharedApplication] delegate]; NSManagedObjectContext *mainContext = [appDelegate managedObjectContext]; 2. use performSelectorOnMainThread to execute the fetch request: [mainContext performSelectorOnMainThread:@selector(executeFetchRequest:) withObject:fetchRequest waitUntilDone:YES]; However, performSelectorOnMainThread does not give a return value back, and the selector should really be executeFetchRequest:error: One way to solve this would be to use an NSInvocation, I think? Or maybe wrap the executeFetchRequest in another method, call performSelectorOnMainThread on it, and then use a notification to send the result back. Will try this later, does any of these approaches sound reasonable? - Koen. On Wed, Oct 17, 2012 at 12:25 PM, Koen van der Drift <koenvanderdr...@gmail.com> wrote: > I'm reading up on importing data into the CD store using multiple > contexts and threads.This article has already been very helpful: > http://www.duckrowing.com/2010/03/11/using-core-data-on-multiple-threads/ > Now if I have a local context on a separate thread to import my data, > how can I send a fetchrequest to the main context to see if a certain > entity already exists, and thus skip the import? I already have the > fetchrequest code, just trying to understand how to access the main > context form a separate thread. > > Thanks, > > - Koen. _______________________________________________ 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: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com