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    <p>I do not have that book, but I'll try to help...</p> <p>However, it does not look wrong to me. It looks like exactly what I would expect (assuming aPerson lives in a different context when setCurrentPerson is called). I'll try to walk through the code you posted. Maybe I can some how determine what your question is, and somehow provide an answer in the process. My comments are included in the code as, well, comments.</p> <pre><code>- (void)setCurrentPerson:(AWPerson *)aPerson { if( !aPerson ) { // The aPerson object we were given is nil, so get one in the // current editingContext. aPerson = [AWPerson randomPersonInManagedObjectContext:self.editingContext]; } else if( [aPerson managedObjectContext] != self.editingContext ) { // The aPerson object does not live in editingContext. However, apparently // we want to make sure it lives in the editingContext. Remember, each managed // that has been saved will have a permanent object-id. Any context can use // the object-id to fetch an object into its own ManagedObjectContext. self.title = @"Edit person"; aPerson = (id)[self.editingContext objectWithID:[aPerson objectID]]; // Now, aPerson will point to an object that lives in the MOC editingContext. // However, if it was not previously registered in that MOC, it will be returned // as a fault. This does not mean the object is not there, but this MOC has // not loaded its data. As soon as you cal a method that needs the data, // it will be faulted into memory. // One way, is to access any of its properties. NSLog(@"firstName = %@", [aPerson valueForKey:@"firstName"]); // You can query an object to see if it is a fault. NO means it's // not a fault, and the properties should all be in memory. YES, does not mean // the data is NOT in memory though... it could be in a cache... // You can manually fault the object into memory, but I would // suggest you read all the documentation before using this, because it has // side effects. Consider... if ([aPerson isFault]) { [self.editingContext refreshObject:aPerson mergeChanges:YES]; } // NOTE: In general, you just want the object management system itself // to manage faults. However, if you really want to see that your objects // are what they are supposed to be, you can do any of this to examine them. } [...] } </code></pre>
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