This project is a "simple" abstract subclass of NSManagedObject to test objects to see if they are new entities or if similar entities exists.
At the moment it has a few limitations:
- Only one property can be used to test for uniqueness, at the moment this must conform to NSCopying, and respond correctly to isEqual: (ie. NSNumber,NSString)
- The objects are loaded (faulted) rather than just the unique ID value for each
- While it is multi-threaded, the search method does not return until the work is complete, however you could spin up a threaded MOC, and DIY.
- It has a obvious bottle neck in the of form a Lock around a mutable collection.
This is mainly a proof of concept, and a request for comments on how to improve the performance and the flexibility of the code.
Firstly you need to override the uniqueKeyPath and entityName methods to refect the unique keypath of your managedObject and entityName respectively.
Then where ever you import data you will call this method:
+ (NSArray *)allUniqueObjectsWith:(NSArray *)newObjects
uniqueKeyPath:(NSString *)aKeypath
managedObjectContext:(NSManagedObjectContext *)aMoc
With an array of new objects you wish to import, and the keypath to the property of each of the imported objects that you wish to compare against your presected keypath with your managedObject.
This method will return an NSArray of all of the objects that do not yet exist within the data store. With this information you can then prompt the user to approve them, add them, or quite frankly do whatever you please.
Copyright (C) <2013> <Jonathan Dalrymple>
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