如何在运行时从NSManagedObjectModel生成Core Data访问器类文件（.m / .h文件）？

Question

I have an NSManagedObjectModel that I can generate at runtime but can't use it at runtime because I need the class files for the entities.

How can I generate these classes, and maybe stick them in an NSBundle to load them at runtime?

Thanks!

Answer 1

The best solution is to add Protocols.
You do not need the implementation for the managed object class.

@protocol NSManagedObjectProtocol <NSObject>
//Add NSManagedObject methods here. Like:
- (id)initWithEntity:(NSEntityDescription *)entity insertIntoManagedObjectContext:(NSManagedObjectContext *)context
@end

@protocol Person <NSManagedObjectProtocol>
@property (nonatomic, retain) NSString *name;
@property (nonatomic, retain) NSDate *birthDate;
@end

Use the protocol to access your objects.
This code would exist in some kind of manager:

NSManagedObjectContext *context = //Get the context.
NSError *error = nil;
id<Person> p = [NSEntityDescription insertNewObjectForEntityForName:@"Person" inManagedObjectContext:context];
[p setName:@"PersonName"];
if ([context save:&error]) {
    //Handle error
}