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copied!<p>Have a look at this code I wrote recently, to cache an image in an NSManagedObject:</p> <p>First you define a <strong>transient property</strong> in your model (notice that if your transient property points to an object type other than those supported by CoreData you'll leave as "<code>Undefined</code>" in the model)</p> <p><img src="https://i.stack.imgur.com/GcW1v.png" alt="enter image description here"></p> <p>Then, you re-generate your NSManagedObject subclass for that entity or just add the new property manually, the header file should look like this:</p> <pre><code>@interface Card : NSManagedObject @property (nonatomic, retain) NSString * imagePath; @property (nonatomic, retain) NSString * name; @property (nonatomic, retain) NSNumber * order; @property (nonatomic, retain) NSString * displayName; @property (nonatomic, retain) UIImage *displayImage; @end </code></pre> <p>Here we change the class of the transient property to the actual class type </p> <p>e.g. <code>displayImage</code> type here is <code>UIImage</code>.</p> <p>In the implementation file (or an extension class) you implement the getter/setter for your transient property:</p> <pre><code>-(UIImage*)displayImage{ //Get Value [self willAccessValueForKey:@"displayImage"]; UIImage *img = (UIImage*)[self primitiveValueForKey:@"displayImage"]; [self didAccessValueForKey:@"displayImage"]; if (img == nil) { if ([self imagePath]) { //That is a non-transient property on the object img = [UIImage imageWithContentsOfFile:self.imagePath]; //Set Value [self setPrimitiveValue:img forKey:@"displayImage"]; } } return img; } </code></pre> <p>Hope that helps you.</p>

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