nsvaluetransformer

Is an NSValueTransform subclass a good choice for displaying Core Data attributes into UI views displaying: A number string like (0,1,2,3,etc) into a string such as (Pending, Completed, Frozen, In progress, etc) A number string like (0,1) into a app-based image (red.png if 0, green.png if 1) Here's what Core Data displays for the two attributes, timer and status: Here is what I want to be displayed instead, without changing the values in Core Data: If not to use NSValueTransformer, in what other way is this possible? I do not want to see the data permanently converted, only for the benefit of

I want to encrypt some core-data columns with help of an NSValueTransformer. The idea is, that I use data-type transformable and define some transformer for my datatypes. Inside the transformation-methods I want to encrypt/ decrypt the value. I defined a transformer that does actually nothing - the crypto-stuff is currently not implemented. @implementation StringCryptoTransformer + (Class)transformedValueClass { return [NSString class]; } + (BOOL)allowsReverseTransformation { return YES; } - (NSString*)transformedValue:(id)value { NSLog(@"Transformer: %@",value); if([value isKindOfClass:

I'm experimenting with encrypting data with Core Data and CommonCrypto. I am trying to use a NSValueTransformer to lazily encrypt and decrypt. However when I'm now trying save the encrypted data to the persistent store coordinator, it fails. Every time im trying to save my data to the database, it gives me: -[__NSCFString bytes]: unrecognized selector sent to instance I'm sure it's some sort of database and NSManagedObject mismatch, but I can't figure it out. I feel it's probably rather simple, but I can't find the solution. My code: NSValueTransformer class TryHardEncryption:

There's this Transformable data type for attributes. What is it good for? Are there good examples? I'd like to play around with this. So after searching a while I came across this: NSValueTransformer. Seems to be something I need for this. So how would I get started with this? For example, if I wanted to store an UIColor object, would I make an transformer for that? What exactly is this thing transforming to or from? An NSData? And must the object which I pass to the transformer follow any protocol? Brad Larson Transformable attributes are useful for storing nonstandard object types within

I'm trying to put entities in a Core Data store that each have non-standard data types - one is an NSDocument and the other is an NSURL. I get that within the .xcdatamodeld I need to declare them as Transformable. And I think I need to add something that implements NSValueTransformer to turn them into NSData (... or is there a default transformer that will do that automatically?) I think the question should be simple to answer: where do I implement it? I haven't found an explicit example of doing this in Swift. There's an Objective-C example but the separation of .h and .m files makes it