An NSValueTransformer to convert images to/from serialized PNGs (for CoreData)

BPImageTransformer.h

//
//  BPImageTransformer.h
//  Skates
//
//  Created by Jon Olson on 2/3/10.
//  Copyright 2010 Ballistic Pigeon, LLC. All rights reserved.
//

#import <Foundation/Foundation.h>


@interface BPImageTransformer : NSValueTransformer {

}

+ (void)registerValueTransformer;

@end

BPImageTransformer.m

//
//  BPImageTransformer.m
//  Skates
//
//  Created by Jon Olson on 2/3/10.
//  Copyright 2010 Jon Olson. All rights reserved.
//

#import "BPImageTransformer.h"


@interface BPImageTransformer (Private)

@end

@implementation BPImageTransformer

+ (void)registerValueTransformer {
	[NSValueTransformer setValueTransformer:[[[self alloc] init] autorelease] forName:@"BPImageTransformer"];
}

#pragma mark -
#pragma mark NSValueTransformer implementation

+ (BOOL)allowsReverseTransformation {
	return YES;
}

+ (Class)transformedValueClass {
	return [NSData class];
}

#pragma mark -
#pragma mark Image transformation

- (id)transformedValue:(id)value {
	return UIImagePNGRepresentation(value);
}

- (id)reverseTransformedValue:(id)value {
	return [UIImage imageWithData:value];
}

@end