A Swift class to manage image to data value transformations for use with Core Data

MNGImageToDataTransformer.swift

//
//  MNGImageToDataTransformer.swift
//  
//
//  Created by Tommie N. Carter, Jr., MBA on 9/11/15.
//  Copyright © 2015 MING Technology. All rights reserved.
//

import UIKit

class MNGImageToDataTransformer: NSValueTransformer {
    
    override class func allowsReverseTransformation () -> Bool {
        return true
    }
    override class func transformedValueClass () -> AnyClass {
        return NSData.classForCoder()
    }
    
    
    //NOTE: Can we consider using UIImageJPEGRepresentation for thumbnails
     override func transformedValue (value:AnyObject?) -> AnyObject? {
        return UIImagePNGRepresentation(value! as! UIImage)
    }
    override func reverseTransformedValue (value: AnyObject?) -> AnyObject? {
        
        return UIImage (data: value! as! NSData)
    }
    
}

class MNGThumbnailImageToDataTransformer: NSValueTransformer {
    
    override class func allowsReverseTransformation () -> Bool {
        return true
    }
    override class func transformedValueClass () -> AnyClass {
        return NSData.classForCoder()
    }
    
    
    //Use JPEG for low-resolution thumbnails
    override func transformedValue (value:AnyObject?) -> AnyObject? {
        return UIImageJPEGRepresentation((value! as! UIImage),  0.0)
    }
    override func reverseTransformedValue (value: AnyObject?) -> AnyObject? {
        
        return UIImage (data: value! as! NSData)
    }
    
}