SmartValueTransformer.swift

//
//  SmartValueTransformer.swift
//  Panasonic IP setup
//
//  Created by Damiaan on 12/04/18.
//  Copyright © 2018 Devian. All rights reserved.
//

import Foundation

class SmartValueTransformer<Input, Output: AnyObject>: ValueTransformer {
	let forwardTransform: (Input) -> Output
	
	init(name: String, transformer: @escaping (Input) -> Output) {
		forwardTransform = transformer
		super.init()
		ValueTransformer.setValueTransformer(self, forName: NSValueTransformerName(rawValue: name))
	}
	
	override class func transformedValueClass() -> AnyClass {
		return Output.self
	}
	
	override func transformedValue(_ value: Any?) -> Any? {
		if let input = value as? Input {
			return forwardTransform(input)
		} else {
			return nil
		}
	}
}

class StringTransformer<Input>: SmartValueTransformer<Input, NSString> {
	init(name: String, transformer: @escaping (Input) -> String) {
		super.init(name: name) { transformer($0) as NSString }
	}
}