Make UIColor Codable

README.md

Here's a solution which I originally wrote for StackExchange which will work for any color in any color space.

It's relatively easy to use:

let color = UIColor.label

let encoder = JSONEncoder()
let encodedData = try encoder.encode(color.codable())

let decoder = JSONDecoder()
let decodedColor = try decoder.decode(CodableColor.self, from: encodedData).color

Of course, you can also use it as any other Swift codable, like in a struct with auto-synthesized codable conformance:

struct Foo: Codable {
    let color: CodableColor

    init(color: UIColor) {
        self.color = CodableColor(color: color)
    }
}

let fooInstance = Foo(color: .systemPurple)

let encoder = JSONEncoder()
let encodedData = try encoder.encode(fooInstance)

let decoder = JSONDecoder()
let decodedFoo = try decoder.decode(Foo.self, from: encodedData)

This will work with NSColor as well.

LICENSE.txt

                 BLUE HUSKY LICENSE 0 - PUBLIC DOMAIN - OPUS 7

0: LAYMAN'S TERMS
   This section is meant to explain the purpose of this License in Layman's
terms, and should thusly never be seen as legally binding. This disclaimer does
not apply to further sections of this License.

 1. This is no one's product and is in the public domain
 2. You're not responsible for any bad things that might happen because someone
    used this product
 3. If you use someone else's stuff, it's still theirs


1: DECLARATION OF CREATION
   This product was made by Ben Leggiero in 2019

   Ben Leggiero may be reached at [email protected]


2: DEFINITIONS
 - "License": this text.
 - "Product": the product with which this License was distributed, and any
   assets necessary for its use.
 - "Licensor": any entity or entities involved in distribution of the Product
   and of this License.


3: NOTICE OF PERMISSIONS
 1. Permission is hereby granted to any entity obtaining a copy of the Product,
    to use, copy, modify, redistribute, sublicense, sell copies of, and/or
    otherwise handle the Product, and to permit entities to whom the Product is
    furnished to also do so, given the following conditions are obeyed:
   a. The above copyright notice and this permission notice shall be included
      in all copies and/or substantial portions of the Product.
   b. This License shall be blatantly provided, unmodified, along with the
      Product.
 2. The Licensor reserves the right to edit this License at any time under the
    terms of BH-1-PS, given the following conditions are obeyed:
   a. The Licensor agrees to increment the Opus number of this License to
      correspond with version changes.
   b. The Licensor agrees to never publish two or more versions of this License
      under the same Opus number.
   c. The Licensor agrees to notify the License's original author of any
      changes made to the License. If such author is not reasonably accessible,
      the Licensor agrees to notify any known authors which have previously
      contributed to the License.


4: REFUSAL OF OWNERSHIP
   The Licensor hereby refuses ownership, both fully and partially, of the
Product, and agrees to continue to refuse ownership so long as this License is
provided with the Product.

   If any part of the Product is covered under copyright, trademark,
intellectual property, or any other form of ownership, to the Licensors or any
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where local, state, provincial, federal, national, or any other law prohibits
such terms.


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   THE PRODUCT IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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UIColor + Codable.swift

/// Allows you to use Swift encoders and decoders to process UIColor
public struct CodableColor {

    /// The color to be (en/de)coded
    let color: UIColor
}



extension CodableColor: Encodable {

    public func encode(to encoder: Encoder) throws {
        let nsCoder = NSKeyedArchiver(requiringSecureCoding: true)
        color.encode(with: nsCoder)
        var container = encoder.unkeyedContainer()
        try container.encode(nsCoder.encodedData)
    }
}



extension CodableColor: Decodable {

    public init(from decoder: Decoder) throws {
        var container = try decoder.unkeyedContainer()
        let decodedData = try container.decode(Data.self)
        let nsCoder = try NSKeyedUnarchiver(forReadingFrom: decodedData)
        self.color = try UIColor(coder: nsCoder).unwrappedOrThrow()
        // `unwrappedOrThrow()` is from OptionalTools: https://github.com/RougeWare/Swift-Optional-Tools
        
        // You can use this if you don't want to use OptionalTools:
        /*
        guard let color = UIColor(coder: nsCoder) else {
            
            struct UnexpectedlyFoundNilError: Error {}
            
            throw UnexpectedlyFoundNilError()
        }
        
        self.color = color
        */
    }
}



public extension UIColor {
    func codable() -> CodableColor {
        return CodableColor(color: self)
    }
}

Thanks for the code - very useful.

Instead of:
let encodedData = try encoder.encode(color.codable())

I think this should be:
let encodedData = try encoder.encode(CodableColor(color: color))

Thanks for reminding me, @scottcarter! I forgot to finish this off with an extension method. But yes, you're correct; that was the proper way to use it before the edit I just made.