How to properly send an image to CloudKit as CKAsset?

Question

I have an image (UIImage and it\'s url too) and I\'m trying to send it to CloudKit as a CKAsset but I\'m having this error: Terminating app due to uncaught exception \

Answer 1

I did something a tad different: I made a class that you can use in multiple places, and thanks to the fact that Swift has reinitialization that works (unlike C++), it cleans up after itself:

//
//  ImageAsset.swift
//

import CloudKit
import UIKit

class ImageAsset {

    let image:UIImage

    var url:NSURL?

    var asset:CKAsset? {
        get {
            let data = UIImagePNGRepresentation(self.image)
            self.url = NSURL(fileURLWithPath: NSTemporaryDirectory()).URLByAppendingPathComponent(NSUUID().UUIDString+".dat")
            if let url = self.url {
                do {
                    try data!.writeToURL(url, options: [])
                } catch let e as NSError {
                    print("Error! \(e)")
                }
                return CKAsset(fileURL: url)
            }
            return nil
        }
    }

    init(image:UIImage){
        self.image = image
    }

    deinit {
        if let url = self.url {
            do {
                try NSFileManager.defaultManager().removeItemAtURL(url) }
            catch let e {
                print("Error deleting temp file: \(e)")
            }
        }
    }


}

Here's a unit test that exercises it (presumes there is an image named stopwatch in the test target):

//
//  ImageExtensionTests.swift
//

import CloudKit
import XCTest
@testable import BudgetImpactEstimator

class ImageExtensionTests: XCTestCase {

    let testImageName = "stopwatch" // provide the name of an image in test bundle
    override func setUp() {
        super.setUp()
        // Put setup code here. This method is called before the invocation of each test method in the class.
    }

    override func tearDown() {
        // Put teardown code here. This method is called after the invocation of each test method in the class.
        super.tearDown()
    }

    func testConvertingImageToAsset() {
        guard let image = UIImage(named: self.testImageName) else {
            XCTFail("failed to load image")
            return
        }
        let imageAsset = ImageAsset(image: image)
        XCTAssertNotNil(imageAsset)

        guard let asset = imageAsset.asset else {
            XCTFail("failed to get asset from image")
            return
        }

        print("constructed asset: \(asset)")
    }


}

Was originally going to do it as an extension on UIImage but then the deist made me move to a class.