Can you save an array of images in core data?

Question

I know you can save one by using the binary data property of an entity but is it possible to save multiple?

you can save one by using this:

UIImageJPEGRepresentation(image: UIImage)

you can save it and then transform it into an image again with

UIImage(data: ____)

but can I transform an array full of images into binary data?

If you can't with core data, any other ways I can do it?

BTW, the image array is full of user taken image saved on the device..

Thanks for all the helpers!

Answer 1

convert your array to NSMutableArray and archive it as NSData

var imgArray = [UIImage]();

var CDataArray = NSMutableArray();

for img in imgArray{
    let data : NSData = NSData(data: UIImagePNGRepresentation(img))
    CDataArray.addObject(data);
}

//convert the Array to NSData
//you can save this in core data
var coreDataObject = NSKeyedArchiver.archivedDataWithRootObject(CDataArray);

after pulling from CData, extract data:

//extract:
if let mySavedData = NSKeyedUnarchiver.unarchiveObjectWithData(coreDataObject) as? NSArray{
    //extract data..
}

Swift 5

There are some methods deprecated now. The following code is working in Swift 5:

func coreDataObjectFromImages(images: [UIImage]) -> Data? {
    let dataArray = NSMutableArray()
    
    for img in images {
        if let data = img.pngData() {
            dataArray.add(data)
        }
    }
    
    return try? NSKeyedArchiver.archivedData(withRootObject: dataArray, requiringSecureCoding: true)
}

func imagesFromCoreData(object: Data?) -> [UIImage]? {
    var retVal = [UIImage]()

    guard let object = object else { return nil }
    if let dataArray = try? NSKeyedUnarchiver.unarchivedObject(ofClass: NSArray.self, from: object) {
        for data in dataArray {
            if let data = data as? Data, let image = UIImage(data: data) {
                retVal.append(image)
            }
        }
    }
    
    return retVal
}