Unnotificationattachment with Uiimage or Remote Url

UNNotificationAttachment with UIImage or Remote URL

1. create directory in tmp folder
2. write the NSData representation of the UIImage into the newly created directory
3. create the UNNotificationAttachment with url to the file in tmp folder
4. clean up tmp folder

I wrote an extension on UINotificationAttachment

extension UNNotificationAttachment {

    static func create(identifier: String, image: UIImage, options: [NSObject : AnyObject]?) -> UNNotificationAttachment? {
        let fileManager = FileManager.default
        let tmpSubFolderName = ProcessInfo.processInfo.globallyUniqueString
        let tmpSubFolderURL = URL(fileURLWithPath: NSTemporaryDirectory()).appendingPathComponent(tmpSubFolderName, isDirectory: true)
        do {
            try fileManager.createDirectory(at: tmpSubFolderURL, withIntermediateDirectories: true, attributes: nil)
            let imageFileIdentifier = identifier+".png"
            let fileURL = tmpSubFolderURL.appendingPathComponent(imageFileIdentifier)
            let imageData = UIImage.pngData(image)
            try imageData()?.write(to: fileURL)
            let imageAttachment = try UNNotificationAttachment.init(identifier: imageFileIdentifier, url: fileURL, options: options)
            return imageAttachment
        } catch {
            print("error " + error.localizedDescription)
        }
        return nil
    }
}

So to create UNUserNotificationRequest with UNUserNotificationAttachment from a UIImage you can simply do sth like this

let identifier = ProcessInfo.processInfo.globallyUniqueString
let content = UNMutableNotificationContent()
content.title = "Hello"
content.body = "World"
if let attachment = UNNotificationAttachment.create(identifier: identifier, image: myImage, options: nil) {
    // where myImage is any UIImage
    content.attachments = [attachment] 
}
let trigger = UNTimeIntervalNotificationTrigger(timeInterval: 120.0, repeats: false)
let request = UNNotificationRequest.init(identifier: identifier, content: content, trigger: trigger)
UNUserNotificationCenter.current().add(request) { (error) in
    // handle error
}

This should work since UNNotificationAttachment will copy the image file to an own location.

Attach image to notification given image URL

Your code downloads an image, parses it to create a UIImage, converts the image back to a block of PNG data, then writes this data to a temporary file.

You can skip the step where you create the UIImage and convert it back to a file.

Try using URLSession and URLDataTask:

let fileURL = ...
let task = URLSession.shared.dataTask(with: url) { (data, _, _) in
    do {
        try imageData.write(to: fileURL)
        let attachment = UNNotificationAttachment.create(identifier: key, image: myImage, options: nil)
        // call closure to call back with attachment and/or error
    }
    catch let ex {
        // call closure with error
    }
}
task.resume()

I've left out some error handling and other details, but this should give you the general idea of what's required to do it asynchronously. URLSessions use GCD to perform asynchronous networking.

UNNotificationAttachment failing to attach image

I have found the real issue behind it. In apple documentation it is written that the url should be a file url and because of which you might be facing issue.

To solve this I have added image to temporary directory and then added to UNNotificationAttachment .

Please find the code below. (For my use case I was getting an imageURL)

extension UNNotificationAttachment {
    /// Save the image to disk
    static func create(imageFileIdentifier: String, data: NSData, options: [NSObject : AnyObject]?) -> UNNotificationAttachment? {
        let fileManager = FileManager.default
        let tmpSubFolderName = ProcessInfo.processInfo.globallyUniqueString
        let tmpSubFolderURL = NSURL(fileURLWithPath: NSTemporaryDirectory()).appendingPathComponent(tmpSubFolderName, isDirectory: true)

        do {
            try fileManager.createDirectory(at: tmpSubFolderURL!, withIntermediateDirectories: true, attributes: nil)
            let fileURL = tmpSubFolderURL?.appendingPathComponent(imageFileIdentifier)
            try data.write(to: fileURL!, options: [])
            let imageAttachment = try UNNotificationAttachment.init(identifier: imageFileIdentifier, url: fileURL!, options: options)
            return imageAttachment
        } catch let error {
            print("error \(error)")
        }
        return nil
    }
}

data in the argument of this function is Data of image . Below is how did I call this method.

let imageData = NSData(contentsOf: url)
guard let attachment = UNNotificationAttachment.create(imageFileIdentifier: "img.jpeg", data: imageData!, options: nil) else { return  }
            bestAttemptContent?.attachments = [attachment]

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