Notification Service Extension - Issue about showing image on push notification

Question

I added 'Notification Service Extension' in my project, and want to show image on push notification.

In code, first I downloaded the image from the url with 'downloadTask' method of URLSessionDownloadTask.
And it was saved successfully in the url like

'file://private/var/mobile/Containers/Data/..../tmp/CFNetworkDownload_fads.tmp'

I don't know exactly what I have to do after saving image.

After I downloaded the image successfully and saved in tmp directory, I tried with some options.

First, I made a UNNotificationAttachment instance without any options.

Result is fail, I think it couldn't know about attachment's type. So it couldn't do right things.

Second, I made a same instance with options, I took the Uniform Type Identifier value "public.jpeg" to the key 'UNNotificationAttachmentOptionsTypeHintKey'.

It was success but I have some curious thing. I write about it after explain third try.

Third, I tried with only change the value from "public.jpeg" to "public.png"

It was success too.

The thing I wondered is why the second and third tries were success.

They show image regardless of it's actual image format type.(jpeg, png)

I took the option as "public.jpeg", and I send a url end with '.png' extension, but it shows that image successfully.

The opposite was also success.

I don't have knowledge about image format type, so I can't understand why it works.

I would appreciate your explanation.

// Download image
guard let url = URL(string: urlString) else {
            completion(nil, NSError(domain: "error", code: -1, userInfo: nil))
            return
        }

        let task = URLSession.shared.downloadTask(with: url, completionHandler: { url, _, error in
            completion(url, error)
        })

        task.resume()

// Make UNNotificationAttachment with option (TypeHintKey: "public.png")
if let imageAttachment = try? UNNotificationAttachment(identifier: "image", url: url, options: [UNNotificationAttachmentOptionsTypeHintKey: "public.png"]) {
                            mutableContent.attachments = [imageAttachment]
                            contentHandler(mutableContent)
                        } else {
                            contentHandler(mutableContent)
                        }

// Make UNNotificationAttachment with option (TypeHintKey: "public.jpeg")
if let imageAttachment = try? UNNotificationAttachment(identifier: "image", url: url, options: [UNNotificationAttachmentOptionsTypeHintKey: "public.jpeg"]) {
                            mutableContent.attachments = [imageAttachment]
                            contentHandler(mutableContent)
                        } else {
                            contentHandler(mutableContent)
                        }

// Make UNNotificationAttachment without option
if let imageAttachment = try? UNNotificationAttachment(identifier: "image", url: url, options: nil) {
                            mutableContent.attachments = [imageAttachment]
                            contentHandler(mutableContent)
                        } else {
                            contentHandler(mutableContent)
                        }

Engineer Muhammad Naeem Akram Engineer Muhammad Naeem Akram · Accepted Answer · 2019-06-27T10:01:00

Welcome Sohn,

func currentUserImage(){

                let headers = ["Authorization":"Bearer \(UserDefaults.standard.string(forKey: "token")!)"]
                Alamofire.request(Constants.currentUserImageURL,method: .get,  encoding: JSONEncoding.default,  headers: headers).responseJSON { response in
                    if response.result.isSuccess{
                        let currentUserResponce : JSON = JSON(response.result.value!)

                        let first_name = currentUserResponce["data"]["first_name"].stringValue
                        let last_name = currentUserResponce["data"]["last_name"].stringValue
                        let username = "\(first_name) \(last_name)"
                        let url = URL(string: "\(currentUserResponce["data"]["photo_thumb"].stringValue)")
                        let currentUserId = currentUserResponce["data"]["id"].intValue

                        UserDefaults.standard.set(currentUserId, forKey: "currentUserID")
                        self.listenForChanges()

                        DispatchQueue.global().async {
                            if let data = try? Data( contentsOf:url!)
                            {
                                DispatchQueue.main.async {
                                    self.currentUser.image = UIImage( data:data)
                                }
                            }
                        }
                    }
                }
}

Here this is the way how to take Image URL from Server and show it in ImageView.

Hope you got your point from this code.

Notification Service Extension - Issue about showing image on push notification

1 Answers