通信通知 Communication Notifications 的实现 (iOS 15+)

WWDC 2021 苹果在 iOS 15 系统中对通知做了很多改变, 让通知更加个性化.

这里只有讨论通信通知 Communication Notifications, 苹果自带的很多应用, 以及第三方App 飞书, 都使用了这个通知功能。

通信通知 Communication Notifications 简介

iOS 15系统后, Apple 添加了通信通知的功能。这些通知将包含发送它们的联系人的头像，并且可以与 SiriKit 集成，以便 Siri 可以智能地根据常用联系人提供通信操作的快捷方式和建议。

图例:

通信通 Communication Notifications 具体实现:

要使用通信通知，App 需要在 Xcode 中将通信通知功能添加到其应用程序，并在应用程序通知服务扩展中实现 UNNotificationContentProviding 协议。

1.首先将以下键值添加到主应用程序 Info.plist 文件中

NSUserActivityTypes (Array)- INStartCallIntent- INSendMessageIntent

具体位置如图所示:

2.在 `Xcode` -> `Capabilities` 中添加 `Communication Notifications` 功能

如图所示:

3.添加 `Notification Service Extension` 扩展

大多数社交媒体通知都是从服务器发送到 Apple 的 APN 服务器，然后再发送到设备。
我们需要使用通知服务扩展, 该扩展用于处理通知，然后将它们显示在屏幕上。

首先，将扩展Notification Service Extension 添加到项目中

然后将以下键和值添加到 Notification Service Extension 扩展 Info.plist 中

4.在 `Notification Service Extension` 扩展下 `NotificationService` 文件中, 重写 `didReceive` 方法

Apple APN 服务器每次在通知出现在用户屏幕上之前，都会调用此方法

初始代码如下:

import UIKit
import Intents
import UserNotificationsclass NotificationService: UNNotificationServiceExtension {var contentHandler: ((UNNotificationContent) -> Void)?var bestAttemptContent: UNMutableNotificationContent?override func didReceive(_ request: UNNotificationRequest, withContentHandler contentHandler: @escaping (UNNotificationContent) -> Void) {if let bestAttemptContent = bestAttemptContent {// ...}}
}

我们可以通过使用 INPerson或INSendMessageIntent创建此信息将其添加到您的推送通知消息中

具体实现代码如下:

class NotificationService: UNNotificationServiceExtension {var contentHandler: ((UNNotificationContent) -> Void)?var bestAttemptContent: UNMutableNotificationContent?override func didReceive(_ request: UNNotificationRequest, withContentHandler contentHandler: @escaping (UNNotificationContent) -> Void) {self.contentHandler = contentHandlerbestAttemptContent = (request.content.mutableCopy() as? UNMutableNotificationContent)if let bestAttemptContent = bestAttemptContent {// Modify the notification content here...// 获取通信消息if let senderAccountID = bestAttemptContent.userInfo["sender_id"] as? String,// 发送者名称let senderName = bestAttemptContent.userInfo["sender_name"] as? String,// 发送者图像url地址let senderImageURLString = bestAttemptContent.userInfo["sender_image_url"] as? String,// 发送者昵称let senderDisplayName = bestAttemptContent.userInfo["sender_nickname"] as? String,// 通信idlet chatSessionID = bestAttemptContent.userInfo["chat-session_id"] as? String{// Here you need to download the image data from the URL.self.getMediaAttachment(for: senderImageURLString) { image inguard let groupIcon = image else {contentHandler(bestAttemptContent)return}let avatar = INImage(imageData: groupIcon.pngData()!)// 消息发送方let messageSender = INPerson(personHandle: INPersonHandle(value: nil, type: .unknown),nameComponents: try? PersonNameComponents(senderName),displayName: senderDisplayName,image: avatar,contactIdentifier: nil,customIdentifier: senderAccountID,isMe: false,suggestionType: .none)// 消息接收方let mePerson = INPerson(personHandle: INPersonHandle(value: "", type: .unknown),nameComponents: nil,displayName: nil,image: nil,contactIdentifier: nil,customIdentifier: nil,isMe: true,suggestionType: .none)let intent = INSendMessageIntent(recipients: [mePerson, messageSender],outgoingMessageType: .outgoingMessageText,content: bestAttemptContent.body,speakableGroupName: INSpeakableString(spokenPhrase: senderDisplayName),conversationIdentifier: chatSessionID,serviceName: nil,sender: messageSender,attachments: nil)intent.setImage(avatar, forParameterNamed: \.speakableGroupName)let interaction = INInteraction(intent: intent, response: nil)interaction.direction = .incominginteraction.donate(completion: nil)do {let messageContent = try request.content.updating(from: intent)contentHandler(messageContent)} catch {print(error.localizedDescription)contentHandler(bestAttemptContent)}}}contentHandler(bestAttemptContent)}}override func serviceExtensionTimeWillExpire() {// Called just before the extension will be terminated by the system.// Use this as an opportunity to deliver your "best attempt" at modified content, otherwise the original push payload will be used.if let contentHandler = contentHandler, let bestAttemptContent =  bestAttemptContent {contentHandler(bestAttemptContent)}}
}

使用到的工具扩展, 包含图片下载和本地保存

extension NotificationService {// 保存图片到本地 并返回 本地 url 地址private func saveImageAttachment(image: UIImage, forIdentifier identifier: String) -> URL? {// 1 获取临时文件夹let tempDirectory = URL(fileURLWithPath: NSTemporaryDirectory())// 2 拼接文件路径let directoryPath = tempDirectory.appendingPathComponent(ProcessInfo.processInfo.globallyUniqueString,isDirectory: true)do {// 3 如果文件夹不存在 创建文件夹try FileManager.default.createDirectory(at: directoryPath,withIntermediateDirectories: true,attributes: nil)// 4 文件地址URLlet fileURL = directoryPath.appendingPathComponent(identifier)// 5 文件二进制guard let imageData = image.pngData() else {return nil}// 6 保存二进制文档到本地路径try imageData.write(to: fileURL)return fileURL} catch {return nil}}//  通过本地 url 地址 获取图片资源private func getMediaAttachment(for urlString: String, completion: @escaping (UIImage?) -> Void) {// 1guard let url = URL(string: urlString) else {completion(nil)return}// 2 通过远程图片URL下载图片downloadImage(forURL: url) { result in// 3guard let image = try? result.get() else {completion(nil)return}// 4completion(image)}}// 通过远程图片url地址 下载图片文件public enum DownloadError: Error {case emptyDatacase invalidImage}private func downloadImage(forURL url: URL, completion: @escaping (Result<UIImage, Error>) -> Void) {let task = URLSession.shared.dataTask(with: url) { data, response, error inif let error = error {completion(.failure(error))return}guard let data = data else {completion(.failure(DownloadError.emptyData))return}guard let image = UIImage(data: data) else {completion(.failure(DownloadError.invalidImage))return}completion(.success(image))}task.resume()}
}

额外补充: 通知 Notifications 实现附件图片展示

在回调 bestAttemptContent 之前, 给它设置 `attachments`属性即可

@available(iOS 10.0, *)
open class UNMutableNotificationContent : UNNotificationContent {/// ...// Optional array of attachments.open var attachments: [UNNotificationAttachment]/// ...
}

核心代码如下:

// 创建图片附件
let imageAttachment = try? UNNotificationAttachment(identifier: "image",url: "图片本地路径, 和上面设置 Avatar 地址一样",options: nil)// 赋值给 bestAttemptContent
if let imageAttachment = imageAttachment {bestAttemptContent.attachments = [imageAttachment]
}// 回调出去
contentHandler(bestAttemptContent)