Swift-如何在后台获取某些静默通知，在前台获取其他静默通知？

Question

In my app users can send each other chat messages and place orders for things (similar to OfferUp). I use silent push notifications and I receive them with no problem.

What I want to do is have it so when an userA send userB an order, a silent notification will come through wether userB is in the background or foreground .

But when userA sends userB a message, the silent notification should only come through if userB is in the background only. There's no need for the notification if userB is in the foreground.

I use an orderId for the order and messageId for the messages.

I get the the silent notifications in App Delegate's :

func userNotificationCenter(_ center: UNUserNotificationCenter, willPresent notification: UNNotification, withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void) {

    let userInfo = notification.request.content.userInfo

    // I can parse userInfo and get the messageId or the orderId

    guard let userInfo = userInfo as? [String: Any] else { return }

    if let orderId = userInfo["orderId"] as? String {
    }

    if let messageId = userInfo["messageId"] as? String {
    }
}

OrderVC:

func orderWasPlacedNowSendNotification() {

    let urlString = "https://fcm.googleapis.com/fcm/send"

    var apsDict = [String: Any]()
    apsDict.updateValue(title, forKey: "title")
    apsDict.updateValue(body, forKey: "body")
    apsDict.updateValue(1, forKey: "content-available")

    var dataDict = [String: Any]()
    dataDict.updateValue(orderId, forKey: "orderId") // orderId

    var paramDict = [String: Any]()
    paramDict.updateValue(apsDict, forKey: "notification")
    paramDict.updateValue(toToken, forKey: "to")

    paramDict.updateValue(dataDict, forKey: "data")

    let request = NSMutableURLRequest(url: url as URL)
    URLSession.shared.dataTask(with: request as URLRequest) ...
}

MessageVC:

func messageWasSentNowSendNotification() {

    let urlString = "https://fcm.googleapis.com/fcm/send"

    var apsDict = [String: Any]()
    apsDict.updateValue(title, forKey: "title")
    apsDict.updateValue(body, forKey: "body")
    apsDict.updateValue(1, forKey: "content-available")

    var dataDict = [String: Any]()
    dataDict.updateValue(messageId, forKey: "messageId") // messageId

    var paramDict = [String: Any]()
    paramDict.updateValue(apsDict, forKey: "notification")
    paramDict.updateValue(toToken, forKey: "to")

    paramDict.updateValue(dataDict, forKey: "data")

    let request = NSMutableURLRequest(url: url as URL)
    URLSession.shared.dataTask(with: request as URLRequest) ...
}

How can I separate the silent notifications?

Answer 1

According to your logic you need to return inside willPresent

if application.applicationState == .active {   
    completionHandler([])  // no alert/sound
}
else if application.applicationState == .background  { 
     completionHandler([.sound,.alert]) // alert with sound
} 

you can add more checks as you need but last to either return any of the completions for slient/alert respectively