Handling Push Notifications in iOS

Overview

MobileFirst-provided Notifications API can be used in order to register & unregister devices, and subscribe & unsubscribe to tags. In this tutorial, you will learn how to handle push notification in iOS applications using Swift.

For information about Silent or Interactive notifications, see:

• Silent notifications
• Interactive notifications

Prerequisites:

• Make sure you have read the following tutorials:
  • Push Notifications Overview
  • Setting up your MobileFirst development environment
  • Adding the Mobile Foundation SDK to iOS applications
• MobileFirst Server to run locally, or a remotely running MobileFirst Server.
• MobileFirst CLI installed on the developer workstation

Jump to:

• Notifications configuration
• Notifications API
• Handling a push notification

Notifications Configuration

Create a new Xcode project or use and existing one. If the MobileFirst Native iOS SDK is not already present in the project, follow the instructions in the Adding the Mobile Foundation SDK to iOS applications tutorial.

Adding the Push SDK

1. Open the project’s existing podfile and add the following lines:

   use_frameworks!
   
   platform :ios, 8.0
   target "Xcode-project-target" do
        pod 'IBMMobileFirstPlatformFoundation'
        pod 'IBMMobileFirstPlatformFoundationPush'
   end
   
   post_install do |installer|
        workDir = Dir.pwd
   
        installer.pods_project.targets.each do |target|
            debugXcconfigFilename = "#{workDir}/Pods/Target Support Files/#{target}/#{target}.debug.xcconfig"
            xcconfig = File.read(debugXcconfigFilename)
            newXcconfig = xcconfig.gsub(/HEADER_SEARCH_PATHS = .*/, "HEADER_SEARCH_PATHS = ")
            File.open(debugXcconfigFilename, "w") { |file| file << newXcconfig }
   
            releaseXcconfigFilename = "#{workDir}/Pods/Target Support Files/#{target}/#{target}.release.xcconfig"
            xcconfig = File.read(releaseXcconfigFilename)
            newXcconfig = xcconfig.gsub(/HEADER_SEARCH_PATHS = .*/, "HEADER_SEARCH_PATHS = ")
            File.open(releaseXcconfigFilename, "w") { |file| file << newXcconfig }
        end
   end
   

   • Replace Xcode-project-target with the name of your Xcode project’s target.
2. Save and close the podfile.
3. From a Command-line window, navigate into to the project’s root folder.
4. Run the command pod install
5. Open project using the .xcworkspace file.

Notifications API

MFPPush Instance

All API calls must be called on an instance of MFPPush. This can be done by using a var in a view controller such as var push = MFPPush.sharedInstance();, and then calling push.methodName() throughout the view controller.

Alternatively you can call MFPPush.sharedInstance().methodName() for each instance in which you need to access the push API methods.

Challenge Handlers

If the push.mobileclient scope is mapped to a security check, you need to make sure matching challenge handlers exist and are registered before using any of the Push APIs.

Learn more about challenge handlers in the credential validation tutorial.

Client-side

Initialization

Initialization is required for the client application to connect to MFPPush service.

• The initialize method should be called first before using any other MFPPush APIs.
• It registers the callback function to handle received push notifications.

MFPPush.sharedInstance().initialize();

Is push supported

Checks if the device supports push notifications.

let isPushSupported: Bool = MFPPush.sharedInstance().isPushSupported()

if isPushSupported {
    // Push is supported
} else {
    // Push is not supported
}

Register device & send device token

Register the device to the push notifications service.

MFPPush.sharedInstance().registerDevice(nil) { (response, error) -> Void in
    if error == nil {
        self.enableButtons()
        self.showAlert("Registered successfully")
        print(response?.description ?? "")
    } else {
        self.showAlert("Registrations failed.  Error \(error?.localizedDescription)")
        print(error?.localizedDescription ?? "")
    }
}

MFPPush.sharedInstance().sendDeviceToken(deviceToken)

Note: This is typically called in the AppDelegate in the didRegisterForRemoteNotificationsWithDeviceToken method.

Get tags

Retrieve all the available tags from the push notification service.

MFPPush.sharedInstance().getTags { (response, error) -> Void in
    if error == nil {
        print("The response is: \(response)")
        print("The response text is \(response?.responseText)")
        if response?.availableTags().isEmpty == true {
            self.tagsArray = []
            self.showAlert("There are no available tags")
        } else {
            self.tagsArray = response!.availableTags() as! [String]
            self.showAlert(String(describing: self.tagsArray))
            print("Tags response: \(response)")
        }
    } else {
        self.showAlert("Error \(error?.localizedDescription)")
        print("Error \(error?.localizedDescription)")
    }
}

Subscribe

Subscribe to desired tags.

var tagsArray: [String] = ["Tag 1", "Tag 2"]

MFPPush.sharedInstance().subscribe(self.tagsArray) { (response, error)  -> Void in
    if error == nil {
        self.showAlert("Subscribed successfully")
        print("Subscribed successfully response: \(response)")
    } else {
        self.showAlert("Failed to subscribe")
        print("Error \(error?.localizedDescription)")
    }
}

Get subscriptions

Retrieve tags the device is currently subscribed to.

MFPPush.sharedInstance().getSubscriptions { (response, error) -> Void in
   if error == nil {
       var tags = [String]()
       let json = (response?.responseJSON)! as [AnyHashable: Any]
       let subscriptions = json["subscriptions"] as? [[String: AnyObject]]
       for tag in subscriptions! {
           if let tagName = tag["tagName"] as? String {
               print("tagName: \(tagName)")
               tags.append(tagName)
           }
       }
       self.showAlert(String(describing: tags))
   } else {
       self.showAlert("Error \(error?.localizedDescription)")
       print("Error \(error?.localizedDescription)")
   }
}

Unsubscribe

Unsubscribe from tags.

var tags: [String] = {"Tag 1", "Tag 2"};

// Unsubscribe from tags
MFPPush.sharedInstance().unsubscribe(self.tagsArray) { (response, error)  -> Void in
    if error == nil {
        self.showAlert("Unsubscribed successfully")
        print(String(describing: response?.description))
    } else {
        self.showAlert("Error \(error?.localizedDescription)")
        print("Error \(error?.localizedDescription)")
    }
}

Unregister

Unregister the device from push notification service instance.

MFPPush.sharedInstance().unregisterDevice { (response, error)  -> Void in
   if error == nil {
       // Disable buttons
       self.disableButtons()
       self.showAlert("Unregistered successfully")
       print("Subscribed successfully response: \(response)")
   } else {
       self.showAlert("Error \(error?.localizedDescription)")
       print("Error \(error?.localizedDescription)")
   }
}

Handling a push notification

Push notifications are handled by the native iOS framework directly. Depending on your application lifecyle, different methods will be called by the iOS framework.

For example if a simple notification is received while the application is running, AppDelegate’s didReceiveRemoteNotification will be triggered:

func application(_ application: UIApplication, didReceiveRemoteNotification userInfo: [AnyHashable: Any]) {
    print("Received Notification in didReceiveRemoteNotification \(userInfo)")
    // display the alert body
      if let notification = userInfo["aps"] as? NSDictionary,
        let alert = notification["alert"] as? NSDictionary,
        let body = alert["body"] as? String {
          showAlert(body)
        }
}

Learn more about handling notifications in iOS from the Apple documentation

Sample application

Click to download the Xcode project.

Sample usage

Follow the sample’s README.md file for instructions.