Receiving push notifications from Apple’s Push Notification and Google’s Firebase Cloud Messaging services
January 31, 2017 Allen Drennan
January 31, 2017 Allen Drennan
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In the previous article we demonstrated how to roll your own Google Firebase Cloud Messaging and Apple APNS push notifications from Delphi apps in a unified manner. This article continues the conversation about how to easily receive and consume them in your Delphi mobile app.
Introduction
If you are authoring a Delphi service for the cloud, you may have the need to send and receive push notifications from your service to your mobile client application. You could use an existing BAAS provider to accomplish this, but why pay for this when you can roll your own so easily with Delphi?
Delphi provides a base set of classes in the units FMX.PushNotification.Android and FMX.PushNotification.iOS that do most of the heavy lifting and allow you to easily consume remote push notifications. In this conversation we will be demonstrating a helper class that unifies the approach for both platforms, uses TMessage callbacks for notifications and device token changes and adds some new missing features.
For more information about us, our support and services visit the Для просмотра ссылки Войдиили Зарегистрируйся or the Для просмотра ссылки Войди или Зарегистрируйся.
The example contained here depends upon part of our Для просмотра ссылки Войдиили Зарегистрируйся.
Getting started on iOS
To receive push notifications on iOS you must:
Getting started on Android
To receive push notifications on Android you must:
For Android, we only need the Firebase Cloud Messaging API Key for our Delphi app.
TgoRemotePushReceiver class
The Для просмотра ссылки Войдиили Зарегистрируйся unifies the receiving of remote push notifications from both APNS and Firebase Cloud Messaging into a common class model.
When you receive a remote push notification message from Android or iOS, the following TMessage is fired:
Since we are receiving a JSON payload for both Android and iOS we can examine the content here. This is useful is we want to include our own custom content in the payload that is app specific. See our Для просмотра ссылки Войдиили Зарегистрируйся for a discussion about customizing the payload.
If your device token changes on Android or iOS, the following TMessage is fired:
The above message is fired initially when you device token is assigned after app startup. Due to the variances in the way device tokens are handled on iOS and Android this event could be immediate or delayed by the operating system.
As a developer you should also be prepared that the device token could change if your application is reinstalled, the operating system is updated as well as dynamically while your app is active.
Apple APNS quirks
On iOS Remote Push notification events are received only when your application is in the foreground or background. If your application is “force quit” also known as “terminated” then you cannot receive remote push notification events into your app. Instead when the push notification arrives on screen and is pressed your app is launched but without receiving a notification event.
Hello World for push notifications
To get started using the helper class, you will need your Android API Key for Firebase Cloud Messaging.
To subscribe to remote push notifications:
You will receive an Activated set to True if the notification is the likely result of a end-user actually pressing the notification.
To subscribe to device token changes:
Receiving remote push notifications in Delphi apps for Android and iOS is relatively straightforward with this helper class. In the end, all you need to know is the device token in order to send a message to a device.
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In the previous article we demonstrated how to roll your own Google Firebase Cloud Messaging and Apple APNS push notifications from Delphi apps in a unified manner. This article continues the conversation about how to easily receive and consume them in your Delphi mobile app.
Introduction
If you are authoring a Delphi service for the cloud, you may have the need to send and receive push notifications from your service to your mobile client application. You could use an existing BAAS provider to accomplish this, but why pay for this when you can roll your own so easily with Delphi?
Delphi provides a base set of classes in the units FMX.PushNotification.Android and FMX.PushNotification.iOS that do most of the heavy lifting and allow you to easily consume remote push notifications. In this conversation we will be demonstrating a helper class that unifies the approach for both platforms, uses TMessage callbacks for notifications and device token changes and adds some new missing features.
For more information about us, our support and services visit the Для просмотра ссылки Войди
The example contained here depends upon part of our Для просмотра ссылки Войди
Getting started on iOS
To receive push notifications on iOS you must:
- Already have created an Для просмотра ссылки Войди
или Зарегистрируйсяfor use in sending remote push notifications.
- Create an App ID on the Apple Developer website for your project.
- Enable Push Notifications for your App ID on the Apple Developer website for your project.
- A Provisioning Profile must exist on the Apple website that matches the identifier.
Getting started on Android
To receive push notifications on Android you must:
- Obtain a Firebase Cloud Messaging API Key by setting up cloud messaging on Для просмотра ссылки Войди
или Зарегистрируйся. This is also called the Server API Key under Firebase Cloud Messaging.
- Modify your AndroidManifest.xml to register an Intent and add the following receiver:
| 1 2 3 4 5 6 7 8 9 10 | <receiver android:name="com.embarcadero.gcm.notifications.GCMNotification" android:exported="true" android  ermission="com.google.android.c2dm.permission.SEND" ><intent-filter> <action android:name="com.google.android.c2dm.intent.RECEIVE" /> <category android:name="%package%" /> </intent-filter> </receiver> <service android:name="com.embarcadero.gcm.notifications.GCMIntentService" /> <%receivers%> |
For Android, we only need the Firebase Cloud Messaging API Key for our Delphi app.
TgoRemotePushReceiver class
The Для просмотра ссылки Войди
| 1 2 3 4 5 6 7 8 | TgoRemotePushReceiver = class(TObject) public constructor Create(const AGCMAppId: UnicodeString); destructor Destroy; override; public property DeviceToken: String read FDeviceToken; property Number: Integer read GetNumber write SetNumber; end; |
| 1 2 3 4 5 6 7 8 9 | TgoRemoteNotificationMessage = class(TMessage) public constructor Create(const ADataKey, AJson: String; const AActivated: Boolean); property DataKey: String read FDataKey; property Json: String read FJson; { Whether message is activated by the user (tapping in it) } property Activated: Boolean read FActivated; end; |
Since we are receiving a JSON payload for both Android and iOS we can examine the content here. This is useful is we want to include our own custom content in the payload that is app specific. See our Для просмотра ссылки Войди
If your device token changes on Android or iOS, the following TMessage is fired:
| 1 2 3 4 5 6 7 8 | { Device token change message } TgoDeviceTokenChangeMessage = class(TMessage) private FDeviceToken: String; public constructor Create(const ADeviceToken: String); property DeviceToken: String read FDeviceToken; end; |
The above message is fired initially when you device token is assigned after app startup. Due to the variances in the way device tokens are handled on iOS and Android this event could be immediate or delayed by the operating system.
As a developer you should also be prepared that the device token could change if your application is reinstalled, the operating system is updated as well as dynamically while your app is active.
Apple APNS quirks
On iOS Remote Push notification events are received only when your application is in the foreground or background. If your application is “force quit” also known as “terminated” then you cannot receive remote push notification events into your app. Instead when the push notification arrives on screen and is pressed your app is launched but without receiving a notification event.
iOS 8.x introduces a new approach called the PushKit which has the ability to silently launch your app into the background state. We will explore this in a future article.
Hello World for push notifications
To get started using the helper class, you will need your Android API Key for Firebase Cloud Messaging.
| 1 | RemotePushReceiver := TgrRemotePushReceiver.Create(MyAndroidApiKey); |
| 1 | TMessageManager.DefaultManager.SubscribeToMessage(TgoRemoteNotificationMessage, RemoteNotificationHandler); |
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 | procedure TMyClass.RemoteNotificationHandler(const Sender: TObject; const Msg: TMessage); var RemoteNotificationMessage: TgrRemoteNotificationMessage; Doc: TgoBsonDocument; begin Assert(Assigned(Msg)); Assert(Msg is TgoRemoteNotificationMessage); RemoteNotificationMessage := Msg as TgoRemoteNotificationMessage; { The user tapped this push notification, which resulted in the bringing the app to the foreground? } if (RemoteNotificationMessage.Activated) then Doc := TgrBsonDocument.Parse(RemoteNotificationMessage.Json); end; |
You will receive an Activated set to True if the notification is the likely result of a end-user actually pressing the notification.
To subscribe to device token changes:
| 1 | TMessageManager.DefaultManager.SubscribeToMessage(TgoDeviceTokenChangeMessage, DeviceTokenChangeListener); |
| 1 2 3 4 5 6 7 8 | procedure TMyClass.DeviceTokenChangeListener(const Sender: TObject; const M: TMessage); var DeviceTokenChangeMessage: TgoDeviceTokenChangeMessage; begin DeviceTokenChangeMessage := M as TgoDeviceTokenChangeMessage; Writeln('Device Token is ' + DeviceTokenChangeMessage.DeviceToken); end; |
Conclusion
Receiving remote push notifications in Delphi apps for Android and iOS is relatively straightforward with this helper class. In the end, all you need to know is the device token in order to send a message to a device.
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