Subscribing to a Topic

Subscription to a topic is necessary to receive Push to User notifications. Once a user subscribes to a topic, all push messages sent to this topic will be delivered to the user.

The following sample code subscribes to an application-scope topic named SendingAlert.

try {
  // Instantiate an existing topic in the application scope.
  String topicName = "SendingAlert";
  KiiTopic topic = Kii.topic(topicName);

  // Subscribe to the topic.
  KiiUser user = KiiUser.getCurrentUser();
  KiiPushSubscription sub = user.pushSubscription();
  sub.subscribe(topic);
} catch (IOException ioe) {
  // Handle the the error.
} catch (AppException e) {
  // Handle the the error.
}

// Instantiate an existing topic in the application scope.
String topicName = "SendingAlert";
KiiTopic topic = Kii.topic(topicName);

// Subscribe to the topic.
KiiUser user = KiiUser.getCurrentUser();
KiiPushSubscription sub = user.pushSubscription();
sub.subscribe(topic, new KiiPushCallBack() {
  @Override
  public void onSubscribeCompleted(int taskId, KiiSubscribable target, Exception exception) {
    if (exception != null) {
      // Handle the error.
      return;
    }
  }
});

The next sample code subscribes to a group-scope topic named GroupTopic. In this sample code, we are getting the existing topic with its URL.

try {
  // Instantiate an existing group.
  KiiGroup group = KiiGroup.createByUri(groupUri);

  // Instantiate an existing topic in the group scope.
  String topicName = "GroupTopic";
  KiiTopic topic = group.topic(topicName);

  // Subscribe to the topic.
  // (The current user must be a group member)
  KiiUser user = KiiUser.getCurrentUser();
  KiiPushSubscription sub = user.pushSubscription();
  sub.subscribe(topic);
} catch (IOException ioe) {
  // Handle the the error.
} catch (AppException e) {
  // Handle the the error.
}

// Instantiate an existing group.
KiiGroup group = KiiGroup.createByUri(groupUri);

// Instantiate an existing topic in the group scope.
String topicName = "GroupTopic";
KiiTopic topic = group.topic(topicName);

// Subscribe to the topic.
// (The current user must be a group member)
KiiUser user = KiiUser.getCurrentUser();
KiiPushSubscription sub = user.pushSubscription();
sub.subscribe(topic, new KiiPushCallBack() {
  @Override
  public void onSubscribeCompleted(int taskId, KiiSubscribable target, Exception exception) {
    if (exception != null) {
      // Handle the error.
      return;
    }
  }
});

The last sample code subscribes to a user-scope topic named MyTODO.

try {
  // Instantiate an existing topic in the user scope.
  String topicName = "MyTODO";
  KiiTopic topic = KiiUser.topic(topicName);

  // Subscribe to the topic.
  KiiUser user = KiiUser.getCurrentUser();
  KiiPushSubscription sub = user.pushSubscription();
  sub.subscribe(topic);
} catch (IOException ioe ) {
  // Handle the error.
} catch (AppException e) {
  // Handle the error.
}

// Instantiate an existing topic in the user scope.
String topicName = "MyTODO";
KiiTopic topic = KiiUser.topic(topicName);

// Subscribe to the topic.
KiiUser user = KiiUser.getCurrentUser();
KiiPushSubscription sub = user.pushSubscription();
sub.subscribe(topic, new KiiPushCallBack() {
  @Override
  public void onSubscribeCompleted(int taskId, KiiSubscribable target, Exception exception) {
    if (exception != null) {
      // Handle the error.
      return;
    }
  }
});

For all examples, here is a brief description of the sample code:

Instantiates a target topic.
Creates a KiiPushSubscription instance by calling the pushSubscription method.
Calls the subscribe method passing the target topic.