Checking the Subscription Status of a Topic

You might want to check if the current user is already subscribed to a topic. For example, your application may want to show a "SUBSCRIBE" button for users who have not yet subscribed to a topic and an "UNSUBSCRIBE" button instead for those users who are already subscribed to the topic.

Here is the sample code for checking the subscription status.

// Instantiate the target topic.
var topicName = "SendingAlert";
var topic = Kii.topicWithName(topicName);

// Check if the current user is subscribed to the topic.
var user = KiiUser.getCurrentUser();
user.pushSubscription().isSubscribed(topic).then(
  function(params) {
    var thePushSubscription = params[0];
    var theTopic = params[1];
    var isSubscribed = params[2];
    if(isSubscribed) {
      // The current user is subscribed to the topic.
    } else {
      // The current user is not subscribed to the topic.
    }
  }
).catch(
  function(error) {
    // Handle the error.
    var thePushSubscription = error.target;
    var errorString = error.message;
  }
);

// Instantiate the target topic.
var topicName = "SendingAlert";
var topic = Kii.topicWithName(topicName);

// Check if the current user is subscribed to the topic.
var user = KiiUser.getCurrentUser();
user.pushSubscription().isSubscribed(topic, {
  success: function(thePushSubscription, theBucket, isSubscribed) {
    if(isSubscribed) {
      // The current user is subscribed to the topic.
    } else {
      // The current user is not subscribed to the topic.
    }
  },
  failure: function(theTopic, errorString) {
    // Handle the error.
  }
});

Here's a description of the sample code:

Instantiates a topic.
Creates a KiiPushSubscription instance by calling the pushSubscription method.
Calls the isSubscribed method to check if the current user is already subscribed to the topic.