Checking if a Topic Exists

You can check if a certain topic already exists from your mobile application.

The following example checks if the specified topic already exist in an application scope (you can similarly check the topic existence in a user and group scopes).

  • // Instantiate the target topic.
    var topic = Kii.topicWithName("SendingAlert");
    
    // Check if the topic exists.
    topic.exists({
      success: function(existed) {
        if (existed) {
          // The topic already exists.
        } else {
          // The topic does not exist.
        }
      },
      failure: function(errorString) {
        // Handle the error.
      }
    });
  • // Instantiate the target topic.
    var topic = Kii.topicWithName("SendingAlert");
    
    // Check if the topic exists.
    topic.exists().then(
      function(existed) {
        if (existed) {
          // The topic already exists.
        } else {
          // The topic does not exist.
        }
      }
    ).catch(
      function(error) {
        // Handle the error.
        var theTopic = error.target;
        var errorString = error.message;
      }
    );

This is the brief explanation of the sample code:

  • Get an instance of the topic that you want to check if it exists.
  • Execute the exists method to check if the topic exists or not.