jaanesen / background-app

Simple application for testing the observer query's background functionality. The work was done as part of my master thesis.

Background-App

Simple application for testing the observer query's background functionality. The work was done as part of my master thesis.

Flow

The application's main flow is the column on the right, which describes the events leading to a notification being dispatched. The left side concerns the actual application on the phone with setup, including authorizing User Notification- and HealthKit frameworks and the application instantiating the background observer query. henever a new resting heart rate value is stored or the existing value is updated, the HealthKit framework will trigger the observer query's update handler. The update handler will then call for a statistics collection query that updates the app's existing variables. If the resting heart rate is, in fact, changed, it will schedule a notification in the notification center. The notification is then supposed to be dispatched, and it is possible to verify if the background functionality is working or not.

Class diagram

This application has the same user interface as the Resting Heart Rate App and has some identical elements in the class diagram.

• [V-1,2,3,4,5] the same as in the Resting Heart Rate App.
• [F-1] Start function. Initializes the application by calling F-4 to authorize the required HealthKit permissions, and F-5 to authorize the use of User Notifications. When the required permissions are obtained, the function starts the observer query by calling F-2.
• [F-2] Start observer query function. This function initializes an observer query with a completion handler which calls the F-3 function to fetch the observed change in resting heart rate.
• [F-3] Run heart rate query function. Checks the fetched HR and calls F-6 with the required parameters to dispatch a notification.
• [F-4] Handles permission to read/write health-related data, specifically in this example: resting heart rate.
• [F-5] Handles permission to display notifications.
• [F-6] Notification dispatching function. With two additional parameters: title: String, body: String.
• [A-1] Red line illustrates F-1 calling F-4 and F-5.
• [A-2] Green line illustrates F-2 calling F-3 every time the observer query is triggered.