{"id":70467,"date":"2025-03-19T16:16:12","date_gmt":"2025-03-19T10:46:12","guid":{"rendered":"https:\/\/www.tothenew.com\/blog\/?p=70467"},"modified":"2025-03-19T16:35:00","modified_gmt":"2025-03-19T11:05:00","slug":"live-activities-introduction-and-setup-part-2","status":"publish","type":"post","link":"https:\/\/www.tothenew.com\/blog\/live-activities-introduction-and-setup-part-2\/","title":{"rendered":"Live Activities Introduction and Setup \u2013 Part 2"},"content":{"rendered":"

Introduction<\/h2>\n

In Part 1<\/a> we learned about how to set up live activities from scratch. We learned about how to set up, design, and implement live activities for different modes of the iPhone including Lock Screen and Dynamic Island. We learned about the life cycle of activity from the app. How to start, update, and end an activity from the app only. But the real power of live activities comes when it works with a backend push notification when the app is in a killed state. To update users about new actions on that activity through push notifications show the real use of this api. In this part, we will learn about the live activity life cycle through push notifications.<\/p>\n

Push Notifications for lifecycle operations<\/h2>\n

Start Activity<\/h3>\n

On devices with iOS 17.2 or newer, it\u2019s possible to obtain the push token without starting the live activity. To do so, we need to observe the pushToStartTokenUpdates<\/strong> asynchronous sequence. Once we receive it and send it to the backend, it\u2019s possible to start the live activity anytime using push notification.<\/p>\n

\"Startin

Startin a activity<\/p><\/div>\n

Update Activity<\/h3>\n

We need to send the special push token to our backend to receive live activity updates. After starting the live activity receiving this push token is feasible. The activity instance has an asynchronous sequence pushTokenUpdates<\/strong>, which emits the push token every time it is updated.<\/p>\n

\"Update

Update Token<\/p><\/div>\n

Once we receive the new push token, we should send it to our backend. It\u2019s important to note that this push token can change during the live activity\u2019s lifecycle, so we need to keep observing the push token updates and send it every time it changes.<\/p>\n

End Activity<\/h3>\n

Once our event ends we can easily end that particular live activity by sending an end push notification on the same update token.<\/p>\n

Push notification payloads<\/h3>\n

It is important to understand how the whole system works. That\u2019s why we will talk about what should be sent in the request payload to the Apple Push Notification service (APN).<\/p>\n

Below, you can see the payload needed to start a live activity (for iOS 17.2).<\/p>\n