Chat Done Right
- 1. Chat Done Right! With Android & Firebase
- 2. How is this going to work? This is NOT a lecture… ‣ Interactive discussion ‣ There is no “questions” slide
- 3. Our Tools Android Kotlin Firebase Realtime Database Cloud Functions Database Rules
- 4. What we’re building A chat app (surprise) that needs: 1. Authentication 2. Users 3. To send messages 4. To show active chats 5. A contact list 6. Send notifications 7. Group management
- 6. Our Tools Android Kotlin Firebase Realtime Database Cloud Functions Database Rules
- 7. Write directly to DB from Android ๏ CRUD - You can do just about anything from the client ๏ Persistence and caching to writes to DB ๏ Super super fast ๏ But the are somethings better done with a Cloud Function
- 8. Database Rules Insecure rules (public access) Default rules (read/write if authorised)
- 10. All Chat Previews user_uid_1 user_uid_2 chat_id_1 chat_id_2
- 11. All Chat Previews user_uid_1 user_uid_2 chat_id_1 chat_id_2 But how do we know which chat previews to update when a message is sent?
- 14. But wait, there is! ๏ Unnecessary logic on client apps ๏ Direct write access to DB ๏ Security rules management easily becomes a nightmare
- 15. Introducing Cloud Functions ๏ Conditional triggering & throttling ‣ On node changes (has auth object) ‣ Client SDK callable (has auth object) ‣ HTTP Request ๏ Central & Secure ๏ Node.js ๏ Logging ๏ Admin rights on all operations
- 17. Calling a function Cloud FunctionAndroid App https://tinyurl.com/chitchatCloud https://tinyurl.com/chitchatAndroid
- 19. Chat Done Right: Using Cloud Functions Trigger onWriteSend message payload onSendMessage Function Realtime DatabaseAndroid App User 1
- 20. Why the direct write ๏ Caches the write (local state management) ๏ Avoid response delay But! ๏ Write access risks Solution Only allow message creates (not updates) for chats that an authorised user is part of.
- 21. Remember these Insecure rules (public access) Default rules (read/write if authorised)
- 22. Database Rules Adding security: Taking it up a notch
- 23. Trigger onWriteSend message payload onSendMessage Function Realtime DatabaseAndroid App User 1
- 24. Using Cloud Functions for Chat onSendMessage Function Chat Members Node Fetch Chat Member IDs Write to each Chat Preview Chat Preview Node
- 25. Using Cloud Functions for Chat Android Apps User 1 User 2 User 3 All user Chat previews Updated Chat Preview Node Notifications sent
- 26. Take Homes •Cloud functions takes logic off the client • This avoids repetition between the platforms • Easier to think about security • If you can use a Cloud Function do it •Writing directly to DB from client • Firebase handles the persistence • Caches writes & reads wisani@nona.digital adrian@nona.digital https://tinyurl.com/chitchatCloud https://tinyurl.com/chitchatAndroid