Firestore Tutorial Part 13 – DOCUMENT CHANGES – Android Studio Tutorial



In part 13 of the Firestore tutorial we will learn how to use DocumentChanges to listen to granular changes in our data set. This way we can retrieve only particular documents that have been added, modified or removed, rather than always retrieving all documents of a query at once. This is particularly useful if we want to display our data in a RecyclerView.
We get a List of DocumentChange objects by calling getDocumentChanges on the QuerySnapshot that we get passed in the onEvent method of a SnapshotListener.
DocumentChanges can have 3 types: ADDED, MODIFIED and REMOVED, depending on which kind of change happened to the document.
From these DocumentChange objects we can retrive the affected DocumentSnapshot by calling getDocument on it. With getOldIndex and getNewIndex we can get the position of the document before and after the change.

Watch the whole playlist:

Code for this part:
https://gist.github.com/codinginflow/10909b8c8430c57020797ca5c8b3a112

____________________
💻 Find the BEST programming tutorials on TutHub:
https://tuthub.io

⭐ Get my MVVM Caching Course now:
https://codinginflow.com/caching

❗ Subscribe to the channel:
https://www.youtube.com/c/codinginflo…

📨 Subscribe to the Coding in Flow newsletter:
https://codinginflow.com/newsletter

❓ Join our free developer community:
https://discord.gg/TSnMvmc

📣 Follow Coding in Flow on other sites:
Facebook: https://www.facebook.com/codinginflow
Instagram: https://www.instagram.com/codinginflow
TikTok: https://www.tiktok.com/@codinginflow
Twitter: https://twitter.com/codinginflow
Github: https://github.com/codinginflow

💰 Business requests, sponsoring, etc.: info@codinginflow.com

Views :16476
android studio

Source by Coding in Flow

Mourad ELGORMA

Fondateur de summarynetworks, passionné des nouvelles technologies et des métiers de Réseautique , Master en réseaux et système de télécommunications. ,j’ai affaire à Pascal, Delphi, Java, MATLAB, php …Connaissance du protocole TCP / IP, des applications Ethernet, des WLAN …Planification, installation et dépannage de problèmes de réseau informatique……Installez, configurez et dépannez les périphériques Cisco IOS. Surveillez les performances du réseau et isolez les défaillances du réseau. VLANs, protocoles de routage (RIPv2, EIGRP, OSPF.)…..Manipuler des systèmes embarqués (matériel et logiciel ex: Beaglebone Black)…Linux (Ubuntu, kali, serveur Mandriva Fedora, …). Microsoft (Windows, Windows Server 2003). ……Paquet tracer, GNS3, VMware Workstation, Virtual Box, Filezilla (client / serveur), EasyPhp, serveur Wamp,Le système de gestion WORDPRESS………Installation des caméras de surveillance ( technologie hikvision DVR………..). ,

Laisser un commentaire

Votre adresse e-mail ne sera pas publiée. Les champs obligatoires sont indiqués avec *