I have no code but only a special question regarding Cloud Firestorage by Google.
Im using currently a listener for my Firestorage within my react-native-app which I also use expo for.
I know that as long as I stay in the app and tab out of the window, all data downloaded by the listener is getting stored in a temporary cache so when I come back to the screen with the listener, the listener doesnt need to download all data again but rather the missing sample.
My question would be: Does this also apply if I close the app entirely, for example for multiple days so that my token for authentification expires and I need to log myself in again into the app or rather into my Firebase?
(I want to prevent downloading all data the listener points to only because I restarted the app.)
As explained here the firestore persistance for the web is disk persistance so it survies App and devices restarts. Multiple days should also be fine.
I have a Web App tha is using firestore and very heavily offline capabilities. We never had issues with that.
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This is not a problematic question, it was asked because just wanted to know what's actually going on behind it, I can't find an answer in any documentation.
When i open the app without internet it shows the data from firebase, i try to restart then it also shows, i try to clear the cache but it shows the data like it shows from the local database, Why is this happening, is there a built-in local storage or something in Firebase Flutter?
Firestore SDKs cache any data that they've recently seen, as well as any pending writes from the local client that haven't been synchronized to the server yet. On mobile clients (iOS and Android) this cache is enabled by default, while on web you can enable it with an API call.
For more on this, see the Firebase documentation on accessing Firestore data while you're offline.
I came across a wonderful feature of Firebase offline feature. I integrated that in my app just by writing one line of code in my main.dart file after initializing Firebase await FirebaseDatabase.instance.setPersistenceEnabled(true);
Question 1 :
I couldn't able to understand the database.keepSynced(true) function because without using this line of code, my app is persisting old as well as fetching new updated data, so what this exactly does ?
Question 2 :
How could I prevent the write operations when a user is offline, because I read that after setting persistence enabled, it makes a queues of write operations and update them when user gets online, so how could I stop this ?
Question 3 :
Is this persistence feature going to work in IOS device as well or need some permission settings first ?
Thanks
When you call FirebaseDatabase.instance.setPersistenceEnabled(true) you're allowing Firebase to create a local file on the device where it persists any data it's recently read, and all writes that are pending while the device is offline.
When you call keepSynced(true) on a node, you are telling the SDK to always keep that node synchronized. It essentially creates a onValue listener on the node without any handler code, so you're purely doing this to keep the data synchronized for when the device does go offline.
By combining keepSynced(true) with setPersistenceEnabled(true), you're specifying that you want the app to continue working when it's offline across restarts, and which data is needed for that.
If you call keepSynced(true) on the root of your database, you're telling the SDK to synchronize all data in the database to the disk cache. While this may initially be a quick way to get offline mode for your app working, it typically won't scale when you more people start using your app.
If you only want to allow write operations while the client has a connection to the database backend, you can register a local listener to the .info/connected node, which is a true value when there is a connection and false otherwise.
Note that Firebase doesn't require this, as it queues the pending writes and executes them when the connection is restored. In general, I'd recommend working with the system here instead of against it, and also trying to make your app work gracefully in the offline scenario. In many cases there is no need to disable functionality while the app is offline.
Offline disk persistence is available on Android and iOS, but not on web.
I am building a flutter app with cloud firestore and I am using the offline capabilities.
When coming back online after I made changes offline, it seems like the changes take quite some time to synchronise (sometime up to a minute).
Is there any ways to force the synchronisation manually so that I can could trigger it myself when listening for the device to get back online?
Thanks a lot for your help!
The native SDKs for iOS, Android, and Web have API calls that allow you to explicitly manage connection state. While those are not explicitly made for your use-case, it'd be worth a try to see if disabling/re-enabling the network in short succession makes a difference.
Unfortunately those methods are currently not wrapped in the Firestore class of the FlutterFire library.
There is an open issue in the Github repo to track demand and progress on it. I just gave it an upvote.
If I have a Firestore database that I want to constantly be updating (and listeners in my code to constantly be responding to backend updates), should the code that's responsible for updating the database belong in the android app that will be available for download to other people? Or is it supposed to be somewhere else?
For example, the code for creating a document with user info within the collection "Users" belongs in every instance of the app that I publish, because I want every user using my app to be able to write their login info to the Firestore database after they register through Firebase Auth.
But if I have a different collection of data that I want to be available to all users using my app, and I want to be updating that data constantly, should I be updating it with code that goes in with my production level app, or should that be happening somewhere else? And if it should be happening somewhere else, where should that be/how should that be done?
I'd appreciate any help with this!
Never mind, I found the answer to my own question. Firebase provides users with Cloud Functions, which can run on the server-side to respond to new data events.
You might also be interested in Realtime Database, it will mean you don't have to write any of these listeners to the data and it does it all automatically. Check it out here;
https://firebase.google.com/docs/database/rtdb-vs-firestore
I'm thinking moving an Android app's persistent data to Firebase Database. Currently I use Sqlite with a Python HTTP REST service.
In the app, I have a big list of cities, called citiesList. Since the list is quite big and hardly updated, I don't want the app fetch the list whenever it goes online.
My current strategy is provide a citiesListVersion. When the app goes online, it checks citiesListVersion. If the server's citiesListVersion is newer, the app will fetch citiesList from server. Otherwise, the app continues working with the cached data.
My question is: can I keep my current strategy when moving to Firebase Database? As I understand, Firebase tries to sync data whenever the app goes online.