Feature Request: Singleton management [173726702]

Fixed

Feature Request

Status Update

No update yet.

Description

ru...@gmail.com

created issue #1

Nov 21, 2020 05:17AM

DataStore Component used: All
DataStore Version used: 1.0.0-alpha-04

DataStoreFactory and PreferenceDataStoreFactory include the following warning:

The user is responsible for ensuring that there is never more than one instance of SingleProcessDataStore acting on a file at a time.

Could the factories be made responsible for returning the same instance if they've already created one, so the consuming app doesn't need to manage that themselves?

Comments

ap...@google.com <ap...@google.com> #2Feb 17, 2021 01:23AM

Hi - thanks for raising this, I'll dig into our SwipeDismissableNavHost and try to find out why we didn't support the back button already. Will report back on this thread.

ro...@google.com <ro...@google.com> Feb 17, 2021 09:18PM

Marked as fixed.

ap...@google.com <ap...@google.com> #3Feb 23, 2021 05:22PM

An early draft of SwipeDismissableNavHost did implement back button support, but it was thought not to be required - we will submit a change to add the support back again.

ru...@gmail.com <ru...@gmail.com> #4Feb 25, 2021 01:46AM

Project: platform/frameworks/support
Branch: androidx-main

commit 78d498661680a95d2705d5e6dbb1c0438c50fa30
Author: stevebower <stevebower@google.com>
Date: Tue Dec 14 13:42:48 2021

Support back button in SwipeDismissableNavHost.

Added back button handling for navigation to
SwipeDismissableNavHost, using the implementation
from Compose Material NavHost. This enables use
of the emulator's back button for local testing,
as well as in any devices that support a hardware back button.

Test: Run tests for wear.compose.navigation.

Bug: 210205624

Relnote: "We have added a back button handler to
SwipeDismissableNavHost, so that pressing
back navigates to the previous level
in the navigation hierarchy."
Change-Id: I5b08689b1651c1aae5f038f058956007df398909

M wear/compose/compose-navigation/build.gradle
M wear/compose/compose-navigation/src/androidTest/kotlin/androidx/wear/compose/navigation/SwipeDismissableNavHostTest.kt
M wear/compose/compose-navigation/src/main/java/androidx/wear/compose/navigation/SwipeDismissableNavHost.kt

https://android-review.googlesource.com/1922537

ro...@google.com <ro...@google.com> #5Feb 25, 2021 06:17AM

A few things led to the approach that we ended up with:

Since we need the result of context.filesDir, and context.filesDir can do file IO, we need to accept a callback for generating the file. Deduping on just the relative path (String) is easier than deduping on the callback () -> File.
You can't really depend on context at the top level of a kotlin file or in a static/companion object.
We wanted something that people could easily copy&paste into their code and get going without having to worry to much about it.
(Unrelated to your question but..) Different calls to createDataStore for the same file names could have different construction params. The various params probably don't implement value equality so you can't really throw errors in these cases (we'd probably just have to take the first set of params then silently ignore future ones).

That said, if you can just inject the DataStore using hilt with @Singleton you don't have to worry about any of this.

jd...@xooloo.com <jd...@xooloo.com> #6Feb 25, 2021 10:23AM

Release notes for that features are broken.

Not only they suggest to use = instead of by (which make the code snippet invalid), but they forget to mention how we are supposed to deal with the new Serializer argument.

jd...@xooloo.com <jd...@xooloo.com> #7Feb 25, 2021 10:38AM

How are we suppose to migrate code like this:

private val _store = context.createDataStore("store", migrations = listOf(
            SharedPreferencesMigration(context, "store")
    ))

There is not way to create SharedPreferencesMigration without context reference.

private val Context.store by preferencesDataStore("store", migrations = listOf(
            SharedPreferencesMigration(context, "store") // error context do not exists
    ))

ro...@google.com <ro...@google.com> #8Feb 26, 2021 04:08PM

Status: In Progress (Accepted) (reopened)

Thanks for reporting - we are working on a fix for the migrations for next release.

ap...@google.com <ap...@google.com> #9Feb 26, 2021 07:24PM

Project: platform/frameworks/support
Branch: androidx-main

commit b64da89bd9caa4492b296a701e08d3d6fb7f2e52
Author: rohitsat13 <rohitsat@google.com>
Date: Fri Feb 26 09:51:28 2021

Change migrations param to migrationProducers param for datastore property delegate since you may need context to create a sp migration for example.

Test: See new tests
Relnote: You can now add a migration that depends on context to your `dataStore` and `preferencesDataStore` property delegate.
Bug: 173726702
Change-Id: I4ef69b0eed544cde4f05cdee9e885d36af0f4abb

M datastore/datastore-preferences-rxjava2/api/current.txt
M datastore/datastore-preferences-rxjava2/api/public_plus_experimental_current.txt
M datastore/datastore-preferences-rxjava2/api/restricted_current.txt
M datastore/datastore-preferences-rxjava2/src/androidTest/java/androidx/datastore/preferences/rxjava2/RxPreferenceDataStoreDelegateTest.kt
M datastore/datastore-preferences-rxjava2/src/main/java/androidx/datastore/preferences/rxjava2/RxPreferenceDataStoreDelegate.kt
M datastore/datastore-preferences-rxjava3/api/current.txt
M datastore/datastore-preferences-rxjava3/api/public_plus_experimental_current.txt
M datastore/datastore-preferences-rxjava3/api/restricted_current.txt
M datastore/datastore-preferences-rxjava3/src/androidTest/java/androidx/datastore/preferences/rxjava3/RxPreferenceDataStoreDelegateTest.kt
M datastore/datastore-preferences-rxjava3/src/main/java/androidx/datastore/preferences/rxjava3/RxPreferenceDataStoreDelegate.kt
M datastore/datastore-preferences/api/current.txt
M datastore/datastore-preferences/api/public_plus_experimental_current.txt
M datastore/datastore-preferences/api/restricted_current.txt
M datastore/datastore-preferences/src/androidTest/java/androidx/datastore/preferences/PreferenceDataStoreDelegateTest.kt
M datastore/datastore-preferences/src/androidTest/java/androidx/datastore/preferences/SharedPreferencesToPreferencesTest.kt
M datastore/datastore-preferences/src/main/java/androidx/datastore/preferences/PreferenceDataStoreDelegate.kt
M datastore/datastore-rxjava2/api/current.txt
M datastore/datastore-rxjava2/api/public_plus_experimental_current.txt
M datastore/datastore-rxjava2/api/restricted_current.txt
M datastore/datastore-rxjava2/src/androidTest/java/androidx/datastore/rxjava2/RxDataStoreDelegateTest.kt
M datastore/datastore-rxjava2/src/main/java/androidx/datastore/rxjava2/RxDataStoreDelegate.kt
M datastore/datastore-rxjava3/api/current.txt
M datastore/datastore-rxjava3/api/public_plus_experimental_current.txt
M datastore/datastore-rxjava3/api/restricted_current.txt
M datastore/datastore-rxjava3/src/androidTest/java/androidx/datastore/rxjava3/RxDataStoreDelegateTest.kt
M datastore/datastore-rxjava3/src/main/java/androidx/datastore/rxjava3/RxDataStoreDelegate.kt
M datastore/datastore/api/current.txt
M datastore/datastore/api/public_plus_experimental_current.txt
M datastore/datastore/api/restricted_current.txt
M datastore/datastore/src/androidTest/java/androidx/datastore/DataStoreDelegateTest.kt
M datastore/datastore/src/androidTest/java/androidx/datastore/migrations/SharedPreferencesMigrationTest.kt
M datastore/datastore/src/main/java/androidx/datastore/DataStoreDelegate.kt

https://android-review.googlesource.com/1606566

ro...@google.com <ro...@google.com> Mar 5, 2021 07:19PM