IssueTracker

Project: platform/frameworks/support
Branch: androidx-master-dev

commit b90079595f33f58fece04026a97faa0d243acdb1
Author: Yuichi Araki <yaraki@google.com>
Date:   Wed Sep 18 16:55:49 2019

    Change the way to detect mismatch between POJO and query
   
    This fixes cursor mismatch warnings with expandProjection.
   
    Bug: 140759491
    Test: QueryMethodProcessorTest
    Change-Id: I7659002e5e0d1ef60fc1af2a625c0c36da0664d8

M       room/compiler/src/main/kotlin/androidx/room/processor/QueryMethodProcessor.kt
M       room/compiler/src/main/kotlin/androidx/room/solver/TypeAdapterStore.kt
M       room/compiler/src/main/kotlin/androidx/room/solver/query/result/PojoRowAdapter.kt
M       room/compiler/src/test/kotlin/androidx/room/processor/QueryMethodProcessorTest.kt
M       room/compiler/src/test/kotlin/androidx/room/testing/TestProcessor.kt

https://android-review.googlesource.com/1123258
https://goto.google.com/android-sha1/b90079595f33f58fece04026a97faa0d243acdb1

  The following changes were cherrypicked through Coastguard (https://android-build.googleplex.com/coastguard/)
  Release Track: (https://android-build.googleplex.com/coastguard/dashboard/6093116828680192/#/cherrypickHistory/all)
  Created: 2019-10-14 17:23:42.610596+00:00
  Changes: aosp/1123258
 

Project: platform/frameworks/support
Branch: androidx-master-dev

commit bdde5a1a970ddc9007b28de4aa29d60ffa588f08
Author: Yigit Boyar <yboyar@google.com>
Date:   Thu Apr 16 16:47:05 2020

    Re-factor how errors are dismissed when query is re-written
   
    This CL changes how we handle errors/warnings if query is
    re-written.
    There was a bug in expandProjection where we would report warnings
    for things that Room already fixes automatically (b/140759491).
    The solution to that problem (I7659002e5e0d1ef60fc1af2a625c0c36da0664d8)
    solved it by deferring validating of columns until after re-write
    decision is made. Unfortunately, this required changing PojoRowAdapter
    to have a dummy mapping until it is validating, make it hard to use
    as it does have a non-null mapping which is not useful.
   
    This CL partially reverts that change and instead rely on the log
    deferring logic we have in Context. This way, we don't need to break
    the stability of PojoRowAdapter while still having the ability to
    drop warnings that room fixes. This will also play nicer when we
    have different query re-writing options that can use more information
    about the query results.
   
    Bug: 153387066
    Bug: 140759491
    Test: existing tests pass
    Change-Id: I2ec967c763d33d7a3ff02c1a13c6953b460d1e5f

M       room/compiler/src/main/kotlin/androidx/room/log/RLog.kt
M       room/compiler/src/main/kotlin/androidx/room/processor/QueryMethodProcessor.kt
M       room/compiler/src/main/kotlin/androidx/room/solver/TypeAdapterStore.kt
M       room/compiler/src/main/kotlin/androidx/room/solver/query/result/PojoRowAdapter.kt

https://android-review.googlesource.com/1288456

For now we'll be just supporting one-off suspend functions in Room 2.1.0-alpha03. Coroutines stream functionality with channels is still a work in progress.

Relating to the original request, how about allowing a return type of Deferred<LiveData<T>> which suspends until LiveData<T>'s value has been set the first time?

I just tested out Room 2.1.0-alpha03 and added suspend to all of my functions.... there appears to be an issue with functions that use @Query() and UPDATE and DELETE queries.  Examples:

Code Example 1:
    @Query("DELETE FROM individual")
    suspend fun deleteAll()
Error:
    Deletion methods must either return void or return int (the number of deleted rows).

Code Example 2:
    @Query("UPDATE individual SET firstName = :firstName WHERE id = :id")
    suspend fun updateFirstName(id: Long, firstName: String)
Error:
    Not sure how to convert a Cursor to this method's return type (kotlin.Unit).

Async return types with @Query that perform UPDATE, DELETE or INSERT are not yet supported. This also applies to coroutines. We are actively working on adding this for the next alpha of 2.1.0. Subscribe to the bug for updates: https://issuetracker.google.com/issues/120227284

Hello.
Any updates on returning Channel<T> from DAO?
Will contributions be accepted for that feature?

Channels are experimental right now so we probably want to wait until it is stable.

Channels +1

Marking as fix since core coroutines are supported in 2.1, in the mean time we'll keep an eye on the Channels API to potentially support it once its upgraded out of experimental. https://issuetracker.google.com/issues/127328278

Is it expected that we still have to ensure that suspended functions aren't dispatched from the main thread?
The first call (eg `final SupportSQLiteStatement _stmt = __preparedStmtOfDeleteAll.acquire();`) is not wrapped in a callable and can't be done on the ui thread, so we still have to wrap suspensions with our own context.

Kotlinx.coroutines 1.2 released with cold stream abstraction Flow:
https://kotlin.github.io/kotlinx.coroutines/kotlinx-coroutines-core/kotlinx.coroutines.flow/-flow/index.html

It's in "preview" status, but maybe we also could expect some experimental version of Room with Flow support for observable requests