Hi guys, :wave: I was wondering if it is possible ...

# android-architecture

[Novo Dimaporo]

Hi guys, 👋 I was wondering if it is possible to execute a room db transaction in the a usecase. Is it a good idea, I was thinking of creating a dao that looks like this

@Dao
interface EntityDao {
    @Transaction
    fun transaction(block: () -> Unit) {
        block()
    }
}

And expose this to the repository layer then the usecase.

[rattleshirt]

Or similar to https://github.com/chrisbanes/tivi/blob/main/data/db/src/commonMain/kotlin/app/tivi/data/db/DatabaseTransactionRunner.kt

[rattleshirt]

This is for SqlDelight but you could do something with Room as well https://github.com/chrisbanes/tivi/blob/main/data/db-sqldelight/src/commonMain/kotlin/app/tivi/data/SqlDelightTransactionRunner.kt

[rattleshirt]

https://github.com/chrisbanes/tivi/blob/v0.5.0/data-android/src/main/java/app/tivi/data/RoomTransactionRunner.kt

[rattleshirt]

For unit tests it would be easier to replace it

[Novo Dimaporo]

Thanks @rattleshirt, 👋 I ended up using the writeConnection block from RoomDatabase to execute transactions, and I realize it is a bad thing to make this accessible in the usecase since it is not flexible in changing datasource, we cant use transactions for remote datasource for example. I need to look into sqldelight and to the links you sent, I feel like everyone is using it sqldelight.

[rattleshirt]

Oh you don't have to use sqldelight per se. It is more about the concept of having a transaction runner injectable

[Novo Dimaporo]

I use this one,

suspend fun writeTransaction(block: suspend () -> Unit) {
        db.useWriterConnection { transactor ->
            transactor.immediateTransaction {
                block()
            }
        }
    }