Question on ktor + exposed + coroutines

# coroutines

[waltermcq]

Question on ktor + exposed + coroutines

[waltermcq]

I'm trying to insert a new user into my database using the exposed DSL, with transactions that are wrapped with coroutines e.g. the dqQuery {} method frequently found for this purpose

[waltermcq]

Here's basically what the insert function is:

override suspend fun newUser(id: String, name: String): UserAgg {
        return dbQuery {
            val userRow = UserTable.insert {
                it[this.id] = id
                it[this.name] = name
            }.resultedValues!!.first()

          getUserById(UserId(userRow[UserTable.id]))!!
        }
    }

[waltermcq]

Heres's dbQuery()

suspend fun <T> dbQuery(
    block: () -> T): T =
    withContext(<http://Dispatchers.IO|Dispatchers.IO>) {
        transaction { block() }
    }

[waltermcq]

The issue is in the newUser function, when I call getUserById to get the new id (specifically, a uuid) from the database after the insert, intellij tells me that getUserById must be called within a coroutine body

I can't wrap getUserById in a dbQuery() call inside newUser, I get the same issue (as its apparently not a coroutine body) (edited) 

what is the best way to call getUserById() given the need for a coroutine body?

[louiscad]

The block lambda of the dbQuery function is not suspending, that's why.

[waltermcq]

@louiscad okay, what would be the proper way to make the block lambda suspending?

[waltermcq]

I am quite new to both kotlin and working with coroutines, thanks for your patience

[louiscad]

@waltermcq Adding suspend as a prefix in the type of block, if transaction takes a suspending lambda. Otherwise, you'll need to slip your code to do it in two steps so there's no suspend call in the transaction.

[waltermcq]

okay, I did add the suspend to the type of block, but then the block() call itself requires a coroutine body

[waltermcq]

I think I am a bit over my head here, so I'm going to go do some reading

[waltermcq]

anyway, thanks for your help @louiscad