``` @Database(entities = [Something::class], version = 1, exportSchema = false) abstract class MyDat...

# kodein

[Joan Colmenero]

@Database(entities = [Something::class], version = 1, exportSchema = false)
abstract class MyDatabase : RoomDatabase() {

    abstract fun myDao(): MyDao

    companion object {

        @Volatile
        private var INSTANCE: MyDatabase? = null

        fun getInstance(context: Context): MyDatabase =
            INSTANCE ?: synchronized(this) {
                INSTANCE ?: buildDatabase(context).also { INSTANCE = it }
            }

        private fun buildDatabase(context: Context) =
            Room.databaseBuilder(
                context.applicationContext,
                MyDatabase::class.java, "sample_db"
            )
                .allowMainThreadQueries()
                .build()
    }

}

[salomonbrys]

Can you be more specific about what you are trying to achieve ?

[streetsofboston]

First, is is MyDatabase or BrewDatabase? Let's assume it is BrewDatabase.

Remove the companion object stuff.
Then have a module with a binding, or just a binding, that is something like this

bind<BrewDatabase>() with singleton { Room.databaseBuilder(instance(), BrewDatabase::class.java, "sample_db").allowMainThreadQueries().build() }

[streetsofboston]

All the rest is annotation driven and kodein, or any other DI/SL, cannot help here

[Joan Colmenero]

I want to DI this MyDatabase object, like I'm doing with all my Presenter, Activity, etc... but now I never did it before, so I want to call for instance this MyDao from everywhere on my APP, because now I'm doing MyDatabase.myDao.anyMethod() and I want to achieve something like I'm doing with my Repository or Usecase that I have a service as a parameter and I can use them, so I don't know the way to move this into DI so I can use it from any other class instead of doing always MyDatabase.getInstance(this).myDao.someMethod

[Joan Colmenero]

Is it clear?

[Joan Colmenero]

@streetsofboston don't get what you are trying to say with

All the rest is annotation driven and kodein, or any other DI/SL, cannot help here

[streetsofboston]

The annotation creates source code, a class that is a subclass of MyDatabase (or BrewDatabase?).
The call to Room.databaseBuilder...... will return you an instance of that subclass.

[Joan Colmenero]

Yes, my question is, can I avoid using MyDatabase.getInstance(this).myDao().insertUser(someUser) eveytime? I mean avoid this : MyDatabase.getInstance(this).myDao()

[streetsofboston]

The you can do val myDb: MyDatabase by kodein.instance() just like any other kodein dependency

[streetsofboston]

Also, is it MyDatabase or BrewDatabase?

[streetsofboston]

Ah... You corrected it, it's MyDatabase 😀

[streetsofboston]

And then you can use myDb.myDao() etc

[Joan Colmenero]

So I don't have to create a module for this

[Joan Colmenero]

As I'm doing with the rest of my stuff?

[streetsofboston]

You could. It depends. Modules are just for your own organization of the code.

[Joan Colmenero]

Ahhh, Yes, sorry so I can create a module called databaseModule and inside put something like
bind<MyDatabase>() with singleton {
Room.databaseBuilder(
context.applicationContext,
MyDatabase::class.java, "sample_db"
)
.allowMainThreadQueries()
.build()
}

[Joan Colmenero]

Is that correct?

[Joan Colmenero]

So, I have to remove all of the companionObject thing? right?

[streetsofboston]

Yup, exactly.

You can even make the context.applicationContext a dependency (from another module) on which this dependency depends. 😀

[streetsofboston]

Yup, either use the kodein stuff or use the companion object construct.

[Joan Colmenero]

Oh, true, I need the context

[Joan Colmenero]

But how do I create a Bind for the context?

[Joan Colmenero]

Should be something like this : https://github.com/Kodein-Framework/Kodein-DI/issues/32#issuecomment-242915281, but I'm not getting app as a parameter I have this

val contextModule = Kodein.Module("contextModule") {

    bind<Context>() with instance()

}

[streetsofboston]

That looks recursive, the above code snippet.

bind<MyApplication> with singleton { MyApplication.INSTANCE }

And MyApplication is your Application subclass, which is a Context subclass as well. Be sure to get the dependency (in your Database Module) using instance<MyApplication>() though.

[Joan Colmenero]

@salomonbrys You know about it? How can I bind the context? So I can use to create the Room.databaseBuilder(context.applicationContext...) ?

[romainbsl]

You could also use a factory, and passing the context to retrieve the right instance, like:

[romainbsl]

// Binding
bind<Database>() with factory { ctx -> Room.databaseBuilder(ctx) }
// Retrieving
val db: Database by kodein.instance(arg = context)