Coroutines MVVM - mayurparmar2/AlarmDemo GitHub Wiki

import android.content.Context
import androidx.room.Database
import androidx.room.Room
import androidx.room.RoomDatabase

@Database(entities = [User::class], version = 1)
abstract class AppDatabase : RoomDatabase() {
    abstract fun userDao(): UserDao

    companion object {
        @Volatile
        private var INSTANCE: AppDatabase? = null

        fun getInstance(context: Context): AppDatabase {
            return INSTANCE ?: synchronized(this) {
                val instance = Room.databaseBuilder(
                    context.applicationContext,
                    AppDatabase::class.java,
                    "app_database"
                ).build()
                INSTANCE = instance
                instance
            }
        }
    }
}

class UserRepository(private val userDao: UserDao) {
    val allUsers: LiveData<List<User>> = userDao.getAllUsers()

    suspend fun insert(user: User) = userDao.insert(user)
    suspend fun update(user: User) = userDao.update(user)
    suspend fun delete(user: User) = userDao.delete(user)
}

import androidx.lifecycle.LiveData
import androidx.lifecycle.ViewModel
import androidx.lifecycle.viewModelScope
import kotlinx.coroutines.launch

class UserViewModel(private val repository: UserRepository) : ViewModel() {
    val allUsers: LiveData<List<User>> = repository.allUsers

    fun insert(user: User) {
        viewModelScope.launch {
            repository.insert(user)
        }
    }

    fun update(user: User) {
        viewModelScope.launch {
            repository.update(user)
        }
    }

    fun delete(user: User) {
        viewModelScope.launch {
            repository.delete(user)
        }
    }
}