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Local Storage

KAppMaker supports Local Storage using Room for offline data storage and retrieval.

Database Configuration​

The AppDatabase is pre-configured for both platforms and located in data/source/local. The database name is defined as: (located in Constants):

const val LOCAL_DB_STORAGE_NAME = "local_storage.db"

Creating an Entity and DAO​

Create Your Entity​

Entities represent tables within the database. Below is an example UserEntity, representing a user table:

@Entity(tableName = "user")
data class UserEntity(
    @PrimaryKey val id: Int = 0,
    @ColumnInfo("name") val name: String? = null,
)

Define Your DAO​

DAOs (Data Access Objects) define database operations. Below is an example UserDao:

@Dao
interface UserDao {
    
    @Query("SELECT * FROM user")
    fun getAllFlow(): Flow<List<UserEntity>>
    
    @Upsert
    suspend fun upsert(userEntity: UserEntity)
    
    @Delete
    suspend fun delete(userEntity: UserEntity)
}

Then, include your new DAO in the AppDatabase class:

abstract class AppDatabase : RoomDatabase() {
    abstract fun userDao(): UserDao
    // Add other DAOs here
}

For additional code examples, you can refer to ExampleEntity and ExampleDao, which contain more functions that you can copy and paste to quickly set up other entities and DAOs.

Accessing DAOs in Your Project​

To use DAOs within your application, you have two main options:

  1. Directly Passing AppDatabase: You can pass an instance of AppDatabase where needed and access the DAO directly, e.g., appDatabase.userDao().

  2. Injecting DAOs Directly (Recommended): It's generally best practice to inject individual DAOs rather than passing the entire database instance. This keeps different tables separate and provides better modularity.

Example of Injecting UserDao​

To inject UserDao, add it to your Dependency Injection (DI) setup:

single { get<AppDatabase>().userDao() }

For more details on setting up Dependency Injection, see the DI Setup.