EasyStore

Auto generate boilerplate code for Androidx Preference Datastore with the help of KSP (Kotlin Symbol Processor

Features

✅ Supports Int, String Double, Boolean, Float, Long, Set<String>.

✅ Automatic mapping for Kotlin enum and Data class.

✍️ You write

@EasyStore
interface AppPreferences {

    @Store(preferenceKeyName = "app_theme")
    suspend fun updateTheme(theme: Theme)

    // Automatic Enum mapping (Also supports Data Class)
    @Retrieve(preferenceKeyName = "app_theme")
    fun getAppTheme(default: Theme): Flow<Theme>
}

🧑‍💻 EasyStore generates

public class AppPreferencesImpl(
  private val dataStore: DataStore<Preferences>,
) : AppPreferences {
  public override suspend fun updateTheme(theme: Theme): Unit {
    dataStore.edit { preferences ->
        preferences[APP_THEME_KEY] = theme.name
    }
  }
    
  public override fun getAppTheme(default: Theme): Flow<Theme> = dataStore.data
  .catch { exception ->
      if (exception is IOException) {
          emit(emptyPreferences())
      } else {
          throw exception
      }
  }.map { preference ->
      Theme.valueOf(preference[APP_THEME_KEY] ?: default.name)
  }
    
  private companion object {
    private val APP_THEME_KEY: Preferences.Key<String> = stringPreferencesKey("app_theme")
  }
}

🔥 Usage

// Single Instance of DataStore
private val Context.dataStore: DataStore<Preferences>
        by preferencesDataStore(name = "my_prefs")

class MainActivity : AppCompatActivity() {

    private val appPreferences: AppPreferences by lazy {
        // Impl generated by EasyStore
        AppPreferencesImpl(application.dataStore)
    }

    private lateinit var currentTheme: Theme

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        withRepeatOnLifecycle {
            appPreferences.getAppTheme(default = Theme.SYSTEM).collectLatest { theme ->
                currentTheme = theme
            }
        }
        
        private fun applyTheme(theme: Theme) {
            lifecycleScope.launch {
                appPreferences.updateTheme(theme)
            }
        }
    }
}

Guidelines

1. Create an interface and annotate it with @EasyStore.
2. Create two functions, one to store and other to retrieve, annotate it with @Store and @Retrieve respectively.
3. Make sure to have a return type of Flow<T> to the retrieve function.
4. Add a parameter/argument to the retrieve function with the same type you want to return (for default).

    @Retrieve(preferenceKeyName = "app_theme")
    fun getAppTheme(default: Theme): Flow<Theme>

5. Last but not the least, make sure the preferenceKeyName is same for both the retrieve and store function.

Checkout the official sample.

Gradle Setup

To use KSP (Kotlin Symbol Processing) and EasyStore library in your project, you need to follow steps below.

1. Enable KSP in your module

Add the KSP plugin below into your module's build.gradle file:

Kotlin (KTS)

plugins {
    id("com.google.devtools.ksp") version "1.7.10-1.0.6"
}

Groovy

plugins {
    id("com.google.devtools.ksp") version "1.7.10-1.0.6"
}

Note: Make sure your current Kotlin version and KSP version is the same.

2. Add EasyStore dependencies

Add the dependency below into your module's build.gradle file:

dependencies {
    // DataStore (Use the same version to avoid any conflicts)
    implementation("androidx.datastore:datastore-preferences:1.0.0")
    
    implementation("com.kasem-sm.easystore:core:0.0.4-alpha")
    ksp("com.kasem-sm.easystore:processor:0.0.4-alpha")
}

3. Add KSP source path

To access generated codes from KSP, you need to set up the source path like the below into your module's build.gradle file:

Android Kotlin (KTS)

kotlin {
  sourceSets.configureEach {
    kotlin.srcDir("$buildDir/generated/ksp/$name/kotlin/")
  }
}

Android Groovy

android {
    applicationVariants.all { variant ->
        kotlin.sourceSets {
            def name = variant.name
            getByName(name) {
                kotlin.srcDir("build/generated/ksp/$name/kotlin")
            }
        }
    }
}

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Contact 🤙

Direct Messages on My Twitter are always open. If you have any questions related to EasyStore or Android development, ping me anytime!

💎 Credits

• Gradle setup from skydoves's repo.
• Márton B's super-helpful article, Publishing Android libraries to MavenCentral in 2021.