AgentSkillsCN

datastore

使用 DataStore 实现简单的键值持久化。

SKILL.md
--- frontmatter
name: datastore
description: Work with DataStore for simple key-value persistence.
argument-hint: "[task] - e.g., 'create settings store', 'add preference', 'migrate from SharedPreferences'"
context: fork
allowed-tools: Read, Edit, Write, Bash(./format, ./gradlew *, grep, cat, mkdir), Glob, Grep

DataStore Skill

Work with DataStore for simple key-value persistence.

Common Tasks

code
/datastore create settings store        # Create new DataStore
/datastore add preference               # Add new preference key
/datastore explain patterns             # Understand DataStore patterns

When to Use DataStore

Use DataStore for:

  • •User preferences and settings
  • •Simple key-value data
  • •Small amounts of data

Use SQLDelight instead for:

  • •Structured relational data
  • •Large amounts of data
  • •Complex queries

DataStore Pattern

kotlin
@SingleIn(AppScope::class)
class SettingsDataStore @Inject constructor(
  @AppContext private val context: Context,
) {
  private val Context.dataStore by preferencesDataStore(name = "settings")

  val isDarkModeEnabled: Flow<Boolean> = context.dataStore.data
    .map { preferences ->
      preferences[DARK_MODE_KEY] ?: false
    }

  suspend fun setDarkModeEnabled(enabled: Boolean) {
    context.dataStore.edit { preferences ->
      preferences[DARK_MODE_KEY] = enabled
    }
  }

  companion object {
    private val DARK_MODE_KEY = booleanPreferencesKey("dark_mode")
  }
}

Key Patterns

Preference Keys

kotlin
val STRING_KEY = stringPreferencesKey("string_key")
val INT_KEY = intPreferencesKey("int_key")
val BOOL_KEY = booleanPreferencesKey("bool_key")
val LONG_KEY = longPreferencesKey("long_key")
val FLOAT_KEY = floatPreferencesKey("float_key")

Reading with Default

kotlin
val value: Flow<String> = dataStore.data
  .map { it[STRING_KEY] ?: "default" }

Writing

kotlin
suspend fun setValue(value: String) {
  dataStore.edit { it[STRING_KEY] = value }
}

Clearing

kotlin
suspend fun clear() {
  dataStore.edit { it.clear() }
}

Documentation