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Custom storage adapter¶

Use this when you already have a preference layer in your app (Sandook, MMKV, encrypted prefs, a key-value store via Ktor, etc.) and don't want to add another one.

Implement `PermissionStore`¶

class MyAppPermissionStore(
    private val prefs: MyAppPrefs,
) : PermissionStore {

    override suspend fun getRequestCount(p: AppPermission): Int =
        prefs.getInt("aagya.requestCount.${p.key}", default = 0)

    override suspend fun incrementRequestCount(p: AppPermission) {
        val key = "aagya.requestCount.${p.key}"
        prefs.setInt(key, prefs.getInt(key, default = 0) + 1)
    }

    override suspend fun reset(p: AppPermission) {
        prefs.remove("aagya.requestCount.${p.key}")
    }
}

Pass it into the policy¶

@Composable
fun App() {
    val store = remember { MyAppPermissionStore(prefs = MyAppPrefs.get()) }
    val controller = rememberPermissionController(
        policy = PermissionPolicy(
            maxRequestsAndroid = 1,
            maxRequestsIos = 1,
            store = store,
        ),
    )
    // ...
}

Contract reminders¶

All methods must be safe to call from any coroutine.
Implementations must be safe under concurrent reads and writes for the same key.
Methods must not throw across the public boundary. If your underlying store can fail, catch the exception, log it, and treat the read as 0.

Choosing a key prefix¶

The permission.key field is intentionally short and stable (location.fine, location.coarse). Prefix it with something namespace-y like aagya.requestCount. to avoid collisions with your app's other preference keys.

Testing your store¶

Aagya's own InMemoryPermissionStore is a good reference implementation. Run the same correctness checks against your store:

@Test
fun newStoreReportsZero() = runTest {
    val store = MyAppPermissionStore(prefs = TestPrefs())
    assertEquals(0, store.getRequestCount(AppPermission.Location.Fine))
}

@Test
fun incrementCountsForOnePermissionOnly() = runTest {
    val store = MyAppPermissionStore(prefs = TestPrefs())
    store.incrementRequestCount(AppPermission.Location.Fine)
    store.incrementRequestCount(AppPermission.Location.Fine)
    assertEquals(2, store.getRequestCount(AppPermission.Location.Fine))
    assertEquals(0, store.getRequestCount(AppPermission.Location.Coarse))
}