Permissions with Flow API Examples
A step by step Permissions with Flow API example.
Permission Flow Android
Know about real-time state of a Android app Permissions with Kotlin Flow APIs..
It's a simple and easy to use library. Just Plug and Play. Follow these steps:
1. Step 1: Gradle setup
In build.gradle of app module, include this dependency
dependencies {
implementation "dev.shreyaspatil.permission-flow:permission-flow-android:$version"
// For using in Jetpack Compose
implementation "dev.shreyaspatil.permission-flow:permission-flow-compose:$version"
}
Step 2: Initialization
class MyApplication: Application() {
override fun onCreate() {
super.onCreate()
PermissionFlow.init(this)
}
}
Step 3. Observing a Permission State
3.1 Observing Permission with StateFlow
StateFlow - A permission state can be subscribed by retrieving StateFlow<PermissionState> or StateFlow<MultiplePermissionState> as follows:
val permissionFlow = PermissionFlow.getInstance()
// Observe state of single permission
suspend fun observePermission() {
permissionFlow.getPermissionState(android.Manifest.permission.READ_CONTACTS).collect { state ->
if (state.isGranted) {
// Do something
}
}
}
// Observe state of multiple permissions
suspend fun observeMultiplePermissions() {
permissionFlow.getMultiplePermissionState(
android.Manifest.permission.READ_CONTACTS,
android.Manifest.permission.READ_SMS
).collect { state ->
// All permission states
val allPermissions = state.permissions
// Check whether all permissions are granted
val allGranted = state.allGranted
// List of granted permissions
val grantedPermissions = state.grantedPermissions
// List of denied permissions
val deniedPermissions = state.deniedPermissions
}
}
3.2 Observing permissions in Jetpack Compose
State of a permission and state of multiple permissions can also be observed in Jetpack Compose application as follows:
@Composable
fun ExampleSinglePermission() {
val state by rememberPermissionState(Manifest.permission.CAMERA)
if (state.isGranted) {
// Render something
} else {
// Render something else
}
}
@Composable
fun ExampleMultiplePermission() {
val state by rememberMultiplePermissionState(
Manifest.permission.CAMERA
Manifest.permission.ACCESS_FINE_LOCATION,
Manifest.permission.READ_CONTACTS
)
if (state.allGranted) {
// Render something
}
val grantedPermissions = state.grantedPermissions
// Do something with `grantedPermissions`
val deniedPermissions = state.deniedPermissions
// Do something with `deniedPermissions`
}
4. Requesting permission with PermissionFlow
4.1 Request permission from Activity / Fragment
registerForPermissionFlowRequestsResult():
class ContactsActivity : AppCompatActivity() {
private val permissionLauncher = registerForPermissionFlowRequestsResult()
private fun askContactsPermission() {
permissionLauncher.launch(Manifest.permission.READ_CONTACTS, ...)
}
}
4.2 Request permission in Jetpack Compose
rememberPermissionFlowRequestLauncher():
@Composable
fun Example() {
val permissionLauncher = rememberPermissionFlowRequestLauncher()
Button(onClick = { permissionLauncher.launch(android.Manifest.permission.CAMERA, ...) }) {
Text("Request Permissions")
}
}
5. Manually notifying permission state changes ⚠️
PermissionFlow#notifyPermissionsChanged():
For example:
class MyActivity: AppCompatActivity() {
private val permissionFlow = PermissionFlow.getInstance()
private val permissionLauncher = registerForActivityResult(RequestPermission()) { isGranted ->
permissionFlow.notifyPermissionsChanged(android.Manifest.permission.READ_CONTACTS)
}
}
6. Manually Start / Stop Listening ⚠️
fun doSomething() {
// Stops listening to the state changes of permissions throughout the application.
// This means the state of permission retrieved with [getMultiplePermissionState] method will not
// be updated after stopping listening.
permissionFlow.stopListening()
// Starts listening the changes of state of permissions after stopping listening
permissionFlow.startListening()
}