In this article, we will learn how to integrate a new library biometric-compose into Android applications for Biometric integration.
A new biometric-compose library simplifies the integration of biometrics into Compose-based applications.
Implementation
Dependencies
implementation("androidx.biometric:biometric:1.4.0-alpha06")
implementation("androidx.biometric:biometric-compose:1.4.0-alpha06")
rememberAuthenticationLauncher
- A composable function to streamline biometric authentication requests and callbacks directly in composables.
- It returns AuthenticationResultLauncher that we can use to initiate the authentication process.
- We need to pass a callback of type AuthenticationResultCallback . It will be called when an AuthenticationResult is available.
A successful or error result will be delivered to AuthenticationResultCallback.onAuthResult , and failures will be delivered to AuthenticationResultCallback.onAuthAttemptFailed, which is set by a callback.
The 👆callback will be executed on the main thread.
fun AuthenticationResult.processAuthResult(){
when (this) {
is AuthenticationResult.Success ->
Log.d(TAG, "AuthenticationResult Success, nAuth type: $authType, nCrypto object: $crypto")
is AuthenticationResult.Error ->
Log.d(TAG,"AuthenticationResult Error, nError code: $errorCode, nErr string: $errString")
is AuthenticationResult.CustomFallbackSelected -> {
Log.d(TAG,"AuthenticationResult CustomFallbackSelected ${fallback.text}")
}
}
}
AuthenticationResultType
AuthenticationError (Error code)
🧑💻 Code: rememberAuthenticationLauncher
val launcher =
rememberAuthenticationLauncher(
resultCallback =
object : AuthenticationResultCallback {
override fun onAuthResult(result: AuthenticationResult) {
Log.d(TAG, "onAuthResult: $result")
processAuthResult()
}
override fun onAuthAttemptFailed() {
super.onAuthAttemptFailed()
Log.d(TAG, "onAuthAttemptFailed: ")
}
}
)
🚀 Initiate the auth process
- Here we need to pass the AuthenticationRequest — It’s basically the configuration of the request. Like title, fallbacks, subtitle, icon, etc.
- In the following code, we are using the static function biometricRequest from AuthenticationRequest class to create a AuthenticationRequest
Button(
onClick = {
launcher.launch(
biometricRequest(
title = "Biometric auth..",
authFallbacks = arrayOf(AuthenticationRequest.Biometric.Fallback.DeviceCredential),
) {
// Optionally set the other configurations.
// setSubtitle(), setContent(), etc.
}
)
}
) {
Text(text = "Start Authentication")
}
👇Prompt without any customization based on the above 👆 implementation
Customization of the prompt
Subtitle
Button(
onClick = {
launcher.launch(
biometricRequest(
title = "Biometric auth..",
authFallbacks = arrayOf(AuthenticationRequest.Biometric.Fallback.DeviceCredential),
) {
setSubtitle("Subtitle goes here...")
}
)
}
) {
Text(text = "Start Authentication")
}
Logo
- This requires SET_BIOMETRIC_DIALOG_ADVANCED permission.
- This permission is granted only to system apps, so it would be better to let the library show the application’s logo in the prompt.
Button(
onClick = {
launcher.launch(
biometricRequest(
title = "Biometric auth..",
authFallbacks = arrayOf(AuthenticationRequest.Biometric.Fallback.DeviceCredential),
) {
setLogoRes(R.drawable.food_bank_24px)
//....
}
)
}
) {
Text(text = "Start Authentication")
}
Description
- setContent(content: BodyContent?) : A single parameter of type BodyContent will be used to display the description.
- BodyContent: It’s an abstract class, and we have the following 3 implementations that we can use
PlainText , VerticalList, & ContentViewWithMoreOptionsButton
ContentViewWithMoreOptionsButton : Requires SET_BIOMETRIC_DIALOG_ADVANCED
BodyContent class
public abstract class BodyContent private constructor() {
public class PlainText public constructor(public val description: String) : BodyContent()
public class VerticalList
@JvmOverloads
public constructor(
public val description: String? = null,
public val items: List<PromptContentItem> = listOf(),
) : BodyContent()
public class ContentViewWithMoreOptionsButton
@RequiresPermission(SET_BIOMETRIC_DIALOG_ADVANCED)
@JvmOverloads
public constructor(public val description: String? = null) : BodyContent()
}
Button(
onClick = {
launcher.launch(
biometricRequest(
title = "Biometric auth..",
authFallbacks = arrayOf(AuthenticationRequest.Biometric.Fallback.DeviceCredential),
) {
setContent(AuthenticationRequest.BodyContent.PlainText("Description"))
setContent(
AuthenticationRequest.BodyContent.VerticalList(
"Description",
listOf(
PromptContentItemPlainText("Item1..."),
PromptContentItemBulletedText("Bulleted item...")
)
)
)
}
)
}
) {
Text(text = "Start Authentication")
}
👇Prompt with custom subtitle, and description based on the above implementation 👆
Authfallbacks
- If we don’t provide any auth fallbacks when creating the AuthenticationRequest, the default cancel button will be shown in the prompt.
Button(
onClick = {
launcher.launch(
biometricRequest(
title = "Biometric auth.."
) {
// Configuration goes here,...
}
)
}
) {
Text(text = "Start Authentication")
}
References
Biometric | Jetpack | Android Developers
Stay in touch
https://www.linkedin.com/in/navczydev/
Biometric Auth in Compose Made Easy: The New Library You Need was originally published in ProAndroidDev on Medium, where people are continuing the conversation by highlighting and responding to this story.
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