Build a Product Management Android App with Jetpack Compose

This tutorial demonstrates how to build a basic product management app. The app demonstrates management operations, photo upload, account creation and authentication using:

Supabase Database - a Postgres database for storing your user data and Row Level Security so data is protected and users can only access their own information.
Supabase Auth - users log in through magic links sent to their email (without having to set up a password).
Supabase Storage - users can upload a profile photo.

If you get stuck while working through this guide, refer to the full example on GitHub.

</Admonition>

<$Partial path="kotlin_project_setup.mdx" variables={{ "framework": "androidkotlin", "tab": "mobiles" }} />

Building the app

Create new Android project

Open Android Studio > New Project > Base Activity (Jetpack Compose).

Set up API key and secret securely

Create local environment secret

Create or edit the local.properties file at the root (same level as build.gradle) of your project.

Note: Do not commit this file to your source control, for example, by adding it to your .gitignore file!

kotlin

SUPABASE_PUBLISHABLE_KEY=YOUR_SUPABASE_PUBLISHABLE_KEY
SUPABASE_URL=YOUR_SUPABASE_URL

Read and set value to `BuildConfig`

In your build.gradle (app) file, create a Properties object and read the values from your local.properties file by calling the buildConfigField method:

kotlin

defaultConfig {
   applicationId "com.example.manageproducts"
   minSdkVersion 22
   targetSdkVersion 33
   versionCode 5
   versionName "1.0"
   testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"

   // Set value part
   Properties properties = new Properties()
   properties.load(project.rootProject.file("local.properties").newDataInputStream())
   buildConfigField("String", "SUPABASE_PUBLISHABLE_KEY", "\"${properties.getProperty("SUPABASE_PUBLISHABLE_KEY")}\"")
   buildConfigField("String", "SECRET", "\"${properties.getProperty("SECRET")}\"")
   buildConfigField("String", "SUPABASE_URL", "\"${properties.getProperty("SUPABASE_URL")}\"")
}

Use value from `BuildConfig`

Read the value from BuildConfig:

kotlin

val url = BuildConfig.SUPABASE_URL
val apiKey = BuildConfig.SUPABASE_PUBLISHABLE_KEY

Set up Supabase dependencies

In the build.gradle (app) file, add these dependencies then press "Sync now." Replace the dependency version placeholders $supabase_version and $ktor_version with their respective latest versions.

kotlin

implementation "io.github.jan-tennert.supabase:postgrest-kt:$supabase_version"
implementation "io.github.jan-tennert.supabase:storage-kt:$supabase_version"
implementation "io.github.jan-tennert.supabase:auth-kt:$supabase_version"
implementation "io.ktor:ktor-client-android:$ktor_version"
implementation "io.ktor:ktor-client-core:$ktor_version"
implementation "io.ktor:ktor-utils:$ktor_version"

Also in the build.gradle (app) file, add the plugin for serialization. The version of this plugin should be the same as your Kotlin version.

kotlin

plugins {
    ...
    id 'org.jetbrains.kotlin.plugin.serialization' version '$kotlin_version'
    ...
}

Set up Hilt for dependency injection

In the build.gradle (app) file, add the following:

kotlin

implementation "com.google.dagger:hilt-android:$hilt_version"
annotationProcessor "com.google.dagger:hilt-compiler:$hilt_version"
implementation("androidx.hilt:hilt-navigation-compose:1.0.0")

Create a new ManageProductApplication.kt class extending Application with @HiltAndroidApp annotation:

kotlin

// ManageProductApplication.kt
@HiltAndroidApp
class ManageProductApplication: Application()

Open the AndroidManifest.xml file, update name property of Application tag:

xml

<application
...
    android:name=".ManageProductApplication"
...
</application>

Create the MainActivity:

kotlin

@AndroidEntryPoint
class MainActivity : ComponentActivity() {
    //This will come later
}

Provide Supabase instances with Hilt

To make the app easier to test, create a SupabaseModule.kt file as follows:

kotlin

@InstallIn(SingletonComponent::class)
@Module
object SupabaseModule {

    @Provides
    @Singleton
    fun provideSupabaseClient(): SupabaseClient {
        return createSupabaseClient(
            supabaseUrl = BuildConfig.SUPABASE_URL,
            supabaseKey = BuildConfig.SUPABASE_PUBLISHABLE_KEY
        ) {
            install(Postgrest)
            install(Auth) {
                flowType = FlowType.PKCE
                scheme = "app"
                host = "supabase.com"
            }
            install(Storage)
        }
    }

    @Provides
    @Singleton
    fun provideSupabaseDatabase(client: SupabaseClient): Postgrest {
        return client.postgrest
    }

    @Provides
    @Singleton
    fun provideSupabaseAuth(client: SupabaseClient): Auth {
        return client.auth
    }


    @Provides
    @Singleton
    fun provideSupabaseStorage(client: SupabaseClient): Storage {
        return client.storage
    }

}

Create a data transfer object

Create a ProductDto.kt class and use annotations to parse data from Supabase:

kotlin

@Serializable
data class ProductDto(

    @SerialName("name")
    val name: String,

    @SerialName("price")
    val price: Double,

    @SerialName("image")
    val image: String?,

    @SerialName("id")
    val id: String,
)

Create a Domain object in Product.kt expose the data in your view:

kotlin

data class Product(
    val id: String,
    val name: String,
    val price: Double,
    val image: String?
)

Implement repositories

Create a ProductRepository interface and its implementation named ProductRepositoryImpl. This holds the logic to interact with data sources from Supabase. Do the same with the AuthenticationRepository.

Create the Product Repository:

kotlin

interface ProductRepository {
    suspend fun createProduct(product: Product): Boolean
    suspend fun getProducts(): List<ProductDto>?
    suspend fun getProduct(id: String): ProductDto
    suspend fun deleteProduct(id: String)
    suspend fun updateProduct(
        id: String, name: String, price: Double, imageName: String, imageFile: ByteArray
    )
}

kotlin

class ProductRepositoryImpl @Inject constructor(
    private val postgrest: Postgrest,
    private val storage: Storage,
) : ProductRepository {
    override suspend fun createProduct(product: Product): Boolean {
        return try {
            withContext(Dispatchers.IO) {
                val productDto = ProductDto(
                    name = product.name,
                    price = product.price,
                )
                postgrest.from("products").insert(productDto)
                true
            }
            true
        } catch (e: java.lang.Exception) {
            throw e
        }
    }

    override suspend fun getProducts(): List<ProductDto>? {
        return withContext(Dispatchers.IO) {
            val result = postgrest.from("products")
                .select().decodeList<ProductDto>()
            result
        }
    }


    override suspend fun getProduct(id: String): ProductDto {
        return withContext(Dispatchers.IO) {
            postgrest.from("products").select {
                filter {
                    eq("id", id)
                }
            }.decodeSingle<ProductDto>()
        }
    }

    override suspend fun deleteProduct(id: String) {
        return withContext(Dispatchers.IO) {
            postgrest.from("products").delete {
                filter {
                    eq("id", id)
                }
            }
        }
    }

    override suspend fun updateProduct(
        id: String,
        name: String,
        price: Double,
        imageName: String,
        imageFile: ByteArray
    ) {
        withContext(Dispatchers.IO) {
            if (imageFile.isNotEmpty()) {
                val imageUrl =
                    storage.from("Product%20Image").upload(
                        path = "$imageName.png",
                        data = imageFile,
                        upsert = true
                    )
                postgrest.from("products").update({
                    set("name", name)
                    set("price", price)
                    set("image", buildImageUrl(imageFileName = imageUrl))
                }) {
                    filter {
                        eq("id", id)
                    }
                }
            } else {
                postgrest.from("products").update({
                    set("name", name)
                    set("price", price)
                }) {
                    filter {
                        eq("id", id)
                    }
                }
            }
        }
    }

    // Because I named the bucket as "Product Image" so when it turns to an url, it is "%20"
    // For better approach, you should create your bucket name without space symbol
    private fun buildImageUrl(imageFileName: String) =
        "${BuildConfig.SUPABASE_URL}/storage/v1/object/public/${imageFileName}".replace(" ", "%20")
}

Create the Authentication Repository:

kotlin

interface AuthenticationRepository {
    suspend fun signIn(email: String, password: String): Boolean
    suspend fun signUp(email: String, password: String): Boolean
    suspend fun signInWithGoogle(): Boolean
}

kotlin

class AuthenticationRepositoryImpl @Inject constructor(
    private val auth: Auth
) : AuthenticationRepository {
    override suspend fun signIn(email: String, password: String): Boolean {
        return try {
            auth.signInWith(Email) {
                this.email = email
                this.password = password
            }
            true
        } catch (e: Exception) {
            false
        }
    }

    override suspend fun signUp(email: String, password: String): Boolean {
        return try {
            auth.signUpWith(Email) {
                this.email = email
                this.password = password
            }
            true
        } catch (e: Exception) {
            false
        }
    }

    override suspend fun signInWithGoogle(): Boolean {
        return try {
            auth.signInWith(Google)
            true
        } catch (e: Exception) {
            false
        }
    }
}

Implement screens

To navigate screens, use the AndroidX navigation library. For routes, implement a Destination interface:

kotlin


interface Destination {
    val route: String
    val title: String
}


object ProductListDestination : Destination {
    override val route = "product_list"
    override val title = "Product List"
}

object ProductDetailsDestination : Destination {
    override val route = "product_details"
    override val title = "Product Details"
    const val productId = "product_id"
    val arguments = listOf(navArgument(name = productId) {
        type = NavType.StringType
    })
    fun createRouteWithParam(productId: String) = "$route/${productId}"
}

object AddProductDestination : Destination {
    override val route = "add_product"
    override val title = "Add Product"
}

object AuthenticationDestination: Destination {
    override val route = "authentication"
    override val title = "Authentication"
}

object SignUpDestination: Destination {
    override val route = "signup"
    override val title = "Sign Up"
}

This will help later for navigating between screens.

Create a ProductListViewModel:

kotlin

@HiltViewModel
class ProductListViewModel @Inject constructor(
private val productRepository: ProductRepository,
) : ViewModel() {

    private val _productList = MutableStateFlow<List<Product>?>(listOf())
    val productList: Flow<List<Product>?> = _productList


    private val _isLoading = MutableStateFlow(false)
    val isLoading: Flow<Boolean> = _isLoading

    init {
        getProducts()
    }

    fun getProducts() {
        viewModelScope.launch {
            val products = productRepository.getProducts()
            _productList.emit(products?.map { it -> it.asDomainModel() })
        }
    }

    fun removeItem(product: Product) {
        viewModelScope.launch {
            val newList = mutableListOf<Product>().apply { _productList.value?.let { addAll(it) } }
            newList.remove(product)
            _productList.emit(newList.toList())
            // Call api to remove
            productRepository.deleteProduct(id = product.id)
            // Then fetch again
            getProducts()
        }
    }

    private fun ProductDto.asDomainModel(): Product {
        return Product(
            id = this.id,
            name = this.name,
            price = this.price,
            image = this.image
        )
    }

}

Create the ProductListScreen.kt:

kotlin

@OptIn(ExperimentalMaterial3Api::class, ExperimentalMaterialApi::class)
@Composable
fun ProductListScreen(
    modifier: Modifier = Modifier,
    navController: NavController,
    viewModel: ProductListViewModel = hiltViewModel(),
) {
    val isLoading by viewModel.isLoading.collectAsState(initial = false)
    val swipeRefreshState = rememberSwipeRefreshState(isRefreshing = isLoading)
    SwipeRefresh(state = swipeRefreshState, onRefresh = { viewModel.getProducts() }) {
        Scaffold(
            topBar = {
                TopAppBar(
                    backgroundColor = MaterialTheme.colorScheme.primary,
                    title = {
                        Text(
                            text = stringResource(R.string.product_list_text_screen_title),
                            color = MaterialTheme.colorScheme.onPrimary,
                        )
                    },
                )
            },
            floatingActionButton = {
                AddProductButton(onClick = { navController.navigate(AddProductDestination.route) })
            }
        ) { padding ->
            val productList = viewModel.productList.collectAsState(initial = listOf()).value
            if (!productList.isNullOrEmpty()) {
                LazyColumn(
                    modifier = modifier.padding(padding),
                    contentPadding = PaddingValues(5.dp)
                ) {
                    itemsIndexed(
                        items = productList,
                        key = { _, product -> product.name }) { _, item ->
                        val state = rememberDismissState(
                            confirmStateChange = {
                                if (it == DismissValue.DismissedToStart) {
                                    // Handle item removed
                                    viewModel.removeItem(item)
                                }
                                true
                            }
                        )
                        SwipeToDismiss(
                            state = state,
                            background = {
                                val color by animateColorAsState(
                                    targetValue = when (state.dismissDirection) {
                                        DismissDirection.StartToEnd -> MaterialTheme.colorScheme.primary
                                        DismissDirection.EndToStart -> MaterialTheme.colorScheme.primary.copy(
                                            alpha = 0.2f
                                        )
                                        null -> Color.Transparent
                                    }
                                )
                                Box(
                                    modifier = modifier
                                        .fillMaxSize()
                                        .background(color = color)
                                        .padding(16.dp),
                                ) {
                                    Icon(
                                        imageVector = Icons.Filled.Delete,
                                        contentDescription = null,
                                        tint = MaterialTheme.colorScheme.primary,
                                        modifier = modifier.align(Alignment.CenterEnd)
                                    )
                                }

                            },
                            dismissContent = {
                                ProductListItem(
                                    product = item,
                                    modifier = modifier,
                                    onClick = {
                                        navController.navigate(
                                            ProductDetailsDestination.createRouteWithParam(
                                                item.id
                                            )
                                        )
                                    },
                                )
                            },
                            directions = setOf(DismissDirection.EndToStart),
                        )
                    }
                }
            } else {
                Text("Product list is empty!")
            }

        }
    }
}

@Composable
private fun AddProductButton(
    modifier: Modifier = Modifier,
    onClick: () -> Unit,
) {
    FloatingActionButton(
        modifier = modifier,
        onClick = onClick,
        containerColor = MaterialTheme.colorScheme.primary,
        contentColor = MaterialTheme.colorScheme.onPrimary
    ) {
        Icon(
            imageVector = Icons.Filled.Add,
            contentDescription = null,
        )
    }
}

Create the ProductDetailsViewModel.kt:

kotlin


@HiltViewModel
class ProductDetailsViewModel @Inject constructor(
    private val productRepository: ProductRepository,
    savedStateHandle: SavedStateHandle,
    ) : ViewModel() {

    private val _product = MutableStateFlow<Product?>(null)
    val product: Flow<Product?> = _product

    private val _name = MutableStateFlow("")
    val name: Flow<String> = _name

    private val _price = MutableStateFlow(0.0)
    val price: Flow<Double> = _price

    private val _imageUrl = MutableStateFlow("")
    val imageUrl: Flow<String> = _imageUrl

    init {
        val productId = savedStateHandle.get<String>(ProductDetailsDestination.productId)
        productId?.let {
            getProduct(productId = it)
        }
    }

    private fun getProduct(productId: String) {
        viewModelScope.launch {
           val result = productRepository.getProduct(productId).asDomainModel()
            _product.emit(result)
            _name.emit(result.name)
            _price.emit(result.price)
        }
    }

    fun onNameChange(name: String) {
        _name.value = name
    }

    fun onPriceChange(price: Double) {
        _price.value = price
    }

    fun onSaveProduct(image: ByteArray) {
        viewModelScope.launch {
            productRepository.updateProduct(
                id = _product.value?.id,
                price = _price.value,
                name = _name.value,
                imageFile = image,
                imageName = "image_${_product.value.id}",
            )
        }
    }

    fun onImageChange(url: String) {
        _imageUrl.value = url
    }

    private fun ProductDto.asDomainModel(): Product {
        return Product(
            id = this.id,
            name = this.name,
            price = this.price,
            image = this.image
        )
    }
}

Create the ProductDetailsScreen.kt:

kotlin

@OptIn(ExperimentalCoilApi::class)
@SuppressLint("UnusedMaterialScaffoldPaddingParameter")
@Composable
fun ProductDetailsScreen(
    modifier: Modifier = Modifier,
    viewModel: ProductDetailsViewModel = hiltViewModel(),
    navController: NavController,
    productId: String?,
) {
    val snackBarHostState = remember { SnackbarHostState() }
    val coroutineScope = rememberCoroutineScope()

    Scaffold(
        snackbarHost = { SnackbarHost(snackBarHostState) },
        topBar = {
            TopAppBar(
                navigationIcon = {
                    IconButton(onClick = {
                        navController.navigateUp()
                    }) {
                        Icon(
                            imageVector = Icons.Filled.ArrowBack,
                            contentDescription = null,
                            tint = MaterialTheme.colorScheme.onPrimary
                        )
                    }
                },
                backgroundColor = MaterialTheme.colorScheme.primary,
                title = {
                    Text(
                        text = stringResource(R.string.product_details_text_screen_title),
                        color = MaterialTheme.colorScheme.onPrimary,
                    )
                },
            )
        }
    ) {
        val name = viewModel.name.collectAsState(initial = "")
        val price = viewModel.price.collectAsState(initial = 0.0)
        var imageUrl = Uri.parse(viewModel.imageUrl.collectAsState(initial = null).value)
        val contentResolver = LocalContext.current.contentResolver

        Column(
            modifier = modifier
                .padding(16.dp)
                .fillMaxSize()
        ) {
            val galleryLauncher =
                rememberLauncherForActivityResult(ActivityResultContracts.GetContent())
                { uri ->
                    uri?.let {
                        if (it.toString() != imageUrl.toString()) {
                            viewModel.onImageChange(it.toString())
                        }
                    }
                }

            Image(
                painter = rememberImagePainter(imageUrl),
                contentScale = ContentScale.Fit,
                contentDescription = null,
                modifier = Modifier
                    .padding(16.dp, 8.dp)
                    .size(100.dp)
                    .align(Alignment.CenterHorizontally)
            )
            IconButton(modifier = modifier.align(alignment = Alignment.CenterHorizontally),
                onClick = {
                    galleryLauncher.launch("image/*")
                }) {
                Icon(
                    imageVector = Icons.Filled.Edit,
                    contentDescription = null,
                    tint = MaterialTheme.colorScheme.primary
                )
            }
            OutlinedTextField(
                label = {
                    Text(
                        text = "Product name",
                        color = MaterialTheme.colorScheme.primary,
                        style = MaterialTheme.typography.titleMedium
                    )
                },
                maxLines = 2,
                shape = RoundedCornerShape(32),
                modifier = modifier.fillMaxWidth(),
                value = name.value,
                onValueChange = {
                    viewModel.onNameChange(it)
                },
            )
            Spacer(modifier = modifier.height(12.dp))
            OutlinedTextField(
                label = {
                    Text(
                        text = "Product price",
                        color = MaterialTheme.colorScheme.primary,
                        style = MaterialTheme.typography.titleMedium
                    )
                },
                maxLines = 2,
                shape = RoundedCornerShape(32),
                modifier = modifier.fillMaxWidth(),
                value = price.value.toString(),
                keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Number),
                onValueChange = {
                    viewModel.onPriceChange(it.toDouble())
                },
            )
            Spacer(modifier = modifier.weight(1f))
            Button(
                modifier = modifier.fillMaxWidth(),
                onClick = {
                    if (imageUrl.host?.contains("supabase") == true) {
                        viewModel.onSaveProduct(image = byteArrayOf())
                    } else {
                        val image = uriToByteArray(contentResolver, imageUrl)
                        viewModel.onSaveProduct(image = image)
                    }
                    coroutineScope.launch {
                        snackBarHostState.showSnackbar(
                            message = "Product updated successfully !",
                            duration = SnackbarDuration.Short
                        )
                    }
                }) {
                Text(text = "Save changes")
            }
            Spacer(modifier = modifier.height(12.dp))
            OutlinedButton(
                modifier = modifier
                    .fillMaxWidth(),
                onClick = {
                    navController.navigateUp()
                }) {
                Text(text = "Cancel")
            }

        }

    }
}


private fun getBytes(inputStream: InputStream): ByteArray {
    val byteBuffer = ByteArrayOutputStream()
    val bufferSize = 1024
    val buffer = ByteArray(bufferSize)
    var len = 0
    while (inputStream.read(buffer).also { len = it } != -1) {
        byteBuffer.write(buffer, 0, len)
    }
    return byteBuffer.toByteArray()
}


private fun uriToByteArray(contentResolver: ContentResolver, uri: Uri): ByteArray {
    if (uri == Uri.EMPTY) {
        return byteArrayOf()
    }
    val inputStream = contentResolver.openInputStream(uri)
    if (inputStream != null) {
        return getBytes(inputStream)
    }
    return byteArrayOf()
}

Create a AddProductScreen:

kotlin

@SuppressLint("UnusedMaterial3ScaffoldPaddingParameter")
@OptIn(ExperimentalMaterial3Api::class)
@Composable
fun AddProductScreen(
    modifier: Modifier = Modifier,
    navController: NavController,
    viewModel: AddProductViewModel = hiltViewModel(),
) {
    Scaffold(
        topBar = {
            TopAppBar(
                navigationIcon = {
                    IconButton(onClick = {
                        navController.navigateUp()
                    }) {
                        Icon(
                            imageVector = Icons.Filled.ArrowBack,
                            contentDescription = null,
                            tint = MaterialTheme.colorScheme.onPrimary
                        )
                    }
                },
                backgroundColor = MaterialTheme.colorScheme.primary,
                title = {
                    Text(
                        text = stringResource(R.string.add_product_text_screen_title),
                        color = MaterialTheme.colorScheme.onPrimary,
                    )
                },
            )
        }
    ) { padding ->
        val navigateAddProductSuccess =
            viewModel.navigateAddProductSuccess.collectAsState(initial = null).value
        val isLoading =
            viewModel.isLoading.collectAsState(initial = null).value
        if (isLoading == true) {
            LoadingScreen(message = "Adding Product",
                onCancelSelected = {
                    navController.navigateUp()
                })
        } else {
            SuccessScreen(
                message = "Product added",
                onMoreAction = {
                    viewModel.onAddMoreProductSelected()
                },
                onNavigateBack = {
                    navController.navigateUp()
                })
        }

    }
}

Create the AddProductViewModel.kt:

kotlin

@HiltViewModel
class AddProductViewModel @Inject constructor(
    private val productRepository: ProductRepository,
) : ViewModel() {

    private val _isLoading = MutableStateFlow(false)
    val isLoading: Flow<Boolean> = _isLoading

    private val _showSuccessMessage = MutableStateFlow(false)
    val showSuccessMessage: Flow<Boolean> = _showSuccessMessage

    fun onCreateProduct(name: String, price: Double) {
        if (name.isEmpty() || price <= 0) return
        viewModelScope.launch {
            _isLoading.value = true
            val product = Product(
                id = UUID.randomUUID().toString(),
                name = name,
                price = price,
            )
            productRepository.createProduct(product = product)
            _isLoading.value = false
            _showSuccessMessage.emit(true)

        }
    }
}

Create a SignUpViewModel:

kotlin

@HiltViewModel
class SignUpViewModel @Inject constructor(
    private val authenticationRepository: AuthenticationRepository
) : ViewModel() {

    private val _email = MutableStateFlow("")
    val email: Flow<String> = _email

    private val _password = MutableStateFlow("")
    val password = _password

    fun onEmailChange(email: String) {
        _email.value = email
    }

    fun onPasswordChange(password: String) {
        _password.value = password
    }

    fun onSignUp() {
        viewModelScope.launch {
            authenticationRepository.signUp(
                email = _email.value,
                password = _password.value
            )
        }
    }
}

Create the SignUpScreen.kt:

kotlin

@Composable
fun SignUpScreen(
    modifier: Modifier = Modifier,
    navController: NavController,
    viewModel: SignUpViewModel = hiltViewModel()
) {
    val snackBarHostState = remember { SnackbarHostState() }
    val coroutineScope = rememberCoroutineScope()
    Scaffold(
        snackbarHost = { androidx.compose.material.SnackbarHost(snackBarHostState) },
        topBar = {
            TopAppBar(
                navigationIcon = {
                    IconButton(onClick = {
                        navController.navigateUp()
                    }) {
                        Icon(
                            imageVector = Icons.Filled.ArrowBack,
                            contentDescription = null,
                            tint = MaterialTheme.colorScheme.onPrimary
                        )
                    }
                },
                backgroundColor = MaterialTheme.colorScheme.primary,
                title = {
                    Text(
                        text = "Sign Up",
                        color = MaterialTheme.colorScheme.onPrimary,
                    )
                },
            )
        }
    ) { paddingValues ->
        Column(
            modifier = modifier
                .padding(paddingValues)
                .padding(20.dp)
        ) {
            val email = viewModel.email.collectAsState(initial = "")
            val password = viewModel.password.collectAsState()
            OutlinedTextField(
                label = {
                    Text(
                        text = "Email",
                        color = MaterialTheme.colorScheme.primary,
                        style = MaterialTheme.typography.titleMedium
                    )
                },
                maxLines = 1,
                shape = RoundedCornerShape(32),
                modifier = modifier.fillMaxWidth(),
                value = email.value,
                onValueChange = {
                    viewModel.onEmailChange(it)
                },
            )
            OutlinedTextField(
                label = {
                    Text(
                        text = "Password",
                        color = MaterialTheme.colorScheme.primary,
                        style = MaterialTheme.typography.titleMedium
                    )
                },
                maxLines = 1,
                shape = RoundedCornerShape(32),
                modifier = modifier
                    .fillMaxWidth()
                    .padding(top = 12.dp),
                value = password.value,
                onValueChange = {
                    viewModel.onPasswordChange(it)
                },
            )
            val localSoftwareKeyboardController = LocalSoftwareKeyboardController.current
            Button(modifier = modifier
                .fillMaxWidth()
                .padding(top = 12.dp),
                onClick = {
                    localSoftwareKeyboardController?.hide()
                    viewModel.onSignUp()
                    coroutineScope.launch {
                        snackBarHostState.showSnackbar(
                            message = "Create account successfully. Sign in now!",
                            duration = SnackbarDuration.Long
                        )
                    }
                }) {
                Text("Sign up")
            }
        }
    }
}

Create a SignInViewModel:

kotlin

@HiltViewModel
class SignInViewModel @Inject constructor(
    private val authenticationRepository: AuthenticationRepository
) : ViewModel() {

    private val _email = MutableStateFlow("")
    val email: Flow<String> = _email

    private val _password = MutableStateFlow("")
    val password = _password

    fun onEmailChange(email: String) {
        _email.value = email
    }

    fun onPasswordChange(password: String) {
        _password.value = password
    }

    fun onSignIn() {
        viewModelScope.launch {
            authenticationRepository.signIn(
                email = _email.value,
                password = _password.value
            )
        }
    }

    fun onGoogleSignIn() {
        viewModelScope.launch {
            authenticationRepository.signInWithGoogle()
        }
    }

}

Create the SignInScreen.kt:

kotlin

@OptIn(ExperimentalMaterial3Api::class, ExperimentalComposeUiApi::class)
@Composable
fun SignInScreen(
    modifier: Modifier = Modifier,
    navController: NavController,
    viewModel: SignInViewModel = hiltViewModel()
) {
    val snackBarHostState = remember { SnackbarHostState() }
    val coroutineScope = rememberCoroutineScope()
    Scaffold(
        snackbarHost = { androidx.compose.material.SnackbarHost(snackBarHostState) },
        topBar = {
            TopAppBar(
                navigationIcon = {
                    IconButton(onClick = {
                        navController.navigateUp()
                    }) {
                        Icon(
                            imageVector = Icons.Filled.ArrowBack,
                            contentDescription = null,
                            tint = MaterialTheme.colorScheme.onPrimary
                        )
                    }
                },
                backgroundColor = MaterialTheme.colorScheme.primary,
                title = {
                    Text(
                        text = "Login",
                        color = MaterialTheme.colorScheme.onPrimary,
                    )
                },
            )
        }
    ) { paddingValues ->
        Column(
            modifier = modifier
                .padding(paddingValues)
                .padding(20.dp)
        ) {
            val email = viewModel.email.collectAsState(initial = "")
            val password = viewModel.password.collectAsState()
            androidx.compose.material.OutlinedTextField(
                label = {
                    Text(
                        text = "Email",
                        color = MaterialTheme.colorScheme.primary,
                        style = MaterialTheme.typography.titleMedium
                    )
                },
                maxLines = 1,
                shape = RoundedCornerShape(32),
                modifier = modifier.fillMaxWidth(),
                value = email.value,
                onValueChange = {
                    viewModel.onEmailChange(it)
                },
            )
            androidx.compose.material.OutlinedTextField(
                label = {
                    Text(
                        text = "Password",
                        color = MaterialTheme.colorScheme.primary,
                        style = MaterialTheme.typography.titleMedium
                    )
                },
                maxLines = 1,
                shape = RoundedCornerShape(32),
                modifier = modifier
                    .fillMaxWidth()
                    .padding(top = 12.dp),
                value = password.value,
                onValueChange = {
                    viewModel.onPasswordChange(it)
                },
            )
            val localSoftwareKeyboardController = LocalSoftwareKeyboardController.current
            Button(modifier = modifier
                .fillMaxWidth()
                .padding(top = 12.dp),
                onClick = {
                    localSoftwareKeyboardController?.hide()
                    viewModel.onGoogleSignIn()
                }) {
                Text("Sign in with Google")
            }
            Button(modifier = modifier
                .fillMaxWidth()
                .padding(top = 12.dp),
                onClick = {
                    localSoftwareKeyboardController?.hide()
                    viewModel.onSignIn()
                    coroutineScope.launch {
                        snackBarHostState.showSnackbar(
                            message = "Sign in successfully !",
                            duration = SnackbarDuration.Long
                        )
                    }
                }) {
                Text("Sign in")
            }
            OutlinedButton(modifier = modifier
                .fillMaxWidth()
                .padding(top = 12.dp), onClick = {
                navController.navigate(SignUpDestination.route)
            }) {
                Text("Sign up")
            }
        }
    }
}

Implement the `MainActivity`

In the MainActivity you created earlier, show your newly created screens:

kotlin

@AndroidEntryPoint
class MainActivity : ComponentActivity() {
    @Inject
    lateinit var supabaseClient: SupabaseClient

    @OptIn(ExperimentalMaterial3Api::class)
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContent {
            ManageProductsTheme {
                // A surface container using the 'background' color from the theme
                val navController = rememberNavController()
                val currentBackStack by navController.currentBackStackEntryAsState()
                val currentDestination = currentBackStack?.destination
                Scaffold { innerPadding ->
                    NavHost(
                        navController,
                        startDestination = ProductListDestination.route,
                        Modifier.padding(innerPadding)
                    ) {
                        composable(ProductListDestination.route) {
                            ProductListScreen(
                                navController = navController
                            )
                        }

                        composable(AuthenticationDestination.route) {
                            SignInScreen(
                                navController = navController
                            )
                        }

                        composable(SignUpDestination.route) {
                            SignUpScreen(
                                navController = navController
                            )
                        }

                        composable(AddProductDestination.route) {
                            AddProductScreen(
                                navController = navController
                            )
                        }

                        composable(
                            route = "${ProductDetailsDestination.route}/{${ProductDetailsDestination.productId}}",
                            arguments = ProductDetailsDestination.arguments
                        ) { navBackStackEntry ->
                            val productId =
                                navBackStackEntry.arguments?.getString(ProductDetailsDestination.productId)
                            ProductDetailsScreen(
                                productId = productId,
                                navController = navController,
                            )
                        }
                    }
                }
            }
        }
    }
}

Create the success screen

To handle OAuth and OTP signins, create a new activity to handle the deep link you set in AndroidManifest.xml:

xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools">
    <uses-permission android:name="android.permission.INTERNET" />
    <application
        android:name=".ManageProductApplication"
        android:allowBackup="true"
        android:dataExtractionRules="@xml/data_extraction_rules"
        android:enableOnBackInvokedCallback="true"
        android:fullBackupContent="@xml/backup_rules"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/Theme.ManageProducts"
        tools:targetApi="31">
        <activity
            android:name=".DeepLinkHandlerActivity"
            android:exported="true"
            android:theme="@style/Theme.ManageProducts" >
            <intent-filter android:autoVerify="true">
                <action android:name="android.intent.action.VIEW" />
                <category android:name="android.intent.category.DEFAULT" />
                <category android:name="android.intent.category.BROWSABLE" />
                <data
                    android:host="supabase.com"
                    android:scheme="app" />
            </intent-filter>
        </activity>
        <activity
            android:name=".MainActivity"
            android:exported="true"
            android:label="@string/app_name"
            android:theme="@style/Theme.ManageProducts">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>
</manifest>

Then create the DeepLinkHandlerActivity:

kotlin

@AndroidEntryPoint
class DeepLinkHandlerActivity : ComponentActivity() {

    @Inject
    lateinit var supabaseClient: SupabaseClient

    private lateinit var callback: (String, String) -> Unit

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        supabaseClient.handleDeeplinks(intent = intent,
            onSessionSuccess = { userSession ->
                Log.d("LOGIN", "Log in successfully with user info: ${userSession.user}")
                userSession.user?.apply {
                    callback(email ?: "", createdAt.toString())
                }
            })
        setContent {
            val navController = rememberNavController()
            val emailState = remember { mutableStateOf("") }
            val createdAtState = remember { mutableStateOf("") }
            LaunchedEffect(Unit) {
                callback = { email, created ->
                    emailState.value = email
                    createdAtState.value = created
                }
            }
            ManageProductsTheme {
                Surface(
                    modifier = Modifier.fillMaxSize(),
                    color = MaterialTheme.colorScheme.background
                ) {
                    SignInSuccessScreen(
                        modifier = Modifier.padding(20.dp),
                        navController = navController,
                        email = emailState.value,
                        createdAt = createdAtState.value,
                        onClick = { navigateToMainApp() }
                    )
                }
            }
        }
    }

    private fun navigateToMainApp() {
        val intent = Intent(this, MainActivity::class.java).apply {
            flags = Intent.FLAG_ACTIVITY_CLEAR_TOP
        }
        startActivity(intent)
    }
}

Building the app

Create new Android project

Set up API key and secret securely

Create local environment secret

Read and set value to BuildConfig

Use value from BuildConfig

Set up Supabase dependencies

Set up Hilt for dependency injection

Provide Supabase instances with Hilt

Create a data transfer object

Implement repositories

Implement screens

Implement the MainActivity

Create the success screen

Read and set value to `BuildConfig`

Use value from `BuildConfig`

Implement the `MainActivity`