by Ioannis Anifantakis
The NavHelper library provides utilities to enhance Jetpack Compose navigation with type safety for Parcelable objects and the serialization of strings with special characters using URL encoding and decoding. This library requires Navigation Component version 2.8.0-alpha08 or later.
While the Navigation Component version 2.8.0-alpha08 and later supports type safety out of the box for primitive types, passing Parcelable objects and handling strings with special characters require additional code. The NavHelper library provides this extra code, saving you from writing it manually for each project. It includes: Features
- Type-safe navigation for Parcelable objects.
- URL encoding and decoding for strings with special characters.
- Simplifies code required for passing Parcelables and serialized strings between screens.
- Add this to your dependencies
implementation("com.github.ioannisa:NavTypeParcelableHelperLibrary:1.0.1")- Add Jitpack as a dependencies repository in your
settings.gradle(or at Project'sbuild.gradlefor older Android projects) in order for this library to be able to download
repositories {
google()
mavenCentral()
maven(url = "https://jitpack.io") // <-- add this line
}StringSanitizer is a custom serializer for handling strings with special characters, including but not limited to URLs. This ensures that such strings are safely encoded and decoded, preventing issues with special characters in navigation parameters. This encoding can be applied to any string containing special characters, not just URLs, to ensure they do not break during the serialization phase.
import kotlinx.parcelize.Parcelize
import kotlinx.serialization.Serializable
import eu.anifantakis.navhelper.serialization.StringSanitizer
@Serializable
@Parcelize
data class Person(
val id: Int,
val section: Int,
val name: String,
@Serializable(with = StringSanitizer::class)
val imageUrl: String,
@Serializable(with = StringSanitizer::class)
val landingPage: String
) : ParcelableNavType.Companion.mapper provides a NavType for Parcelable objects, enabling type-safe navigation in Jetpack Compose. For the Parcelable class you want to pass, you just need to declare it using the typeMap named variable.
import android.os.Parcelable
import androidx.compose.runtime.Composable
import androidx.lifecycle.viewmodel.compose.viewModel
import androidx.navigation.NavType
import androidx.navigation.compose.NavHost
import androidx.navigation.compose.composable
import androidx.navigation.compose.rememberNavController
import eu.anifantakis.navhelper.navtype.mapper
import kotlinx.parcelize.Parcelize
import kotlinx.serialization.Serializable
import kotlin.reflect.typeOf
@Serializable
@Parcelize
data class Person(
val id: Int,
val section: Int,
val name: String,
@Serializable(with = StringSanitizer::class)
val imageUrl: String,
@Serializable(with = StringSanitizer::class)
val landingPage: String
) : Parcelable
sealed class NavRoute {
@Serializable
object MainScreen
@Serializable
data class DetailScreen(
val person: Person
)
}
@Composable
fun NavigationRootNew() {
val navController = rememberNavController()
NavHost(navController = navController, startDestination = NavRoute.MainScreen) {
composable<NavRoute.MainScreen> {
val viewModel = viewModel<MainScreenViewModel>()
MainScreen(viewModel, onItemClick = { person ->
navController.navigate(NavRoute.DetailScreen(person))
})
}
composable<NavRoute.DetailScreen>(
typeMap = mapOf(typeOf<Person>() to NavType.mapper<Person>())
) {
val person = it.toRoute<NavRoute.DetailScreen>().person
DetailScreen(person, onBackPress = {
navController.popBackStack()
})
}
}
}