Add navigation route with argument contract

core-navigation/src/main/java/com/google/samples/apps/nowinandroid/core/navigation/NiaNavigationDestination.kt

@@ -36,3 +36,11 @@ interface NiaNavigationDestination {
      */
     val destination: String
 }
+
+interface NiaNavigationWithArguments {
+
+    /**
+     * Defines the arguments on the screen, which will be combined with the screen route.
+     */
+    val routeWithArguments: String
+}

feature-author/src/main/java/com/google/samples/apps/nowinandroid/feature/author/navigation/AuthorNavigation.kt

@@ -21,19 +21,23 @@ import androidx.navigation.NavType
 import androidx.navigation.compose.composable
 import androidx.navigation.navArgument
 import com.google.samples.apps.nowinandroid.core.navigation.NiaNavigationDestination
+import com.google.samples.apps.nowinandroid.core.navigation.NiaNavigationWithArguments
 import com.google.samples.apps.nowinandroid.feature.author.AuthorRoute
 
-object AuthorDestination : NiaNavigationDestination {
+object AuthorDestination : NiaNavigationDestination, NiaNavigationWithArguments {
     override val route = "author_route"
     override val destination = "author_destination"
     const val authorIdArg = "authorId"
+
+    override val routeWithArguments: String
+        get() = route.plus("/{$authorIdArg}")
 }
 
 fun NavGraphBuilder.authorGraph(
     onBackClick: () -> Unit
 ) {
     composable(
-        route = "${AuthorDestination.route}/{${AuthorDestination.authorIdArg}}",
+        route = AuthorDestination.routeWithArguments,
         arguments = listOf(
             navArgument(AuthorDestination.authorIdArg) {
                 type = NavType.StringType
@@ -42,4 +46,4 @@ fun NavGraphBuilder.authorGraph(
     ) {
         AuthorRoute(onBackClick = onBackClick)
     }
-}
+}

feature-topic/src/main/java/com/google/samples/apps/nowinandroid/feature/topic/navigation/TopicNavigation.kt

@@ -21,19 +21,23 @@ import androidx.navigation.NavType
 import androidx.navigation.compose.composable
 import androidx.navigation.navArgument
 import com.google.samples.apps.nowinandroid.core.navigation.NiaNavigationDestination
+import com.google.samples.apps.nowinandroid.core.navigation.NiaNavigationWithArguments
 import com.google.samples.apps.nowinandroid.feature.topic.TopicRoute
 
-object TopicDestination : NiaNavigationDestination {
+object TopicDestination : NiaNavigationDestination, NiaNavigationWithArguments {
     override val route = "topic_route"
     override val destination = "topic_destination"
     const val topicIdArg = "topicId"
+
+    override val routeWithArguments: String
+        get() = route.plus("/{$topicIdArg}")
 }
 
 fun NavGraphBuilder.topicGraph(
     onBackClick: () -> Unit
 ) {
     composable(
-        route = "${TopicDestination.route}/{${TopicDestination.topicIdArg}}",
+        route = TopicDestination.routeWithArguments,
         arguments = listOf(
             navArgument(TopicDestination.topicIdArg) {
                 type = NavType.StringType
@@ -42,4 +46,4 @@ fun NavGraphBuilder.topicGraph(
     ) {
         TopicRoute(onBackClick = onBackClick)
     }
-}
+}