Add more KDocs and nav args encoding

app/src/main/java/com/google/samples/apps/nowinandroid/ui/NiaAppState.kt

@@ -67,6 +67,9 @@ class NiaAppState(
     val shouldShowNavRail: Boolean
         get() = !shouldShowBottomBar
 
+    /**
+     * Top level destinations to be used in the BottomBar and NavRail
+     */
     val topLevelDestinations: List<TopLevelDestination> = listOf(
         TopLevelDestination(
             route = ForYouDestination.route,
@@ -84,10 +87,19 @@ class NiaAppState(
         )
     )
 
-    // --------------------
-    // NAVIGATION LOGIC
-    // --------------------
-
+    /**
+     * UI logic for navigating to a particular destination in the app. The NavigationOptions to
+     * navigate with are based on the type of destination, which could be a top level destination or
+     * just a regular destination.
+     *
+     * Top level destinations have only one copy of the destination of the back stack, and save and
+     * restore state whenever you navigate to and from it.
+     * Regular destinations can have multiple copies in the back stack and state isn't saved nor
+     * restored.
+     *
+     * @param destination: The [NiaNavigationDestination] the app needs to navigate to.
+     * @param route: Optional route to navigate to in case the destination contains arguments.
+     */
     fun navigate(destination: NiaNavigationDestination, route: String? = null) {
         trace("Navigation: $destination") {
             if (destination is TopLevelDestination) {
@@ -115,6 +127,9 @@ class NiaAppState(
     }
 }
 
+/**
+ * Stores information about navigation events to be used with JankStats
+ */
 @Composable
 private fun NavigationTrackingSideEffect(navController: NavHostController) {
     JankMetricDisposableEffect(navController) { metricsHolder ->

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

@@ -16,6 +16,7 @@
 
 package com.google.samples.apps.nowinandroid.feature.author.navigation
 
+import android.net.Uri
 import androidx.navigation.NavBackStackEntry
 import androidx.navigation.NavGraphBuilder
 import androidx.navigation.NavType
@@ -29,12 +30,20 @@ object AuthorDestination : NiaNavigationDestination {
     override val route = "author_route/{$authorIdArg}"
     override val destination = "author_destination"
 
+    /**
+     * Creates destination route for an authorId that could include special characters
+     */
     fun createNavigationRoute(authorIdArg: String): String {
-        return "author_route/$authorIdArg"
+        val encodedId = Uri.encode(authorIdArg)
+        return "author_route/$encodedId"
     }
 
+    /**
+     * Returns the authorId from a [NavBackStackEntry] after an author destination navigation call
+     */
     fun fromNavArgs(entry: NavBackStackEntry): String {
-        return entry.arguments?.getString(authorIdArg)!!
+        val encodedId = entry.arguments?.getString(authorIdArg)!!
+        return Uri.decode(encodedId)
     }
 }
 

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

@@ -16,6 +16,7 @@
 
 package com.google.samples.apps.nowinandroid.feature.topic.navigation
 
+import android.net.Uri
 import androidx.navigation.NavBackStackEntry
 import androidx.navigation.NavGraphBuilder
 import androidx.navigation.NavType
@@ -29,12 +30,20 @@ object TopicDestination : NiaNavigationDestination {
     override val route = "topic_route/{$topicIdArg}"
     override val destination = "topic_destination"
 
+    /**
+     * Creates destination route for a topicId that could include special characters
+     */
     fun createNavigationRoute(topicIdArg: String): String {
-        return "topic_route/$topicIdArg"
+        val encodedId = Uri.encode(topicIdArg)
+        return "topic_route/$encodedId"
     }
 
+    /**
+     * Returns the topicId from a [NavBackStackEntry] after a topic destination navigation call
+     */
     fun fromNavArgs(entry: NavBackStackEntry): String {
-        return entry.arguments?.getString(topicIdArg)!!
+        val encodedId = entry.arguments?.getString(topicIdArg)!!
+        return Uri.decode(encodedId)
     }
 }