IssueTracker

Component used: Navigation

Version used: 2.6.0-alpha01

Right now when providing a custom type half of the serialization/deserialization logic need to live in the NavType, but the other half, serializing the value into the route to call navigate with, is completely separate:

val SearchParametersType = object : NavType<SearchParameters>(
  isNullableAllowed = false
) {
  // ...

  override fun parseValue(value: String): SearchParameters {
    return Json.decodeFromString<SearchParameters>(value)
  }
}

and later

val params = SearchParameters("rose", listOf("available"))
val searchArgument = Uri.encode(Json.encodeToString(params))
navController.navigate("${nav_routes.plant_search}/$searchArgument")

It would be nice if NavType could be the single source of truth for both sides of the equation, thus allowing you to write something like:

override fun serializeAsValue(value: SearchParameters): String {
  return Uri.encode(Json.encodeToString(value))
}

And use it like:

val params = SearchParameters("rose", listOf("available"))
val searchArgument = SearchParametersType.serializeAsValue(params)
navController.navigate("${nav_routes.plant_search}/$searchArgument")

By default, I think this method should just call toString() on the class. The one exception could be StringType, which could Uri.encode() for you.