Accessing routing path string within request in Ktor - kotlin

Question

Does the Ktor framework provide a way of accessing a route's path string within a request?
For example, if I set up a route such as:
routing {
get("/user/{user_id}") {
// possible to get the string "/user/{user_id}" here?
val path = someFunction()
assert(path == "/user/{user_id}")
}
}
To clarify, I'm looking for a way to access the unprocessed path string, i.e. "/user/{user_id}" in this case (accessing the path via call.request.path() gives me the path after the {user_id} has been filled in, e.g. "/user/123").
I can of course assign the path to a variable and pass it to both get and use it within the function body, but wondering if there's a way of getting at the route's path without doing that.

Answer 1

I don't think that is possible. What you could do instead is write such a class/object
object UserRoutes {
const val userDetails = "/users/{user_id}"
...
}
And reference that field from your routing module:
import package.UserRoutes
get(UserRoutes.userDetails) {...}
By doing so you would need to just reference that string from the given singleton. Also no need for the object wrapper but I think it looks neat that you can group the paths by somewhat their module name

Answer 2

I solved it like this
// Application.kt
private object Paths {
const val LOGIN = "/login"
...
}
fun Application.module(testing: Boolean = false) {
...
routing {
loginGet(Paths.LOGIN)
}
}
And to structure my extension functions, I put them in other files like this
// Auth.kt
fun Route.loginGet(path: String) = get(path) {
println("The path is: $path")
}

Answer 3

fun Route.fullPath(): String {
val parentPath = parent?.fullPath()?.let { if (it.endsWith("/")) it else "$it/" } ?: "/"
return when (selector) {
is TrailingSlashRouteSelector,
is AuthenticationRouteSelector -> parentPath
else -> parentPath + selector.toString()
}
}

Answer 4

I found a solution for this problem
val uri = "foos/foo"
get("$uri/{foo_id}") {
val path = call.request.path()
val firstPart = path.length
val secondPart = path.slice((firstPart+1) until path.length)
call.respondText("$secondPart")
}
try this code it's simple and robust

Answer 5

So all solutions so far miss the most obvious (and in my humble opinion - correct) way to extract the path variables:
routing {
get("/user/{user_id}") {
val userId = call.parameters["user_id"]
}
}
call.parameters["user_id"] will return a value of type String?
You can have multiple path variables and pull them out by this method.