How to expose swagger UI with http4k?

I'm building a microservice with the http4k framework using their Contract APIs. I can easily expose the swagger API description JSON on eg. /swagger.json with

fun app(): HttpHandler = "/" bind contract {
    renderer = OpenApi3(ApiInfo("GoOut Locations API", "1.0"), Jackson)
    descriptionPath = "/swagger.json"
    routes += ...
}

Is there an easy way to expose the swagger UI so that 1) I can specify the path it will be available on. (eg. /swagger-ui) 2) The UI will be preconfigured to fetch the description JSON from the descriptionPath specified above.

An ideal API would look something like

fun app(): HttpHandler = "/" bind contract {
    renderer = OpenApi3(ApiInfo("GoOut Locations API", "1.0"), Jackson)
    descriptionPath = "/swagger.json"
    uiPath = "/swagger-ui"
    routes += ...
}

Solution

As of http4k 4.28.1.0, there is now a way to do this. See the following code taken from this documentation page:

package guide.howto.create_a_swagger_ui

import org.http4k.contract.contract
import org.http4k.contract.meta
import org.http4k.contract.openapi.ApiInfo
import org.http4k.contract.openapi.v3.OpenApi3
import org.http4k.contract.ui.swaggerUi
import org.http4k.core.Body
import org.http4k.core.ContentType
import org.http4k.core.Method.GET
import org.http4k.core.Request
import org.http4k.core.Response
import org.http4k.core.Status.Companion.OK
import org.http4k.core.Uri
import org.http4k.core.with
import org.http4k.lens.string
import org.http4k.routing.routes
import org.http4k.server.SunHttp
import org.http4k.server.asServer

fun main() {
    val greetingLens = Body.string(ContentType.TEXT_PLAIN).toLens()

    // Define a single http route for our contract
    val helloHandler = "/v1/hello" meta {
        operationId = "v1Hello"
        summary = "Say Hello"
        returning(OK, greetingLens to "Sample Greeting")
    } bindContract GET to { _: Request ->
        Response(OK).with(greetingLens of "HI!")
    }

    // Define a contract, and render an OpenApi 3 spec at "/spec"
    val v1Api = contract {
        routes += helloHandler
        renderer = OpenApi3(
            ApiInfo("Hello Server - Developer UI", "99.3.4")
        )
        descriptionPath = "spec"
    }

    // Build a Swagger UI based on the OpenApi spec defined at "/spec"
    val ui = swaggerUi(
        Uri.of("spec"),
        title = "Hello Server",
        displayOperationId = true
    )

    // Combine our api, spec, and ui; then start a server
    // The Swagger UI is available on the root "/" path
    routes(v1Api, ui)
        .asServer(SunHttp(8080))
        .start()
        .block()
}