hi, folks! I have a question about

is

checks and delegation from a class to an object. Ktor has an extension function on

ApplicationRequest

that uses

when(this)

to check if the request

is

a

ServletApplicationRequest

. The problem is that the actual request object that I call the extension function on, is a

RoutingApplicationRequest

, which is a class that delegates to the original request object. Which in turn causes

is ServletApplicationRequest

to be false, as

is

only seems to check class inheritance hierarchies, and not delegation. Is there a way to work around this? Or is it an issue/bug that Ktor needs to handle differently to work as expected? FYI, here’s the full extension function:

public val ApplicationRequest.javaSecurityPrincipal: Principal?
    get() = when (this) {
        is ServletApplicationRequest -> servletRequest.userPrincipal
        else -> null
    }

and here’s the class that the instance of the request object is a member of:

public class RoutingApplicationRequest(
    override val call: RoutingApplicationCall,
    override val pipeline: ApplicationReceivePipeline,
    request: ApplicationRequest
) : ApplicationRequest by request

A

ServletApplicationRequest

is a

ApplicationRequest

, but the inverse isn't necessarily true.

seems like this is an issue that needs to be fixed by ktor - there’s no way to access the original servlet request the way Ktor wraps it and delegates to it. I filed an issue 🙂 https://youtrack.jetbrains.com/issue/KTOR-4784

You could probably solve it with a slight workaround:

public val RoutingApplicationRequest.routedJavaSecurityPrincipal: Principal?
    get() = when (this.request) {
        is ServletApplicationRequest -> (this.request as ServletApplicationRequest).javaSecurityPrincipal
        else -> null
    }