problem-details-ktor/io.github.ilyankin.rfc9457.ktor/ProblemDetailsCatalog

ProblemDetailsCatalog

A declarative catalog of exception-to-problem and status-to-problem mappings.

Every entry becomes exactly one registration on Ktor's own StatusPages configuration; dispatch, including nearest-parent-class resolution, stays StatusPages's job. Obtain one through problemDetails, or through problemCatalog when something besides StatusPages needs it too. Configuration is limited to the builder block. Once returned, a catalog is immutable, so every consumer observes the same mappings.

Properties

problemTypes

val problemTypes: List<ProblemType>

The problem types declared through map with a ProblemType argument, in declaration order.

statusCodes

val statusCodes: Set<HttpStatusCode>

The status codes registered through forStatusCode, including via standardStatusCodes. The returned set is a snapshot and cannot change this catalog.

Functions

customize

fun customize(handler: (ApplicationCall, Problem) -> Problem)

Registers handler, run on every problem this catalog produces right before it is sent.

forStatusCode

fun forStatusCode(status: HttpStatusCode, provider: (ApplicationCall) -> Problem)

Registers a problem body for one status code.

map

inline fun <T : Throwable> map(noinline toProblem: (ApplicationCall, T) -> Problem)

Maps T to a problem built from the call and the exception.

inline fun <T : Throwable> map(type: ProblemType, noinline detailFrom: (T) -> String? = { it.message })

Maps T to type, taking detail from the exception message by default.

onUnmapped

fun onUnmapped(handler: (ApplicationCall, Throwable) -> Problem)

Replaces the problem produced for an exception no mapping covers.

standardStatusCodes

fun standardStatusCodes()

Covers the codes Ktor itself generates without an explicit body: 404, 405, 406, 415.