Delegate RequestHandlerDelegate
Represents a request handler in the router pipeline.
Namespace: NanoRoute
Assembly: NanoRoute.dll
Syntax
public delegate Task<HttpResponseMessage> RequestHandlerDelegate(RequestContext requestContext, CallNextHandlerDelegate callNext)Parameters
| Type | Name | Description |
|---|---|---|
| RequestContext | requestContext | The current request context, including parsed route parameters, remaining path, and services. |
| CallNextHandlerDelegate | callNext | A delegate that invokes the next compatible handler in the pipeline. |
Returns
| Type | Description |
|---|---|
| Task<HttpResponseMessage> | The response produced by the current handler, or by a later handler when |
Remarks
Handler may signal HTTP failures by calling HttpRequestException.Throw(...). When
AddJsonErrorDetails<TBuilder>(TBuilder), or equivalent custom
middleware is registered, those exceptions can be translated into structured error responses. Use
ConfigureJsonErrorDetails<TBuilder>(TBuilder, ConfigureBuilderDelegate<JsonErrorDetailsConfig>)
before registering JSON error handling when you need to include developer diagnostics. Throwing other
exception types is also supported, but they are treated as unexpected failures:
AddExceptionHandler<TBuilder>(TBuilder) converts them into internal
server error responses, while without such middleware they propagate to the caller unchanged.
OperationCanceledException is left untouched so caller-driven cancellation can propagate to the
transport layer or hosting code.
Examples
routerBuilder.AddHandler("GET", "/api/users/{user_id:int}/*", (requestContext, callNext) =>
{
requestContext.Parameters["User"] = LoadUser((int) requestContext.Parameters["user_id"]!);
return callNext();
});