Hi. I'm trying to return content based on (optiona...

# http4k

[David Hamilton]

Hi. I'm trying to return content based on (optional) Accept header provided by client, providing json content only when specifically requested by the client.
However both my routes are now returning 405 whereas the fallback handler worked fine without the nested route:

"/mappings" bind routes(
                Method.GET to routes(
                    header("Accept", "application/json") bind ingressTracingLoggingFilter.then(mappingsAdminJsonHandler),
                    Fallback bind ingressTracingLoggingFilter.then(mappingsAdminReportHandler)
                ),
                <http://Method.POST|Method.POST> to someOtherHandler
            ),

What am I doing wrong?

[dave]

first question - are you sure that the content type being sent hasn't got the charset on it? can you debug and show the request being sent?

[David Hamilton]

The test uses http to make the call, e.g.:

Request(Method.GET, "<http://localhost>:$servicePort$path")
    .header("Accept", "application/json")
    .execute()

So surely that would match the filter? Also, why 405? Surely it should be handled by the Fallback section? And why has the non-JSON test, which should be handled by the Fallback anyway suddenly started failing with 405 responses?
I'll investigate further this morning

[David Hamilton]

I completely get your point about charsets through.
Is there a better/canonical way of doing accept header checking / content negotiation?

[David Hamilton]

To clarify my original message, this GET routing (without the accept filter) used to work in the test for non-JSON content:

"/mappings" bind routes(
                Method.GET to  ingressTracingLoggingFilter.then(mappingsAdminReportHandler),
                <http://Method.POST|Method.POST> to someOtherHandler
            ),

But now that non-JSON test also fails with 405 response

[David Hamilton]

Update: Separating completely the routes for the differing Accept rules works (passes the test case) with no further changes:

"/mappings" bind routes(
    Method.GET.and(header("Accept", "application/json")) bind ingressTracingLoggingFilter.then(mappingsAdminJsonHandler),
),
"/mappings" bind routes(
    Method.GET to ingressTracingLoggingFilter.then(mappingsAdminReportHandler),
),

So why does that work, and not the nested header filter and fallback?

[dave]

405 normally occurs when we match the route but not the verb.
. Could you put a quick gist together with a runnable example - as there's a lot of detail here that am probably missing

[dave]

Your content negotiation approach is fine btw

[David Hamilton]

Sure, I'll work up a simple example 👍