<@UG2RK4C10> this is pretty standard Jackson behaviour - when in doubt it does deserialise using Map...

# http4k

[dave]

@Tom Ellis this is pretty standard Jackson behaviour - when in doubt it does deserialise using Maps (we see the same with generic lists). It's nothing to do with http4k per-se, but about how you set up the Jackson mapper instance and annotate the classes for deserialisation with something like @JsonTypeInfo. TBH, I generally try to make DTO objects as dumb as possible as I hate all the annotations.

[Tom Ellis]

hmm - the thing is if i just do this, it’s fine:

val jacksonResult = jacksonObjectMapper().readValue<Result<MyClass>>(response.bodyString())
println(jacksonResult.body.message)

so i have a workaround, it would just be nice to use the lens…

[dave]

Interesting - we're using convertValue instead of readValue. Not sure of the difference. Will have to investigate

[Riku]

I don't know if this is related at all but I also found cases when default mapper didn't work for mysterious reasons (or reasons I never looked into) but using our mapper always worked fine

[Riku]

val mapper = KotlinModule()
    .asConfigurable()
    .withStandardMappings()
    .done()
    .registerModule(JodaModule())
    .disableDefaultTyping()
    .configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false)
    .configure(DeserializationFeature.FAIL_ON_IGNORED_PROPERTIES, true)
    .configure(DeserializationFeature.USE_BIG_DECIMAL_FOR_FLOATS, true)
    .configure(DeserializationFeature.USE_BIG_INTEGER_FOR_INTS, true)
    .configure(com.fasterxml.jackson.databind.SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, true)

[Riku]

actually I now realize this is nothing to do with your case

[dave]

@Riku what types didn't work for you with the default version?

[Riku]

I can't remember off hand, there were two cases

[Riku]

data class EventInDto(
    val name: String,
    val sponsor: String,
    val contact: String,
    val date: Timestamp,
    val details: String,
    val location: String,
    val status: EventStatus = EventStatus.PLANNING,
    val maxParticipants: Int,
    val registrationOpens: Timestamp,
    val volume: Int,
    val sponsorLink: String
)`

[Riku]

that was one

[dave]

is that a SQL Timestamp?

[Riku]

yeah that is my blurry memory

[Riku]

might run it tonight when at home just to check

[dave]

cool we can probably add that to the standard mappings

[dave]

(let me know if we need to) 🙂

[Riku]

ah hey, we are using readValue now too

[Riku]

because we validate the json, we are doing Body.string(ContentType.APPLICATION_JSON).map { json -> EventInDto.from(json) }.toLens()

[Riku]

and inside from readValue

[Riku]

but then else where we do use the mapper directly in the lens

[Riku]

and I think there was another spot it also fixed an issue

[Riku]

I guess that use of the lens is kind of hacky

[dave]

i'll fix it up to use readValue and also to support Timestamp, then you can remove the hack!

[dave]

and in future, please let us know if you think you need to hack around stuff ... I am figuratively dying of professional embarrassment here 😉

[dave]

@Riku presumably timestamps are transmitted as longs over the wire - or strings?

[dave]

hmm - timestamp as a number actually seems a little dodgy. think we'll release with the other fix and look at timestamp later. 🙂

[Riku]

Ours are strings. now i wonder if we even typed them correctly 😆. Well if it aint broke...