Hi - is there a way to override the body lens serialisation setting to not write empty lists as null...

# http4k

[Volkan Nezir]

Hi - is there a way to override the body lens serialisation setting to not write empty lists as nulls? Nulls.AS_EMPTY

[dave]

you can define your own Jackson object using the template here:

object Jackson : ConfigurableJackson(KotlinModule()
    .asConfigurable()
    .withStandardMappings()
    .done()
    .disableDefaultTyping()
    .configure(FAIL_ON_UNKNOWN_PROPERTIES, false)
    .configure(FAIL_ON_IGNORED_PROPERTIES, false)
    .configure(USE_BIG_DECIMAL_FOR_FLOATS, true)
    .configure(USE_BIG_INTEGER_FOR_INTS, true)
)

[dave]

(the last lines there are the Jackson mapper config)

[dave]

(assuming Jackson)

[Volkan Nezir]

yes correct - thank you. so if I include this definition, is this automatically picked up by http4k?

[dave]

no - when you define your own Jackson instance you will need to import everything from there instead of from our Jackson

[dave]

object MyJackson : ConfigurableJackson(KotlinModule()
    .asConfigurable()
    .withStandardMappings()
    .done()
    .disableDefaultTyping()
    .configure(FAIL_ON_UNKNOWN_PROPERTIES, false)
    .configure(FAIL_ON_IGNORED_PROPERTIES, false)
    .configure(USE_BIG_DECIMAL_FOR_FLOATS, true)
    .configure(USE_BIG_INTEGER_FOR_INTS, true)
)

[dave]

then import org.bob.MyJackson.auto

[Volkan Nezir]

oh I see ok - thanks!