Avoid serialization of empty field

[KonradEichstaedt]

Hi Kevin,

I need to create an IIIF-Manifest Version 3.0 and used your API. The JSON Result shows always empty fields like this:

placeholderCanvas : {"empty" : true,"present" : false }

I used the default ObjectMaper of Jackson to write the JSON String.

How can I avoid this serialization of the empty fields?

Many Thanks,

Konrad

[ksclarke]

Oops, sorry, just seeing this now @KonradEichstaedt (I have fallen behind in my inbox/alerts).

This is probably because the internal (de)serializer has values set that you're not setting on your ObjectMapper:

jiiify-presentation/src/main/java/info/freelibrary/iiif/presentation/v3/utils/JSON.java

Lines 33 to 37 in 786d782

	private static final ObjectMapper MAPPER = new ObjectMapper().configure(SerializationFeature.INDENT_OUTPUT, true)
	.configure(DeserializationFeature.ACCEPT_EMPTY_ARRAY_AS_NULL_OBJECT, true)
	.configure(DeserializationFeature.ACCEPT_EMPTY_STRING_AS_NULL_OBJECT, true)
	.registerModules(new Jdk8Module().configureAbsentsAsNulls(true),
	new SimpleModule().addSerializer(float.class, new JSON().new FloatSerializer()));

Just to turn the Manifest into a String, though, you should be able to use the Manifest's toString() method (and that should use the internal mapper). The string representation that's output is JSON.

If this isn't the case for you, could you give me a little reproduceable code snippet to show the issue? Thanks!

[ksclarke]

Just to make the connection between related issues, someone else is seeing this problem too: #174 -- Looking for a test case so I can understand how it's being serialized without the JSON util.

[ksclarke]

Version 0.12.3 should fix this without adding the additional module.