null values are stripped when serializing

[larssn]

Hello, thanks for a wonderful plugin. It's making our boilerplate related headacres go away.

However we're running into a minor issue serializing data into a Firestore compatible Map. The generated serializers are stripping out nulls (which makes sense in a JSON context).

The offending code is the if that is generated in the .g.dart files, for example:

if (object.color != null) {
      result
        ..add('color')
        ..add(serializers.serialize(object.color,
            specifiedType: const FullType(String)));
}

If we comment it out, our resulting Map has keys with nulls, as desired.

Any way to make built_value not generate that if check?

[davidmorgan]

Not currently.

We could potentially add it as a configuration setting on the serializer field.

@BuiltValueSerializer(includeNulls: true)

From your side, you could post-process the data to add in the nulls, but that's a bit awkward unless you have the list of keys / field names handy.

[larssn]

Well it's a bit of a pain point currently. We're probably gonna lean on post-processing, since it's cleaner than setting a string to '', an array to [], a number to 0 (iffy), etc.

Your suggested solution seems like a good, clean idea though.

[larssn]

@davidmorgan This feature was stripped from v8 correct? If so, how to handle it? Our requirements remain the same: It is useful to serialize nulls when working with Firestore.

[davidmorgan]

Yes--but it looks like I could actually add it back--will aim to do so.

[kuhnroyal]

With a global option and a per-field override? #912
I would love to not have to write custom serializers for that :)

[larssn]

Any workaround until this gets implemented? We have a ton of code that relies on this, from the old version. There's currently a lot of glitches related to saving data, which is to be expected, but not optimal. 😅

[kuhnroyal]

The serializer class can handle null now but all the default serializers don't serialize null.
I am currently writing the serializer manually where this is needed but that is not ideal.

[larssn]

@davidmorgan Will you accept a PR that re-implements this? I assume the solution is similar to the last one?

[larssn]

@kuhnroyal Thanks for the suggestion but we have more than 100 built value entities, so writing a custom serializer for most of them is probably gonna take longer than a PR. 😊

[kuhnroyal]

@larssn I agree. I implemented this in the OpenAPI generator by generating it from a mustache template: https://github.com/OpenAPITools/openapi-generator/blob/master/modules/openapi-generator/src/main/resources/dart/libraries/dio/serialization/built_value/class.mustache#L58

I would also love to have something like @BuiltValueField(serializeNull: true) so I can set this per field and not only global.
See #912

[larssn]

@kuhnroyal My first priority is just to get it back to how it was. A BuiltValueField has to come later. We have a deadline next monday, and this is a blocker.

[davidmorgan]

#1049