Nullable member of Record about delphi-neon

[paolo-rossi]

Hello @AlexeyM123 ,

to serialize this type you can use this code:

  var rec: TMyRecord;
  var res := TNeon.ValueToJSONString(TValue.From<TMyRecord>(rec), config);

and to deserialize the JSON string into a variable rec:

  var rec := TNeon.JSONToValue<TMyRecord>(GetJson, config);

I hope that this helps you, I'm closing the issue but feel free to ask again.

Paolo.

[AlexeyM123]

Dear Paolo.
Thank you for your lib and your assistance.
I will try to test the solution.

[AlexeyM123]

Dear Paolo
I tried TNeon.ValueToJSONString(TValue.From(rec))
A value of the nullable record member is omitted in JSON.

[paolo-rossi]

Alexey,

strange, I'm testing right now and the value of the field "Three" gets serialized (if it's not null)

I attach my test project (please rename it in TestIssue_88.dpr)
TestIssue_88.txt

Paolo.

[AlexeyM123]

Dear Paolo
Maybe I misunderstand the issue.
I expect if nullable value is null the json will be
{
"Three": null
}

[paolo-rossi]

Hello Alexey,

Ok now I see...

I will give you the explanation and a simple workaround, but I'm thinking to change that in a next release:

[Explanation]
The problem lies in the definition of the IncludeIf enum (Neon.Core.Attributes.pas line 92), as you can see the first enum (the default) is NotNull so all the properties/fields have a default of NotNull when serializing/deserializing meaning that Neon will skip that property/field if nil.

Now, it's probably better to have Always as default for props/fields but this will be a breaking change although I'm surely evaluating the change..

[Workaround]
Please annotate the Three property with IncludeIf.Always like that:

[NeonInclude(IncludeIf.Always)]
Three: Nullable<integer>;

If and when I change the default then you can remove the attribute (but in your case it doesn't change the result)

Ciao,
Paolo.

[AlexeyM123]

Dear Paolo
Thank you. Very appreciated