Nullable DateTime in Dictionary can't use custom converter to convert into empty string

[kamyaw010]

Nullable DateTime in Dictionary can't use custom converter to convert into empty string

[elgonzo]

The behavior you see is pretty much hard-coded:

Newtonsoft.Json/Src/Newtonsoft.Json/Serialization/JsonSerializerInternalWriter.cs

Lines 154 to 160 in 2eaa475

	private void SerializeValue(JsonWriter writer, object? value, JsonContract? valueContract, JsonProperty? member, JsonContainerContract? containerContract, JsonProperty? containerProperty)
	{
	if (value == null)
	{
	writer.WriteNull();
	return;
	}

As a (past) user of the library myself (only still using it in old legacy projects i didn't migrate to modern .NET), i have to admit that i can't muster much hope for this situation to be improved. That said, feel free to look at Newtonsoft.Json's development activities over the last few years and form your own opinion about it.

A work-around for this limitation is to write a converter that deals with the dictionary itself -- this way, this dictionary converter would then be able to iterate over the dictionary, deal with Nullable<T> values itself directly (thus bypassing hard-coded null checks in the serializer) and write/serialize the dictionary data to the JsonWriter in whatever way you need. If you feel this being too much work or your real situation is more complex and involving not just dictionaries with values from a limited number of relatively simple types, i would strongly suggest you contemplate switching to STJ if there are no roadblocks preventing you from doing that...

[kamyaw010]

The behavior you see is pretty much hard-coded:

Newtonsoft.Json/Src/Newtonsoft.Json/Serialization/JsonSerializerInternalWriter.cs

Lines 154 to 160 in 2eaa475

	private void SerializeValue(JsonWriter writer, object? value, JsonContract? valueContract, JsonProperty? member, JsonContainerContract? containerContract, JsonProperty? containerProperty)
	{
	if (value == null)
	{
	writer.WriteNull();
	return;
	}

As a (past) user of the library myself (only still using it in old legacy projects i didn't migrate to modern .NET), i have to admit that i can't muster much hope for this situation to be improved. That said, feel free to look at Newtonsoft.Json's development activities over the last few years and form your own opinion about it.

A work-around for this limitation is to write a converter that deals with the dictionary itself -- this way, this dictionary converter would then be able to iterate over the dictionary, deal with Nullable values itself directly (thus bypassing hard-coded null checks in the serializer) and write/serialize the dictionary data to the JsonWriter in whatever way you need. If you feel this being too much work or your real situation is more complex and involving not just simple dictionaries, i would strongly suggest you contemplate switching to STJ if there are no roadblocks preventing you from doing that...

For some reasons, can't switch back to STJ :(
Seems can just hold a converter for the dictionary otherwise change this field into string? and handle it myself
Thanks.

[elgonzo]

For some reasons, can't switch back to STJ :(

That's unfortunate :-( because this would be easy-peasy to do in STJ https://dotnetfiddle.net/RDmNxD