Converting Dictionary with tuple and enum to JSON

Question

In my class, I have an enum definition as followed:

public enum ChangeType { 
  [EnumMember(Value ="Added")]
  Added,
  [EnumMember(Value = "Removed")]
  Removed,
  [EnumMember(Value = "Updated")]
  Updated 
}

And in the class definition, I have a property:

public 
  Dictionary<string, (ChangeType changType, string oldValue, string newValue)> 
  PropertyChanges { get; set; }

Requirements:

1. When converting to JSON, changeType should be in text, not number
2. Tuple should be converted w/ the name of the items instead of Item1, Item2 and Item3

What I have tried:

• As for the enum, I tried putting the JsonConverter(typeof(StringEnumConverter))] in front of the property (no go)
• Cannot any recommendation about the named tuples

Question:

Can I achieve the above without writing a custom converter to convert the whole class?

Thanks!

Answer 1

The names of ValueTuple keys basically don't exist after compilation, except for in some attributes, so the type info that the serializer gets doesn't contain the names.

So you'll have to use a class to control the serialized names, instead of that ValueTuple.

Answer 2

It's actually not as bad as I thought... JsonConvert.SerializeObject() already has already done a pretty good job serializing the Dictionary<>, so all I have to do is to help Json to interpret the enum and the tuple.

First, I create a class called CustomTupleConverter that implements JsonConverter<(ChangeType changeType, string oldValue, string newValue)>.

In the implementation of WriteJson(), I have the following:

writer.WriteStartObject();
writer.WritePropertyName("Action");
writer.WriteValue(value.changeType.ToString());
writer.WritePropertyName("OldValue");
writer.WriteValue(value.oldValue.ToString());
writer.WritePropertyName("NewValue");
writer.WriteValue(value.newValue.ToString());
writer.WriteEndObject();

When invoking the JsonConvert.SerializeObject(), I simply add the instantiation of my converter to the call:

JsonConvert.SerializeObject(cc, Formatting.Indented, new CustomTupleConverter());

That's it.