Using JsonProperty for Deserializing but NOT serializing

Question

I have a backend-service that calls a REST-Api. The result of that API is then deserialized into my entity:

public class Item {
  [JsonProperty("pkID")]
  public int Id {get;set;}
}

JsonConvert.DeserializeObject<Item>(responseString);

This works fine. But I also want to return the result as a JSON-string so I can use it from the Frontend. When now Serializing my object of Type "Item" using JsonConvert.SerializeObject(item) I want to return something like

{ Id: 1 }

Instead on serializing it also uses the JsonProperty and returns

{ pkID: 1 }

instead.

How can I tell the serializer to ignore the JsonProperty on serializing, but use it on deserializing?

I am NOT searching for a way whether the property should be serialized or not, but whether the propertyName should be used or the the name from the JsonProperty on serializing.

In the question you linked it was about not serializing the property at all. I am asking for a way to keep the PropertyName instead — Ole Albers, Aug 27 '19 at 09:37
@OleAlbers there is a pointer to `IContractResolver` which can help you to do this strange things that you are doing — vasily.sib, Aug 27 '19 at 09:42
@vasily.sib I followed the description and AFAIK (I might be wrong here) it looks like this is about Serializing or not serializing the property and NOT what name the property should have. — Ole Albers, Aug 27 '19 at 09:47
2 more things to try: 1 - make your frontend to work with `pkID` instead of `Id`. 2 - create another class of your `Item` just for your frontend. — vasily.sib, Aug 27 '19 at 09:51

sa.he · Accepted Answer · 2019-08-27T11:08:37.320

4

You could use a set-only property that points to the 'good' property.

public class Item
{
    public int Id { get; set; }

    [JsonProperty("pkID")]
    public int BackwardCompatibleId { set => Id = value; }
}

// test
var x = new Item { Id = 88 };
var json = JsonConvert.SerializeObject(x); // {"Id":88}
var clone = JsonConvert.DeserializeObject<Item>("{\"pkId\":99}");

edited Aug 27 '19 at 11:08

answered Aug 27 '19 at 09:51

sa.he

1,391
12
25

While this does work the main reason I want to do this is to have "clean" code with Pascal-Casing as it should be and not having the REST-Interface forcing me to use "bad" naming – Ole Albers Aug 27 '19 at 10:10
1

Good point. I updated the answer using JsonPropertyAttribute as you did in the question. You could also try making 'BackwardCompatibleId' private to hide this 'hack' from other classes. – sa.he Aug 27 '19 at 11:10

score 1 · Answer 2 · answered Aug 27 '19 at 10:02

1

you could use an own implementation of the ContractResolver.

here is an answer that could probably work: https://stackoverflow.com/a/20639697/5018895

answered Aug 27 '19 at 10:02

CodeMonkey1770

94
4

Thx. THAT really was a duplicate from my question – Ole Albers Aug 27 '19 at 10:14

Using JsonProperty for Deserializing but NOT serializing

2 Answers2