.NET Core 3.0 WebApi (JsonSerialize) Does not Serialize Nested Objects/All object information

Question

I have a list of object as IEnumerable<IHit<Header>>, but .NET Core 3.0 is not emitting all information

this is when I return a single object IHit of the list obj.ElementAt(0)

{"explanation":null,"fields":null,"highlight":{},"id":"123","index":"ky","innerHits":{},"matchedQueries":[],"nested":null, "primaryTerm":null, "routing":null, "score":10.98915, "sequenceNumber":null, "sorts":[],"source":{"timeStamp":"2019-05-16T06:16:07Z", "result":"PASS","testTimeStart":"20190516141559","testTimeEnd":"20190516141607","barcode":"XXRX8762"},"type":"_doc","version":0}

but when I return the list itself:

[{"explanation":null,"fields":null,"highlight":{},"innerHits":{},"matchedQueries":[],"nested":null,"score":10.98915,"sorts":[]}]

also when I try explicitly to call JsonSerializer

string s = JsonSerializer.Serialize(result, typeof(IEnumerable<IHit<Header>>), obj);

To Wrap Up:

1. WebApi is working correctly and returning the object serialized correctly if a signle object:

   public IHit<Header> Get(string id)

but when a list, then it is not.

public IEnumerable<IHit<Header>> GetAll()

I tried IEnumerable, IList, List and all the same result!

2. JsonSerializer is working neither with a single object nor with a list

Answer 1

I still don't know the weird behavior I faced due to emitting a single object while not the case of list.

but here how solved the problem based on @poke's answer and @NeilMacMullen's comment

1. add package Microsoft.AspNetCore.Mvc.NewtonsoftJson

2. in Startup.cs, add

   services.AddControllers().AddNewtonsoftJson();

Answer 2

Add the attribute [JsonInclude] with .Net 6 for it to serialize lists

e.g.

   [JsonInclude]
   public List<StaffEarningDetail> EarningDetails;

Answer 3

If your are using Newtonsoft.Json then do as follows:

public void ConfigureServices(IServiceCollection services)
{
    ...

    services.AddMvc()
        .AddJsonOptions(
            options => options.SerializerSettings.ReferenceLoopHandling = Newtonsoft.Json.ReferenceLoopHandling.Ignore;
        );

    ...
}

If you are not using Newtonsoft.Json then do as follows:

public void ConfigureServices(IServiceCollection services)
{
    ...

   services.AddMvc().AddJsonOptions(option => option.JsonSerializerOptions.MaxDepth = 2);

    ...
}

For more details : Related data and serializatione

Answer 4

JsonSerializer likely does not know how to serialize IHit<T>. I would propose one of:

Getting the JSON string response from Elasticsearch, using either

1. the low level client, exposed on the high level client as the .LowLevel property. You can serialize a high level request type using PostData.Serializable(request)
2. using OnRequestCompleted() and setting DisableDirectStreaming() on the request or globally on ConnectionSettings

or

Mapping the response from Elasticsearch to another type that JsonSerializer will serialize.

Answer 5

In my case I've mistakenly written internal set function at ViewModel class properties as follows;

public int CampaignServiceFee { get; internal set; }

just removed the internal keyword so that outside of class, JsonSerializer, can set values.