What's the propper way to handle enum flags?

[paulomorgado]

What I expect/want is for this:

[Flags]
public enum Directions
{
    Up = 1,
    Down = 2,
    Left = 4,
    Right = 8,
}

public class Request
{
    Directions Directions {get; set; }
}

public void SetAvailableDirections(Request request)
{
    // ...
}

To generate a swagger specification where the Directions property allows multiple values (array with collectionFormat set to csv ???) but not needing the Directions property to be an array.

JsonConvert.SerializeObject(Directions.Up | Directions.Right, new StringEnumConverter(true)) already outputs the correct value: "up, right"

I tried to generate a client from this swagger:

{
  "consumes": [
    "application/json"
  ],
  "produces": [
    "application/json"
  ],
  "paths": {
    "/api/SetAvailableDirections": {
      "post": {
        "operationId": "SetAvailableDirections",
        "parameters": [
          {
            "name": "request",
            "in": "body",
            "schema": {
              "$ref": "#/definitions/Request"
            },
            "x-nullable": true
          }
        ],
        "responses": {
          "200": {
            "description": ""
          }
        }
      }
    },
  },
  "definitions": {
    "Request": {
      "type": "object",
      "additionalProperties": false,
      "properties": {
        "Directions": {
          "type": "array",
          "items": {
            "$ref": "#/definitions/Directions"
          },
          "collectionFormat": "csv"
        }
      }
    },
    "Directions" : {
      "type": "string",
      "x-enumNames": [
        "Up",
        "Down",
        "Left",
        "Right"
      ],
      "enum": [
        "Up",
        "Down",
        "Left",
        "Right"
      ],
      "description": ""
    }
  },
  "parameters": {},
  "responses": {},
}

and it generates this:

[System.CodeDom.Compiler.GeneratedCode("NJsonSchema", "8.8.6270.12833")]
public partial class Request 
{
    [Newtonsoft.Json.JsonProperty("Directions", Required = Newtonsoft.Json.Required.Default, NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore, ItemConverterType = typeof(Newtonsoft.Json.Converters.StringEnumConverter))]
    public System.Collections.Generic.List<Directions> Directions { get; set; }

    public string ToJson() 
    {
        return Newtonsoft.Json.JsonConvert.SerializeObject(this);
    }
    
    public static Request FromJson(string data)
    {
        return Newtonsoft.Json.JsonConvert.DeserializeObject<Request>(data);
    }
}

[System.CodeDom.Compiler.GeneratedCode("NJsonSchema", "8.8.6270.12833")]
public enum Directions
{
    [System.Runtime.Serialization.EnumMember(Value = "Up")]
    Up = 0,

    [System.Runtime.Serialization.EnumMember(Value = "Down")]
    Down = 1,

    [System.Runtime.Serialization.EnumMember(Value = "Left")]
    Left = 2,

    [System.Runtime.Serialization.EnumMember(Value = "Right")]
    Right = 3,

}

which I don't think complies to the swagger specification because this:

sonConvert.SerializeObject(new Request { Directions = new List<Directions> { Directions.Up, Directions.Right } }, new StringEnumConverter(true))

yields this:

{"Directions":["Up","Right"]}

If I change the code to:

public partial class Request
{
    [Newtonsoft.Json.JsonProperty("Directions", Required = Newtonsoft.Json.Required.Default, NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore, ItemConverterType = typeof(Newtonsoft.Json.Converters.StringEnumConverter))]
    public Directions Directions { get; set; }

    public string ToJson()
    {
        return Newtonsoft.Json.JsonConvert.SerializeObject(this);
    }

    public static Request FromJson(string data)
    {
        return Newtonsoft.Json.JsonConvert.DeserializeObject<Request>(data);
    }
}

[Flags]
public enum Directions
{
    [System.Runtime.Serialization.EnumMember(Value = "Up")]
    Up = 1,

    [System.Runtime.Serialization.EnumMember(Value = "Down")]
    Down = 2,

    [System.Runtime.Serialization.EnumMember(Value = "Left")]
    Left = 4,

    [System.Runtime.Serialization.EnumMember(Value = "Right")]
    Right = 8,
}

for this:

JsonConvert.SerializeObject(new Request { Directions = Directions.Up | Directions.Right }, new StringEnumConverter(true))

I get this:

{"Directions":"up, right"}

Which is what I was expecting from that swagger.

[RicoSuter]

See RicoSuter/NJsonSchema#226