Self referencing loop Entity FrameWork

Question

I'm currently using WebApi 2.0 and EntityFrameWork and I'm having issues with it:

Self referencing loop detected for property 'UserInfo' with type 'System.Data.Entity.DynamicProxies.UserInfo_F7C6DF3909A804C5A9AC107297C8851F4CC9DF1CCA4A689B892B6C6EBA5A6EA8'. Path '[0].User'."

my DB is something like this: User-UserInfo and is 1-1 relationship, the PK of User is the PF in UserInfo;

public class User {    
        public int UserId { set; get; }
        public string username { set; get; }
        public string password { set; get; }
        public string name { set; get; }
        public string email { set; get; }
        public string surname { set; get; }
        public string lastName { set; get; }
        public int age { set; get; }
        public DateTime regDate { set; get; }
        public bool userType { set; get; }

        //we define our relationships
        //1-1 UserModel-UserInfo
        public virtual UserInfo UserInfo { set; get; }
}

My UserInfo class:

public class UserInfo { 
    [Key, ForeignKey("User")]
    public int UserId { set; get; }        
    public string username { set; get; }        
    public string phone{ set; get; }        
    public string adress { set; get; }        
    public string country { set; get; }        
    public string city { set; get; }        
    public string zip { set; get; }

    //we define our relationships 
    //1-1 UserModel-UserInfo
    public virtual User User { set; get; }

}

In Postman I send a Post request and register a user:

{
  "username": "otmanlicona",
  "password": "pwd1234",
  "name": "Otman",
  "email": "otmanlicona17@mail.com",
  "surname": "licona",
  "lastName": "ledezma",
  "age": 33,
  "regDate": "2017-03-01T18:10:11+00:00",
  "userType": false
}

If I send a GET request I get all the users:

[
  {
    "Orders": [],
    "ReviewProducts": [],
    "UserInfo": null,
    "UserId": 7,
    "username": "otmanlicona",
    "password": "pwd1234",
    "name": "Otman",
    "email": "otmanlicona17@mail.com",
    "surname": "licona",
    "lastName": "ledezma",
    "age": 33,
    "regDate": "2017-03-01T12:10:11",
    "userType": false
  },
  {
    "Orders": [],
    "ReviewProducts": [],
    "UserInfo": null,
    "UserId": 8,
    "username": "angelsilva",
    "password": "pwd1234",
    "name": "angel",
    "email": "angelsilva@mail.com",
    "surname": "silva",
    "lastName": "borja",
    "age": 22,
    "regDate": "2017-03-01T12:10:11",
    "userType": true
  }
]

No problems so far , the problem is when I insert the UserInfo:

{
  "UserId": 8,
  "username": "angelsilva",
  "phone": "12345678",
  "adress": "550 Swallow Hill",
  "country": "USA",
  "city": "foo",
  "zip": "47-253"
}

If I send another GET request I get an Exception: Image of the error

Self referencing loop detected for property 'UserInfo'

Can anyone tell me what I'm doing wrong?,Thanks

[
  {
    "Orders": [],
    "ReviewProducts": [],
    "UserInfo": null,
    "UserId": 7,
    "username": "otmanlicona",
    "password": "pwd1234",
    "name": "Otman",
    "email": "otmanlicona17@mail.com",
    "surname": "licona",
    "lastName": "ledezma",
    "age": 33,
    "regDate": "2017-03-01T12:10:11",
    "userType": false
  },
  {
    "Orders": [],
    "ReviewProducts": [],
    "UserInfo": {
      "UserId": 8,
      "username": "angelsilva",
      "phone": "12345678",
      "adress": "550 Swallow Hill",
      "country": "USA",
      "city": "foo",
      "zip": "47-253"
    },
    "UserId": 8,
    "username": "angelsilva",
    "password": "pwd1234",
    "name": "angel",
    "email": "angelsilva@mail.com",
    "surname": "silva",
    "lastName": "borja",
    "age": 22,
    "regDate": "2017-03-01T12:10:11",
    "userType": true
  }
]

NOW I see what does Entity Framework meant by self referencing loop; What can I do so in my Get response only returns me the other values that aren't in the User Class like username,phone,address,country, etc.

Answer 1

try this on startup .cs 

 config.Formatters.JsonFormatter.SerializerSettings.ReferenceLoopHandling 
= Newtonsoft.Json.ReferenceLoopHandling.Ignore;