Entity - Infinite loop in JSON conversion

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What happens

I’m having a problem using Entity with my application MVC. What happens is that when converting a class to JSON the program enters an infinite loop and ends up returning no-content

Example

Taking the relationship as an example (1-n):

A Autor has several Posts.

What I realized by debugging is that with a JSON the following interpretation will occur:

An author has several posts. A post has an author. An author has several posts. A post has an author...

Of course that’s not really my class situation, but what happens is the same idea. When I go to see in my API the answer is no-content. When I insert [JsonIgnore] in my properties that is adjusted, but then I lose one side of the relationship, which is a price I cannot pay for the operation of the application.

I would like to know how to proceed and do the Entity do not enter this infinite loop.

EDITION: Code

Models

Team.Cs

public class Team : TEntity
{
  public int ID {get; set;}

  public string Function {get; set;}

  public int LeaderID {get; set;}

  public User Leader {get; set;}

  public List<TeamUser> Users {get; set;}
}

Teamuser.Cs

public class TeamUser : TEntity
{
  public int ID {get; set;}

  public int TeamID { get; set; }

  public int UserID { get; set; }

  //Aqui, sem essa anotação já retornaria "no-content" (acredito eu, devido ao bug do loop)
  [JsonIgnore]
  public virtual Team Team { get; set; }

  public virtual User User { get; set; }
}

User.Cs

public class User : TEntity
{
  public int ID {get; set;}

  ...

  // o mesmo aqui
  [JsonIgnore]
  public virtual IList<TeamUser> Teams {get; set;}

  // e aqui
  [JsonIgnore]
  public virtual IList<Team> TeamsLeadered {get; set;}

Entity Configuration Files

Teamconfiguration.Cs

...
builder
  .Property(t => t.LeaderID)
  .HasColumnName("ID_LIDER");

builder
  .HasOne(t => t.Leader)
  .WithMany(u => u.LeaderedTeams)
  .HasForeignKey(t => t.LeaderID);

Teamuserconfiguration.Cs

builder
  .Property(tu => tu.TeamID)
  .HasColumnName("ID_EQUIPE");

builder
  .Property(tu => tu.UserID)
  .HasColumnName("ID_USUARIO");

builder
  .HasOne(tu => tu.Team)
  .WithMany(t => t.Users)
  .HasForeignKey(tu => tu.TeamID);

builder
  .HasOne(tu => tu.User)
  .WithMany(u => u.Teams)
  .HasForeignKey(tu => tu.UserID);

Getall()

public IEnumerable<Team> GetAll()
{

    var teams = _context.Teams
       .Include(t => t.Leader)
       .Include(t => t.Users)
       //Aqui eu precisaria de um ThenInclude(t => t.User) mas retorna no-content
       .ToList();

    return teams;
 }
c# json entity-framework api

  • Post the code you’re using for such a buddy routine

  • Add your code so we can help you.

  • Edited question, with code added. There I explain that, the way it is, it works, but to do a search of users of a Team for example, I can no longer.

  • How you are converting your object to JSON?

1 answer

0

When serializing your object add the property JsonSerializerSettings and configure to ignore loops when doing serialization.

If you are using the Newtonsoft.Json to carry out serialization would be as follows:

JsonConvert.SerializeObject(objeto1, Formatting.Indented, new JsonSerializerSettings
{
    ReferenceLoopHandling = ReferenceLoopHandling.Ignore
});

If you are using ASP.NET Core Web Api, in your Webapiconfig.Cs add this setting:

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

ASP.NET Core reference: https://code.msdn.microsoft.com/Loop-Reference-handling-in-caaffaf7

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