ASP.NET json object doesn't contain custom object - asp.net

Question

When a user gets to a location, he will get a question. As such, I have a class for "Questions" and a class for "Locations". When I retrieve a location, however, the Question parameter is always null.
This seems to be a problem with the whole project, as the same problem repeats itself somewhere else (here, a "Game" has a list of "Teams", but the teams are always empty).
Objects are created when database is initialized:
public static void Initialize(DBContext context)
{
context.Database.EnsureCreated();
if (!context.Games.Any())
{
var teams = new List<Team>();
var team1 = new Team()
{
TeamName = "Kwizmasterz",
TotalPoints = 0,
TotalBoobyTraps = 2
};
var team2 = new Team()
{
TeamName = "Xesennettet",
TotalPoints = 0,
TotalBoobyTraps = 2
};
teams.Add(team1);
teams.Add(team2);
var game = new Game()
{
GameCode = "X35H0",
team = teams
};
context.Games.Add(game);
context.SaveChanges();
}
if (!context.Locations.Any())
{
var que = new Question()
{
QuestionText = "How much is 2 + 2?",
Answer = "4",
IsSolved = false,
Points = 1000000
};
var loc = new Location()
{
LocationName = "LocationName",
Latitude = 50.2299036,
Longitude = 5.4163052,
Question = que,
IsBoobyTrapped = false
};
context.Locations.Add(loc);
context.SaveChanges();
}
}
Location Class:
public class Location
{
public int LocationID { get; set; }
public string LocationName { get; set; }
public double Latitude { get; set; }
public double Longitude { get; set; }
public Question Question { get; set; }
public bool IsBoobyTrapped { get; set; }
public int VictorTeamID { get; set; } = -1;
}
Question Class:
public class Question
{
public int QuestionID { get; set; }
public int QuestionType { get; set; } // 1 = Question - Answer
public string QuestionText { get; set; }
public int Points { get; set; }
public bool IsSolved { get; set; }
public string Answer { get; set; }
}
Controller Class:
[Route("api/v1")]
public class GameController : Controller
{
private readonly DBContext context;
public GameController(DBContext context)
{
this.context = context;
}
public IActionResult Index()
{
return View();
}
[Route("location")]
[HttpPost]
public IActionResult postGame([FromBody] Location newLocation)
{
newLocation.LocationID = context.Games.Count();
context.Locations.Add(newLocation);
return Created("", newLocation);
}
[Route("location")]
[HttpGet]
public List<Location> getLocations()
{
return context.Locations.ToList();
}
[Route("location/{id}")]
[HttpGet]
public Location getLocation(int id)
{
int _id = id - 1;
List<Location> loc = context.Locations.ToList();
if (loc[_id] != null)
return loc[_id];
else
return null;
}
[Route("game")]
[HttpPost]
public IActionResult postGame([FromBody] Game newGame)
{
newGame.GameID = context.Games.Count();
context.Games.Add(newGame);
return Created("", newGame);
}
[Route("game")]
[HttpGet]
public List<Game> getGames()
{
return context.Games.ToList();
}
[Route("game/{id}")]
[HttpGet]
public Game getGame(int id)
{
List<Game> game = context.Games.ToList();
if (game[id] != null)
return game[id];
else
return null;
}
}

Answer 1

This is because of lazy loading so objects stored in other tables won't load unless you include them.
Link
You can do this by using Include("Question") so the complete syntax would be:
context.Locations.Include("Question") so you will include the question when retrieving the locations
You can do also multiple includes by chaining them context.Locations.Include("Question").Include("SomethingElse")
Edit as i see in your code getLocation still does not use the include. see below for the correct way to use it
public Location getLocation(int id)
{
int _id = id - 1;
List<Location> loc = context.Locations.Include("Question").ToList();
if (loc[_id] != null)
return loc[_id];
else
return null;
}
2nd edit
Also i would rewrite getLocation because your pulling the whole list first and after getting the single location
public Location getLocation(int id)
{
int _id = id - 1;
//FirstOrDefault will return automatically a null if the id cannot be found.
//This will result in only getting the single Location from context instead the complete list
return context.Locations.Include("Question").FirstOrDefault(x=>x.id == _id);
}