How to seed NetTopologySuite.Geometries.Point data from a Json file in ASP.Net core

Question

I want to seed "Location" data for my user object from my seed file

The c# object, where Point is a NetTopologySuite.Geometries.Point is part of my user object

  public class User: IdentityUser<int> {
      // member data here
      public Point Location { get; set; } // has lat/lng data points
  }

I seed data to my db on startup by doing something like this

public void SeedUsers()
{
    if (!_userManager.Users.Any())
    {
        var userData = System.IO.File.ReadAllText("Data/UserSeedData.json");
        var users = JsonConvert.DeserializeObject<List<User>>(userData);

        var roles = new List<Role>
        {
            new Role{Name = "Member"},
            new Role{Name = "Admin"},
            new Role{Name = "Moderator"},
            new Role{Name = "VIP"},
        };

        foreach (var role in roles)
        {
            _roleManager.CreateAsync(role).Wait();
        }

        foreach (var user in users)
        {
            user.Photos.SingleOrDefault().IsApproved = true;
            _userManager.CreateAsync(user, "password").Wait();
            _userManager.AddToRoleAsync(user, "Member").Wait();
        }
     }
 }

with a json file "UserSeedData.json" of json arrays like this and I want to be able to stick some kind of 'Location' data in there that is representative of lng/lat data points.

{
  "Email": "myemailaddress@gmail.com",
  "Username": "Lola",
  "Gender": "female",
  "DateOfBirth": "1994-02-21",
  "Password": "password",
  "Created": "2017-08-02",
  "LastActive": "2017-08-02",
  "Introduction": "blah blah blah",
  "LookingFor": "blah blah blah",
  "City": "San Francisco",
  "Country": "United States",
  "Longitude": -122.431297,
  "Latitude": 37.773972,
  "Location": // something here!!!
  "Photos": [{
    "url": "https://randomuser.me/api/portraits/women/3.jpg",
    "isMain": true,
    "description": "Non deserunt labore sunt ex laboris et adipisicing ullamco officia minim."
  }]
}

Now I know in my seed method I could do something like this, but I'm looking for a way to include it in my .json file, so I can use different data points

foreach (var user in users)
{
    user.Photos.SingleOrDefault().IsApproved = true;
    user.Location = new Point(-122.4194155, 37.7749295) { SRID = 4326 };
    _userManager.CreateAsync(user, "password").Wait();
    _userManager.AddToRoleAsync(user, "Member").Wait();
}

Answer 1

You could subclass NetTopologySuite.Geometries.Point and add a [JsonConstructor] to parse your json file. It should be a straightforward substitution for the rest of your code.

public class MyPoint : Point
{
    [JsonConstructor]
    public MyPoint(double latitude, double longitude, int srid)
        :base(new GeoAPI.Geometries.Coordinate(longitude, latitude))
    {
        SRID = srid;
    }
}

Note that latitude = y and longitude = x so the order is reversed.

Swap MyPoint for Point in your User class

public class User: IdentityUser<int> {
  // member data here
  public MyPoint Location { get; set; }
}

And it should work with your json as is.