Reputation: 97
I will try to explain my problem as thoroughly as possible with a simplified example. Please note that I am NOT using Entity Framework.
I have this model:
public class Person
{
[Key]
public Guid Id { get; set; }
public string GivenName { get; set; }
public string FamilyName { get; set; }
public List<Employment> Employments { get; set; }
}
public class Employment
{
public string Role { get; set; }
public Guid? ManagerId { get; set; }
public virtual Person Manager { get; set; }
}
I create an in-memory data source:
public class MyDataSource
{
private static MyDataSource instance = null;
public static MyDataSource Instance
{
get
{
if (instance == null)
{
instance = new MyDataSource();
}
return instance;
}
}
public List<Person> Persons { get; set; }
private MyDataSource()
{
this.Persons = new List<Person>();
this.Persons.AddRange(new List<Person>
{
new Person()
{
Id = Guid.Parse("00000000-0000-0000-0000-000000000001"), //Just for simplicity
GivenName = "John",
FamilyName = "Doe",
Employments = new List<Employment>()
{
new Employment()
{
Role = "Boss"
}
}
},
new Person()
{
Id = Guid.Parse("00000000-0000-0000-0000-000000000002"), //Just for simplicity
GivenName = "Clark",
FamilyName = "Kent",
Employments = new List<Employment>()
{
new Employment()
{
Role = "Worker",
ManagerId = Guid.Parse("00000000-0000-0000-0000-000000000001"), //Just for simplicity
}
}
}
});
}
}
I have this controller:
[EnableQuery]
public class PersonsController : ODataController
{
public IHttpActionResult Get()
{
return Ok(MyDataSource.Instance.Persons)
}
}
I configure the EndPoint:
public static class WebApiConfig
{
public static void Register(HttpConfiguration config)
{
config.MapODataServiceRoute("ODataRoute", "odata", CreateEdmModel());
config.Select().Expand().Filter().OrderBy().MaxTop(null).Count()
}
public static IEdmModel CreateEdmModel()
{
var builder = new ODataConventionModelBuilder();
var persons = builder.EntitySet<Person>("Persons");
builder.ComplexType<Employment>().HasOptional(e => e.Manager, (e, p) => e.ManagerId == p.Id);
return builder.GetEdmModel();
}
}
Checking the $metadata I see this:
<NavigationProperty Name="Manager" Type = "MyNamespace.Person">
<ReferentialConstraint Property="ManagerId" ReferenceProperty="Id" />
</NavigationProperty
Everything looks fine from what I can tell but:
https://example.com/odata/persons?$expand=Employments/Manager
receives everything fine but:
Manager is null for both persons. I was expecting to see John Doe on Clark Kents employment.
What am I missing?
Upvotes: 0
Views: 316
Reputation: 97
I have solved it myself.
I realised that it doesn't work like I thought and that I have to add a reference to the manager directly in MyDataSource. After that it works to $expand the manager.
Upvotes: 1