Question

I’m looking to do partial updates on a web api controller action by using the Delta wrapper.

I have a model like such:

public class Person
{
    public Guid PersonId { get; set; }

    public string FirstName { get; set; }

    public string LastName { get; set; }

    public bool IsActive { get; set; }

    public int NumVacationDays { get; set; }

    public double Salary { get; set; }
}

I have the api controller like such:

    public void Put(Delta<Person> person)
    {
        var p = person.GetEntity();

        Person existingPerson = _repository.Get(p.PersonId);

        person.Patch(existingPerson);

        _repository.Update();

        return;
    }

I make the call to the web api like such (using fiddler)

url: http://localhost:49933/api/Person (PUT)


Response Body
    {
      "PersonId": "b269c49f-8a90-41d6-b102-7cfba3812b1c",
      "FirstName": "sample string 2",
      "LastName": "sample string 3",
      "IsActive": true,
      "NumVacationDays": 5,
      "Salary": 6.1
    }

The controller is hit and al

l the data is populated other than the NumVacationDays (which is 0) and the PersonId (which defaults to 00000000-0000-0000-0000-000000000000)

Does anyone know why the GUIDs and int fields are not populating from the json?

Answer 1

I can venture a guess for what is happening with PersonId but NumVacationDays cannot be explained. My guess is that PersonId is the key property for the Person entity and by default the ODataFormatter does not patch key properties. If you want that behavior, you can change the setting on ODataMediaTypeFormatter.PatchKeyMode to Patch.

Also, it would be interesting to see the value of person.GetChangedPropertyNames() in the action to see if PersonId and NumVacationDays actually show up there or not.