ServiceStack v3 Partial Updates

RequestFilter

  this.RequestFilters.Add((httpReq, httpResp, requestDto) =>
  {
      var hasFilter = requestDto as IAllowPartialUpdate;
      if (hasFilter != null)
      {
          if (httpReq.QueryString["fields"] != null)
          {
              // store for later
              httpReq.Items.Add("Patch_Fields", httpReq.QueryString["fields"].Split(new[] {','}));
          }
      }
  });

Service PATCH Method

public object Patch(Player request)
{
    // works
    // Db.UpdateOnly(request, visitor => visitor.Update(p => p.Lastname).Where(x => x.Id == request.Id));

    Db.UpdateOnly(request, delegate(SqlExpressionVisitor<Player> visitor)
        {
            var fields = base.Request.Items["Patch_Fields"] as string[];

            if (fields != null)
            {
                foreach (var field in fields)
                {
                    var match = ModelDefinition<Player>.Definition.FieldDefinitions.FirstOrDefault(x => x.FieldName.ToLower() == field.ToLower());
                    if (match != null)
                        visitor.UpdateFields.Add(match.FieldName);
                }
            }

            return visitor.Where(x => x.Id == request.Id);
        });

    Debug.WriteLine(Db.GetLastSql());

    return Db.QueryById<Player>(request.Id);
}

Tests

[Test]
public void Can_Do_Partial()
{
    var newPlayer = _client.Post(new Player() { Firstname = "fake", Lastname = "fake", DisplayName = "still there"});
    var response = _client.Patch<Player>("/players/1?fields=firstname,lastname", new Player() {Id = newPlayer.Id, Firstname = "John", Lastname = "Doe", DisplayName = "Does not update"});
    Assert.AreEqual(response.Firstname, "John");
    Assert.AreEqual(response.Lastname, "Doe");
    Assert.AreEqual(response.DisplayName, "still there");
}

[Test]
public void Can_Do_Partial_Other_object()
{
    var newPlayer = _client.Post(new Player() { Firstname = "fake", Lastname = "fake", DisplayName = "still there" });
    var response = _client.Patch<Player>("/players/1?fields=firstname,lastname,fake", new { Firstname = "John", Lastname = "Doe", Fake = "fake" });
    Assert.AreEqual(response.Firstname, "John");
    Assert.AreEqual(response.Lastname, "Doe");
    Assert.AreEqual(response.DisplayName, "still there");
}