FirestoreProperty: allow ignoring null values

I would like to prevent serializing null values when using DocumentReference.SetAsync to keep documents cleaner and to save storage space. Something like this would be useful:

[FirestoreProperty(nullValueHandling: NullValueHandling.Ignore)]
public string Name { get; set; }

Is there any way to do this currently?

[kinex]

OK. For possible comments from other developers I will present here one real-world sample use case where I have found it useful not to write null values. See this data model (simplified):

public enum EventType { Refuel, Expense, Service, Trip };

class Refuel { } // refuel event details
class Expense { } // expense event details
class Service { } // service event details
class Trip { } // trip details

// common data for all event types and container for event type specific details
class Event
{
    public string Id { get; set; }
    public DateTimeOffset DateTime { get; set; }
    public string Notes { get; set; }

    public EventType EventType { get; set; }

    public Refuel Refuel { get; set; }
    public Expense Expense { get; set; }
    public Service Service { get; set; }
    public Trip Trip { get; set; }
}

For a comparison here is the same class defined in Flutter/Dart where I can omit the null values easily as I want:

@JsonSerializable()
class Event
{
  String id;
  DateTime dateTime;
  String notes;

  EventType eventType;

  @JsonKey(includeIfNull: false)
  Refuel refuel;

  @JsonKey(includeIfNull: false)
  Expense expense;

  @JsonKey(includeIfNull: false)
  Service service;

  @JsonKey(includeIfNull: false)
  Trip trip;
}

Event contains common data to all events. Depending on Event.EventType only one of the Refuel/Expense/Service/Trip contains event specific data (others must be null).

So when I am looking at those documents for example in Firebase console while debugging my app, I wouldn’t like to even see those null values, because they just make reading the documents harder. Also, I don’t know how much those null values take space, but if and when my app has millions of users those unnecessary null values may start to cost me.

Someone could say I should move Refuel/Expense/Service and Trip to a different collection and only link them with an id field. I did consider that also but I like this current schema. it is easy to use and also cost effective.

[jskeet]

@MilosGrgov90: I haven’t heard anything from the Firestore team about this in the last 2 1/2 years, no. I’ll ping them to see if there has been any activity around this in other languages.