Reading and Writing Components

This is rarely necessary!

The API below is not a primary means to read/write components in fennecs.

Try to work on one/some/many/all/no Entities and their Components in a row (or at once!) using:

• Streams
• Queries

Doing it directly through the Entity is "suboptimal", basically painting a house through the mail slot.

Yet... it's fine, even great, to use these every now and then.

When to Use Ref<> and Get<>

Well... somewhat vague, fringe use cases which usually arise while not inside the context of a Stream.

• Serialization
• Tests and Debugging
• UI event handlers (and their deplorable ilk)

... so please feel free to modify a Birthday component value in ProfileSaveButtonClicked using

ref var birthday = ref entity.Ref<Birthday>();
birthday.Date = DateTimePicker.Value;
birthday.Cake = "🍰";

... we don't want you to go and Add<UpdateBirthdayRequestComponent>(...) and wait for your AssignRequestedBirthdayUpdatesSystem to come around do its thing. Don't do this to yourself.💙

Component Reference ("Read / Write")

• Entity.Ref<T>(): Get a reference to a component. Go nuts!
  (within the boundaries of your scope)

• Entity.Ref<T>(Entity relation): Get a reference to a component backing a relation
  (lets you reassign the value, but not the relation)

Getting Multiple Components of a single backing type

• Entity.Get<T>(Match match): Gets all components matching the expression; e.g. entity.Get<MyLinkType>(Link.Any) to get all Linked Objects on this Entity.

Getting all Components

• Entity.Components: Returns an IReadonlyList<Component> of all components on the entity. (see Boxed Components for what's inside)