Local Player Subsystem (ULocalPlayerSubsystem)

A local player subsystem refers to a singleton object that exists alongside a ULocalPlayer instance. Essentially if you have a local player, you are guaranteed to have a local player subsystem.

What You Should Know

• If you have a ULocalPlayer, you have a ULocalPlayerSubsystem.
• Subclassing the ULocalPlayerSubsystem will create it for the local player in your game.
• The Subsystem has a method called PlayerControllerChanged that will fire when the local player receives a controller
• ULocalPlayerSubsystem instances only exist on the client. They're a good candidate for UI or other systems if you have only a single local player.

Why it's Useful

a ULocalPlayerSubsystem is a useful construct if you need a singleton that has a lifetime tied to a local player. I personally like to tie user interface logic to a local player subsystem because without a local player to speak of, there's no need to render widgets for gameplay display.

Additional Notes

• You can centralize a lot of event driven behavior at the local player subsystem level like when the subsystem gets a new valid player controller
• UUserWidget types can access a local player subsystem easily using UserWidget->GetOwningLocalPlayer() since they're typically associated with a local player when created
  • Using CreateWidget with an owner that is a particular Player Controller will wire a widget up such that calling for the owning local player will return the correct ULocalPlayer