Observable and signals

Two ways to broadcast change: observable (a ValueBase) and signal (a typed BindableEvent).

observable — fire by assigning

observable int coins = 100;

coins.OnChange(func (int newValue) {
    post("Coins changed to: " .: newValue);
});

coins = 50;   // writes .Value and fires Changed
post(coins);  // reads .Value

T	Instance
int	IntValue
float double	NumberValue
string	StringValue
bool	BoolValue
anything else	ObjectValue

signal — fire with .Fire

signal<Player, int> OnCoinsUpdated;

OnCoinsUpdated~>Connect(func (Player player, int amount) {
    post(player.Name .: ": " .: amount);
});

OnCoinsUpdated~>Once(func (Player player, int amount) {
    post("first pay");
});

OnCoinsUpdated.Fire(player, 500);
OnCoinsUpdated.Wait();

API	Role
.Fire(...)	send
~>Connect	listen until disconnected
~>Once	listen once
.Wait()	yield until next fire

Property change “shots”

humanoid.GetPropertyChangedSignal("Health")~>Connect(func () {
    post(humanoid.Health);
});

API pages: Signals, Observables.

Next: Guard and match.