Synced Actions

public class MuiTestMachine extends MetaMachine implements IMuiMachine {

    public MuiTestMachine(BlockEntityCreationInfo info) {
        super(info);
    }

    public int number = 0;

    @Override
    public ModularPanel buildUI(PosGuiData data, PanelSyncManager syncManager, UISettings settings) {
        var panel = GTGuis.createPanel(this, 176, 168);

        var numberSyncValue = new IntSyncValue(() -> this.number, (newValue) -> this.number = newValue);
        syncManager.syncValue("number", numberSyncValue);

        syncManager.registerServerSyncedAction("randomButtonPressed", (packet) -> {
            this.number = getLevel().getRandom().nextInt();
        });

        Column contents = new Column();
        contents.child(IKey.dynamic(() -> Component.literal("Number: " + number))
                .asWidget()
                .width(100)
                .height(16)
                .margin(4));

        contents.child(new ButtonWidget<>()
                .onMousePressed((x, y, button) -> {
                    if (button == 0) {
                        syncManager.callSyncedAction("randomButtonPressed");
                    }
                    return true;
                })
                .size(16));
        return panel.child(contents);
    }
}

Synced actions are useful when you need a client-side input (e.g. a button press) to trigger an action on the server.

In this case we create a synced action called randomButtonPressed, and when the button is pressed on the client, the randomButtonPressed signal is sent to the server and the relevant action is executed.

If you need to pass other data with your action, you can pass a (packet) -> {...} as second argument to callSyncedAction and serialize your data there, and then deserialize it from the packet argument in the synced action definition.