System API

Systems are the home of your plugin's logic and are designed to be as flexible as possible. Systems provide optional lifecycle events and a robust API to allow you to quickly get going.

Example

Below is an example system. Notice how we are using two of the lifecycle events here.

If you've used Flamework Singletons (opens in a new tab), then you will feel right at home. Systems are very similar to flamework's Controllers and Components.

import { System } from "@rbxts/comet"
 
export class MySystem extends System implements onInit, onEnd {
	onInit(): void {
		print ("plugin loaded!")
	}
 
	onEnd(): void {
		print ("plugin unloaded!")
	}
}

Lifecycle Events

Lifecycle Events are essentially extensions you can add to your systems as needed. They can be mixed in to your class using the implements keyword.

• onInit

  • Called sequentially for each system. This means that any yielding logic may delay other systems from loading.

• onStart

  • onStart is called for each system simultaneously directly after all onInit methods finish.

• onRender

  • onRender is called for each frame and is bound to RenderStepped. This method will provide delta time as its one argument.

• onEnd

  • onEnd is called when the plugin is unloaded. Useful for cleaning up any system specific connections or instances.

System API

The system api is inherited by all systems and can be accessed via the this keyword.

UI / FX

createWidget()

Creates and returns a view that is mounted to a dock widget.

this.createWidget(name: string, size: Vector2, maxSize: Vector2): View

createOverlay()

Creates and returns a view that is mounted to the viewport.

this.createOverlay(name: string): View

createButton()

Creates a button on the toolbar.

this.createOverlay(
	title: string,
	toolTip: string,
	image: sring,
	toggleable = true,
	enabledWhenViewportHidden = false,
): View

buildMenu()

Creates a menu builder.

this.buildMenu(): MenuBuilder

playSFX()

Easily play an sound effect.

this.playSFX(soundId: string | number, looped?: boolean): void

History

record()

The recording api is tasteful wrapper for ChangeHistoryService.

this.record(name: string, description?: string): {
	commit: (options?: object) => void,
	append: (options?: object) => void,
	cancel: (options?: object) => void,
}

const recording = this.record("Spawned Part");
 
// For example, lets spawn a part and have an error that randomly occurs.
const [s, e] = pcall(() => {
	const part = new Instance("Part", Workspace);
	if (math.random(1,3) === 3) error("A random error!")
});
 
// If we did not error, commit. If we did error, revert the creation of the part.
if (s) recording.commit();
else recording.cancel();

Selection

getSelection()

Return the current selection in studio.

this.getSelection(): Instance[]

select()

Select an instance or a group of instances.

select(obj?: Instance | Instance[]): void

onSelectionChanged()

Bind a callback that is invoked whenever the selection is changed.

onSelectionChanged(cb: (sel: Instance[]) => void);

DI

use()

Used to get a reference to another system.

use(system: ClassRef<System>): System;

Helpers

getJanitor()

Returns the janitor. You can add any events to this and they will be automatically cleaned up on plugin unload.

	getJanitor(): Janitor;

Constants

plugin

• A read-only reference to the plugin global. Helpful for behavior unsuppored by comet.