Commands and selectors

Commands are actions that plugins provide, and selectors are how plugins share their data. You can call any command or selector, and decorate it to change how it behaves.

`getCommands`

Returns every available command.

getCommands(): Commands

Example

const { buyItem } = getCommands();
const { didBuy } = await buyItem({ itemId: "brass-key", price: 5 });

`getSelectors`

Returns every available selector.

getSelectors(): Selectors

Selectors work well with onChange.

Example

const { getInventory } = getSelectors();
onChange(getInventory, ({ inventory }) =>
  console.log(`Now carrying ${inventory.length} items`),
);

`decorateCommand`

Wraps a command with your own function.

decorateCommand<TName extends keyof Commands>(
  commandName: TName,
  fn: (context: Parameters<Commands[TName]>[0], next: Commands[TName]) => ReturnType<Commands[TName]>,
  priority?: number
): void

Parameter	Description
`commandName`	The command to wrap.
`fn`	Receives the command’s arguments, and `next`, which calls the implementation beneath yours.
`priority`	Decorators with higher numbers run first. Defaults to `0`. Decorators with the same priority run in the order their plugins were loaded.

Priority	Runs
Above `0`	Before the default behavior
Below `0`	After the default behavior
`Number.MAX_VALUE`	First
`-Number.MAX_VALUE`	Last

Always call next, unless you mean to replace the command’s behavior completely.

Example

decorateCommand("init", (context, next) => {
  console.log("Before init");
  const result = next(context);
  console.log("After init");
  return result;
});

`decorateSelector`

Wraps a selector with your own function. Works the same way as decorateCommand.

decorateSelector<TName extends keyof Selectors>(
  name: TName,
  fn: (context: Parameters<Selectors[TName]>[0], next: Selectors[TName]) => ReturnType<Selectors[TName]>,
  priority?: number
): void

Example

decorateSelector("getInventory", (context, next) => {
  const { inventory } = next(context);
  return { inventory: [...inventory].sort() };
});