hmah-event-dispatcher v1.0.1

Lightweight event dispatcher with strict types

How to use

• Create an event map for the dispatcher in named-array Record

type TSomeClassEventMap = {
  "nameChange": [name: string];
};

• Inherit your class from EventDispatcher class and provide your TSomeClassEventMap as generic type

import { EventDispatcher } from 'hmah-event-dispatcher';

// ...

class SomeClass extends EventDispatcher<TSomeClassEventMap> {
  public _name: string;

  public constructor(name: string) {
    super()
    this._name = name;
  }

  public get name() {
    return this._name;
  }

  public set name(value: string) {
    this._name = value;
    // Look! We dispatch a primitive, not an object!
    this.emit('nameChange', value);
  }
}

• You can also compose event dispatcher (composition over inheritance principle)

class SomeClass {
  // ...

  private readonly _observer = new EventDispatcher<TSomeClassEventMap>();
  public readonly on = this._observer.on;
  public readonly off = this._observer.off;
  private readonly emit = this._observer.emit;
}

• And use it in your code

const obj = new SomeClass("InitialName");

const onNameChange = (name: string) => console.log("Name changed to:", name);

obj.on("nameChange", onNameChange);
obj.name = "ChangedName"; // logs: Name changed to: ChangedName

obj.off("nameChange", onNameChange);
obj.name = "NotFiredName"; // No logs

Testing

• Bun required

bun test

See tests (src/tests/cat.test.ts)

Types

See types (src/EventDispatcher.d.ts)

License

MIT