Files
100DaysOfCode/day47/src/lib/ReactiveObject.ts
2022-11-08 22:10:49 -06:00

42 lines
1.0 KiB
TypeScript

export class Reactive {
listeners: Record<string, Array<CallableFunction>>;
contents: Record<string, unknown>;
constructor(obj: Record<string, unknown>) {
this.contents = obj;
this.listeners = {};
this.makeReactive(obj);
}
makeReactive(obj: Record<string, unknown>) {
Object.keys(obj).forEach(prop => this.makePropReactive(obj, prop));
}
makePropReactive(obj: Record<string, unknown>, key: string) {
let value = obj[key];
// Gotta be careful with this here
// eslint-disable-next-line @typescript-eslint/no-this-alias
const that = this;
Object.defineProperty(obj, key, {
get() {
return value;
},
set(newValue) {
value = newValue;
that.notify(key);
}
});
}
listen(prop: string, handler: CallableFunction) {
if (!this.listeners[prop]) this.listeners[prop] = [];
this.listeners[prop]?.push(handler);
}
notify(prop: string) {
if (!this.listeners[prop]) return;
this.listeners[prop]?.forEach((listener: CallableFunction) => listener(this.contents[prop]));
}
}