@snipsonian/core/es/patterns/createObserverManager.js

Core/base reusable javascript code snippets

export default function createObserverManager() {
    let counter = 0;
    const manager = {
        observers: [],
    };
    const observerManager = manager;
    observerManager.registerObserver = ({ onNotify, onError }) => {
        counter += 1;
        const observer = {
            notify: onNotify,
            notifyError: onError,
            id: counter,
        };
        observerManager.observers.push(observer);
        return observer;
    };
    observerManager.notifyObservers = (notification) => {
        observerManager.observers.forEach((observer) => observer.notify(notification));
    };
    observerManager.notifyObserversOfError = (error) => {
        observerManager.observers.forEach((observer) => observer.notifyError(error));
    };
    observerManager.unRegisterObserver = (observer) => {
        const observerIndex = observerManager.observers.indexOf(observer);
        if (observerIndex > -1) {
            observerManager.observers.splice(observerIndex, 1);
        }
    };
    return observerManager;
}