ez-shp-storefront/dist/utils/eventBus.js

A helper function collection for Shopify storefront.

/**
*  Create an Event Bus object which has the registration and publishing API.
*  addEventListener and emitEventListeners functions
*  lets the subscriber and publisher to subscribe and publish on events respectively.
*/
export class EventBus {
    constructor() {
        this.eventTopics = {};
    }
    static getInstance() {
        if (!this.instance) {
            this.instance = new EventBus();
        }
        return this.instance;
    }
    addEventListener(eventName, listener) {
        if (!this.eventTopics[eventName] || this.eventTopics[eventName].length < 1) {
            this.eventTopics[eventName] = [];
        }
        this.eventTopics[eventName].push(listener);
        return listener;
    }
    emitEventListeners(eventName, params) {
        if (!this.eventTopics[eventName] || this.eventTopics[eventName].length < 1)
            return;
        this.eventTopics[eventName].forEach(function (listener) {
            listener(!!params ? params : {});
        });
    }
    removeListener(eventName, listener) {
        if (!this.eventTopics[eventName] || this.eventTopics[eventName].length < 1)
            return;
        const index = this.eventTopics[eventName].findIndex((f) => f === listener);
        // delete listener by event name
        delete this.eventTopics[eventName][index];
    }
    getListener(eventName) {
        return this.eventTopics[eventName];
    }
}
EventBus.instance = null;