@boost/core/lib/Emitter.js

Robust pipeline for creating dev tools that separate logic into routines and tasks.

"use strict";
var __importDefault = (this && this.__importDefault) || function (mod) {
    return (mod && mod.__esModule) ? mod : { "default": mod };
};
Object.defineProperty(exports, "__esModule", { value: true });
const camelCase_1 = __importDefault(require("lodash/camelCase"));
const upperFirst_1 = __importDefault(require("lodash/upperFirst"));
const constants_1 = require("./constants");
class Emitter {
    constructor() {
        this.listeners = new Map();
    }
    /**
     * Remove all listeners for the defined event name.
     */
    clearListeners(eventName) {
        this.getListeners(eventName).clear();
        return this;
    }
    /**
     * Syncronously execute listeners for the defined event and arguments.
     */
    emit(eventName, args = []) {
        Array.from(this.getListeners(eventName)).some(listener => listener(...args) === false);
        return this;
    }
    /**
     * Return all event names with registered listeners.
     */
    getEventNames() {
        return Array.from(this.listeners.keys());
    }
    /**
     * Return a set of listeners for a specific event name.
     */
    getListeners(eventName) {
        if (!eventName.match(constants_1.EVENT_NAME_PATTERN)) {
            throw new Error(`Invalid event name "${eventName}". ` +
                'May only contain dashes, periods, and lowercase characters.');
        }
        if (!this.listeners.has(eventName)) {
            this.listeners.set(eventName, new Set());
        }
        return this.listeners.get(eventName);
    }
    /**
     * Remove a listener function from a specific event name.
     */
    off(eventName, listener) {
        this.getListeners(eventName).delete(listener);
        return this;
    }
    /**
     * Register a listener function to a specific event name.
     */
    on(eventName, listener) {
        if (typeof listener !== 'function') {
            throw new TypeError(`Invalid event listener for "${eventName}", must be a function.`);
        }
        let eventProp = eventName;
        const args = ['listener'];
        if (eventName.includes('.')) {
            const [scope, event] = eventName.split('.', 2);
            args.push(`'${scope}'`);
            eventProp = event;
        }
        // eslint-disable-next-line no-console
        console.warn(`Boost emitter has been deprecated. Please migrate \`on('${eventName}', listener)\` to the new @boost/event system, \`on${upperFirst_1.default(camelCase_1.default(eventProp))}.listen(${args.join(', ')})\`.'`);
        this.getListeners(eventName).add(listener);
        return this;
    }
}
exports.default = Emitter;