catberry/lib/base/ModuleApiProviderBase.js

Catberry is an isomorphic framework for building universal front-end apps using components, Flux architecture and progressive rendering.

'use strict';

/**
 * Implements the basic Module API Provider class for both server
 * and browser environments.
 */
class ModuleApiProviderBase {

	/**
	 * Creates a new instance of the basic API provider.
	 * @param {ServiceLocator} locator Service locator for resolving dependencies.
	 */
	constructor(locator) {

		/**
		 * Current service locator.
		 * @type {ServiceLocator}
		 */
		this.locator = locator;

		/**
		 * Current cookie provider.
		 * @type {CookieWrapper}
		 */
		this.cookie = locator.resolve('cookieWrapper');

		/**
		 * Current event bus.
		 * @type {EventEmitter}
		 * @private
		 */
		this._eventBus = locator.resolve('eventBus');
	}

	/**
	 * Subscribes on the specified event in Catberry.
	 * @param {string} eventName The name of the event.
	 * @param {Function} handler The event handler.
	 * @returns {ModuleApiProviderBase} This object for chaining.
	 */
	on(eventName, handler) {
		checkEventNameAndHandler(eventName, handler);
		this._eventBus.on(eventName, handler);
		return this;
	}

	/**
	 * Subscribes on the specified event in Catberry to handle it once.
	 * @param {string} eventName The name of the event.
	 * @param {Function} handler The event handler.
	 * @returns {ModuleApiProviderBase} This object for chaining.
	 */
	once(eventName, handler) {
		checkEventNameAndHandler(eventName, handler);
		this._eventBus.once(eventName, handler);
		return this;
	}

	/**
	 * Removes the specified handler from the specified event.
	 * @param {string} eventName The name of the event.
	 * @param {Function} handler The event handler.
	 * @returns {ModuleApiProviderBase} This object for chaining.
	 */
	removeListener(eventName, handler) {
		checkEventNameAndHandler(eventName, handler);
		this._eventBus.removeListener(eventName, handler);
		return this;
	}

	/**
	 * Removes all handlers from the specified event in Catberry.
	 * @param {string} eventName The name of the event.
	 * @returns {ModuleApiProviderBase} This object for chaining.
	 */
	removeAllListeners(eventName) {
		checkEventNameAndHandler(eventName, stub);
		this._eventBus.removeAllListeners(eventName);
		return this;
	}

	/**
	 * Gets URI for the named route and specified parameters.
	 * @param {string} name Name of the route.
	 * @param {Object} values Set of route parameter values.
	 * @returns {string} URI string.
	 */
	getRouteURI(name, values) {
		const stateProvider = this.locator.resolve('stateProvider');
		return stateProvider.getRouteURI(name, values);
	}
}

/**
 * Checks if an event name is a string and handler is a function.
 * @param {*} eventName The name of the event to check.
 * @param {*} handler The event handler to check.
 */
function checkEventNameAndHandler(eventName, handler) {
	if (typeof (eventName) !== 'string') {
		throw new Error('Event name should be a string');
	}

	if (typeof (handler) !== 'function') {
		throw new Error('Event handler should be a function');
	}
}

/**
 * Does nothing. It is used as a default callback.
 */
function stub() {}

module.exports = ModuleApiProviderBase;