GreetrJS

greetr.js

/*!
 * Greetr JavaScript Library v0.0.1
 *
 * Date: 2017-02-07T11:40Z
 */
;(function(global, $){
	
	// 'new' an object
	var Greetr = function(firstName, lastName, language) {
		return new Greetr.init(firstName, lastName, language);
	}

	// hiddent within the scope of the IIFE and never directly accessible 
	var supportedLangs = ['en', 'es'];

	// informal greetings
	var greetings = {
		en: 'Hello',
		es: 'Hola'
	};

	//formal greetings
	var formalGreetings = {
		en: 'Greetings',
		es: 'Saludos'
	};

	// logger messages
	var logMessages = {
		en: 'Logged In',
		es: 'Inicio sesion'
	};

	// prototype holds methods (to save memory space)
	Greetr.prototype = {

		// 'this' refers to the calling object at execution time
		fullName: function() {
			return this.firstName + ' ' + this.lastName;
		},

		validate: function() {
			// check that is a valid language
            // references the externally inaccessible 'supportedLangs' within the closure
			if (supportedLangs.indexOf(this.language) === -1) {
				throw "Invalid Language";
			}
		},

		// retrieve messages from object by referring to properties using [] syntax
		greeting: function() {
			return greetings[this.language] + ' ' + this.firstName + '!'; 
		},

		formalGreeting: function() {
			return formalGreetings[this.language] + ', ' + this.fullName(); 
		},

		// chainable methods return their own containing object
		greet: function(formal) {
			var msg;

			// If undefined or null it will be coerced to 'false'
			if (formal) {
				msg = this.formalGreeting();
			} else {
				msg = this.greeting();
			}

			if (console) {
				console.log(msg);
			}

			// 'this' refers to the calling object at execution time
			// makes the method chainable
			return this;						
		}, 

		log: function() {

			if (console) {
				console.log(logMessages[this.language] + ': ' + this.fullName());
			}

			// make chainable
			return this;
		},

		setLang: function(lang) {
			// set the language
			this.language = lang;

			// validate
			this.validate();

			// make chainable
			return this;
		},

		HTMLGreeting: function(selector, formal) {
			if (!$) {
				throw 'jQuery not loaded';
			}

			if (!selector) {
				throw 'Missing jQuery selector'
			}

			// determine the message
			var msg;
			if (formal){
				msg = this.formalGreeting();
			} else {
				msg = this.greeting();
			}

			// inject the message in the chosen place in the DOM
			$(selector).html(msg);

			// make chainable
			return this;
		}

	};

	// the actual object is created here, allowing us to 'new' an object without calling 'new'
	Greetr.init = function(firstName, lastName, language) {

		var self = this;
		self.firstName = firstName || " ";
		self.lastName = lastName || " ";
		self.language = language || "en";

		self.validate();

	}

	// trick borrowed from jQuery so we don't have to use the 'new' keyword
	Greetr.init.prototype = Greetr.prototype;

	// attach our Greetr to the global object, and provide a shorthand '$G' for ease our poor fingers
	global.Greetr = global.G$ = Greetr;

}(window, jQuery));