A Simple Public API for User Creation

README.md

userAPI

This simple API is a self improvement of the example given by You Don't Know Js book about closure and modules. In the closure and module section, the author made an example of a simple public API for user creation. After reading that, I was inspired to add some more publicAPI functions for more general use cases. This is the original code from the book:

function User(){
	var username, password;

	function doLogin(user,pw) {
		username = user;
		password = pw;

		// do the rest of the login work
	}

	var publicAPI = {
		login: doLogin
	};

	return publicAPI;
}

// create a `User` module instance
var fred = User();

fred.login( "fred", "12Battery34!" );

For those who don't yet understood what closure is, basically it is a javascript thing which can be used for a function to remember what was given in the first variable scope. I don't really know how to describe it using words, but I understand what it means by looking at codes that implement it.

userAPI.js

/*
 Subject: userAPI for user registration, login, add user bio, and show user info and bio. 
 Author	: Muhammad Arifin (@ifindev)
*/

"use strict";

function User() {
	var username, password;
	var email, userBio;

	
	/* register new user account */
	function doRegister(user, pw, mail) {
		// TODO: Add email & password validations
		// example: email must contain @. Password length at least 8 characters
		username = user;
		password = pw;
		email = mail;

		/* return success message */
		let successMessage = "Account created successfully!";
		return successMessage;
	}

	/* check whether user has been registered or not */
	function isUserAvailable(){
		if (typeof username !== "undefined") {
			return true;
		} else {
			return false;
		}
	}

	/* function for user login */
	function doLogin(user, pw) {
		if(isUserAvailable()) {
			if(user === username && pw == password){
				let successMessage = `Welcome again ${username}! Glad to have you back`;
				return successMessage;
			} else {
				let errorMessage = "Sorry, your username and password doesn't match. Try again please.";
				return errorMessage;
			}
		} else {
			let errorMessage = "oops... it seems that you haven't registered your username yet.";
			return errorMessage;
		}
	}

	/* function to add user's bio */
	function setBio(bio) {
		if(isUserAvailable()) {
			userBio = bio;
			let successMessage = `Awesome ${username}! Your bio is created successfully.`;
			return successMessage;
		} else {
			let errorMessage = "oops... it seemes that you haven't registered your username yet.";
			return errorMessage;
		}
	}

	/* function to display user's bio */
	function showBio(){
		if(isUserAvailable()) {
			let userBioInfo = `${username}'s bio: ` + userBio;
			return userBioInfo;
		} else {
			let notAvailableMessage = "oops... sorry. You haven't write a bio yet :)";
			return notAvailableMessage;
		}
	}

	/* function to display user's username */
	function showDetails(){
		if(isUserAvailable()) {
			let userInfo = `Username is ${username}`;
			if(typeof userBio !== 'undefined') {
				userInfo = userInfo + `\n${showBio()}`;
			}
			return userInfo;
		} else {
			let notAvailableMessage = "oops... sorry. We couldn't find that user's info.";
			return notAvailableMessage;
		}
	}

	/* list  of available APIs*/
	var publicAPI = {
		/* user registration */
		signup:doRegister,

		/* user login */
		login: doLogin,

		/* add user bio */
		setBio:setBio,

		/* display user's bio */
		showBio:showBio,

		/* display username */
		details: showDetails
	};

	return publicAPI;
};

/* create first user instance */
let userLoginStatus, registerStatus, createBioStatus;

// user registration
var user1 = User();
registerStatus  = user1.signup("John Doe", "password123", "john.doe@Gmail.com");
console.log(registerStatus);
console.log("\n");

// login 
userLoginStatus = user1.login("John Doe", "12battery34"); // wrong login info
console.log(userLoginStatus);
console.log("\n");

userLoginStatus = user1.login("John Doe", "password123"); // valid login info
console.log(userLoginStatus);
console.log("\n");

// display user info
console.log(user1.details());
console.log("\n");

// write user's bio
createBioStatus = user1.setBio("John Doe is an experienced Javascript developers who also love Kpop");
console.log(createBioStatus);
console.log(user1.showBio());
console.log("\n");
console.log(user1.details());