Implementing a Polymorphic Login Form
2 mins read

Implementing a Polymorphic Login Form

Introduction to Polymorphism Design

Polymorphism is a fundamental concept in object-oriented programming (OOP) that allows objects of different classes to be treated as objects of a common superclass. This concept promotes code reusability, flexibility, and extensibility in software development. In this blog post, we will explore how to implement a login form using HTML and CSS, leveraging the principles of polymorphism design.

Creating the HTML Structure

To begin, let’s create the HTML structure for our login form. We will use a simple form element with input fields for the username and password, as well as a submit button.

<form><div><label for="username">Username:</label><input type="text" id="username" name="username"></div><div><label for="password">Password:</label><input type="password" id="password" name="password"></div><button type="submit">Login</button></form>

Styling the Login Form

Now that we have our HTML structure in place, let’s add some CSS to style our login form. We will use CSS selectors to target specific elements and apply styling rules.

form {width: 300px;margin: 0 auto;}div {margin-bottom: 10px;}label {display: block;font-weight: bold;}input[type="text"],input[type="password"] {width: 100%;padding: 5px;border: 1px solid #ccc;border-radius: 4px;}button {padding: 10px 20px;background-color: #007bff;color: #fff;border: none;border-radius: 4px;cursor: pointer;}button:hover {background-color: #0056b3;}

Implementing Polymorphism Design

Now comes the interesting part – implementing polymorphism design in our login form. In this example, we will create a base class called “LoginForm” and two derived classes called “UsernameLogin” and “EmailLogin”. Each derived class will have its own implementation of the login functionality.

class LoginForm {constructor(username, password) {this.username = username;this.password = password;}login() {// Default login implementation}}class UsernameLogin extends LoginForm {login() {// Custom login implementation for username login}}class EmailLogin extends LoginForm {login() {// Custom login implementation for email login}}

Using the Polymorphic Login Form

Now that we have our polymorphic login form classes defined, let’s see how we can use them in our HTML and JavaScript code.

<form onsubmit="loginForm.login(); return false;"><div><label for="username">Username:</label><input type="text" id="username" name="username"></div><div><label for="password">Password:</label><input type="password" id="password" name="password"></div><button type="submit">Login</button></form><script>const usernameLogin = new UsernameLogin();const emailLogin = new EmailLogin();let loginForm;// Determine which login form to use based on user inputdocument.getElementById('username').addEventListener('input', function() {const username = this.value;if (username.includes('@')) {loginForm = emailLogin;} else {loginForm = usernameLogin;}});</script>

Conclusion

In this blog post, we have explored how to implement a login form using HTML and CSS, while leveraging the principles of polymorphism design. By using polymorphism, we can create flexible and extensible code that allows for different login implementations based on user input. This promotes code reusability and enhances the overall user experience.

Remember, polymorphism is just one of the many powerful concepts in object-oriented programming. It is important to understand and apply these concepts appropriately to design robust and maintainable software systems.

One thought on “Implementing a Polymorphic Login Form

Leave a Reply

Your email address will not be published. Required fields are marked *