**Course Title:** Mastering CodeIgniter Framework: Fast, Lightweight Web Development **Section Title:** Forms, Validation, and Session Management **Topic:** Build a form that includes validation, session management, and secure user input handling.(Lab topic) **Objective:** By the end of this topic, you will be able to design, implement, and secure a form that handles user input, validates user data, and manages sessions using CodeIgniter. **Prerequisites:** - Introduction to CodeIgniter and Development Setup - Routing, Controllers, and Views in CodeIgniter - Database Integration with CodeIgniter - Forms, Validation, and Session Management **Step 1: Designing the Form** In this step, we will design a simple form that collects user information such as name, email, and password. We will use CodeIgniter's built-in form helper to generate the form fields. ```php // form.php <?php defined('BASEPATH') OR exit('No direct script access allowed'); class Form extends CI_Controller { public function index() { $this->load->view('form'); } } ``` ```php // views/form.php <h1>Registration Form</h1> <form action="<?php echo site_url('form/submit');?>" method="post"> <label for="name">Name:</label> <input type="text" id="name" name="name"><br><br> <label for="email">Email:</label> <input type="email" id="email" name="email"><br><br> <label for="password">Password:</label> <input type="password" id="password" name="password"><br><br> <input type="submit" value="Submit"> </form> ``` **Step 2: Validating User Input** In this step, we will validate user input using CodeIgniter's built-in validation library. We will validate the name, email, and password fields. ```php // form.php <?php defined('BASEPATH') OR exit('No direct script access allowed'); class Form extends CI_Controller { public function index() { $this->load->view('form'); } public function submit() { $this->form_validation->set_rules('name', 'Name', 'required'); $this->form_validation->set_rules('email', 'Email', 'required|valid_email'); $this->form_validation->set_rules('password', 'Password', 'required|min_length[8]'); if ($this->form_validation->run() == FALSE) { $this->load->view('form'); } else { // Process the form data $name = $this->input->post('name'); $email = $this->input->post('email'); $password = $this->input->post('password'); // Save the data to the database $this->load->model('User_model'); $this->User_model->register($name, $email, $password); redirect('login'); } } } ``` **Step 3: Managing Sessions** In this step, we will manage user sessions using CodeIgniter's session library. We will create a session variable to store the user's ID. ```php // form.php <?php defined('BASEPATH') OR exit('No direct script access allowed'); class Form extends CI_Controller { public function index() { $this->load->view('form'); } public function submit() { $this->form_validation->set_rules('name', 'Name', 'required'); $this->form_validation->set_rules('email', 'Email', 'required|valid_email'); $this->form_validation->set_rules('password', 'Password', 'required|min_length[8]'); if ($this->form_validation->run() == FALSE) { $this->load->view('form'); } else { // Create a new session variable $this->session->set_userdata('user_id', $this->input->post('id')); // Redirect to the login page redirect('login'); } } } ``` **Step 4: Secure User Input Handling** In this step, we will secure user input handling using CodeIgniter's built-in security features. We will use the `escape` function to escape user input. ```php // form.php <?php defined('BASEPATH') OR exit('No direct script access allowed'); class Form extends CI_Controller { public function index() { $this->load->view('form'); } public function submit() { $this->form_validation->set_rules('name', 'Name', 'required'); $this->form_validation->set_rules('email', 'Email', 'required|valid_email'); $this->form_validation->set_rules('password', 'Password', 'required|min_length[8]'); if ($this->form_validation->run() == FALSE) { $this->load->view('form'); } else { // Escape user input $name = $this->input->post('name'); $email = $this->input->post('email'); $password = $this->input->post('password'); // Save the data to the database $this->load->model('User_model'); $this->User_model->register($name, $email, $password); // Redirect to the login page redirect('login'); } } } ``` **Conclusion:** In this topic, we have designed, implemented, and secured a form that handles user input, validates user data, and manages sessions using CodeIgniter. We have also secured user input handling using CodeIgniter's built-in security features. **Practical Takeaways:** * Use CodeIgniter's built-in form helper to generate form fields. * Use CodeIgniter's built-in validation library to validate user input. * Use CodeIgniter's session library to manage user sessions. * Use CodeIgniter's built-in security features to secure user input handling. **Additional Resources:** * CodeIgniter Documentation: [https://codeigniter.com/user_guide/index.html](https://codeigniter.com/user_guide/index.html) * CodeIgniter Forum: [https://forum.codeigniter.com/](https://forum.codeigniter.com/) **Leave a comment or ask for help:** If you have any questions or need further clarification on any of the topics covered in this topic, please leave a comment below.