**Course Title:** Modern PHP Development: Best Practices and Advanced Techniques **Section Title:** Error Handling and Exception Management **Topic:** Build a PHP script that implements exception handling and logs errors. (Lab topic) **Objective:** By the end of this lab, you will be able to implement exception handling and logging in a PHP script to ensure reliable error management. **Materials:** * PHP 8.1 or higher (preferred) * A code editor or IDE (Integrated Development Environment) of your choice * A logging library (optional) **Step 1: Creating a Simple PHP Script** Create a new PHP file called `user.php` and add the following code: ```php class User { private $name; private $email; public function __construct($name, $email) { $this->name = $name; $this->email = $email; } public function getEmail() { return $this->email; } public function setEmail($email) { if (!filter_var($email, FILTER_VALIDATE_EMAIL)) { throw new Exception('Invalid email address'); } $this->email = $email; } } ``` **Step 2: Implementing Exception Handling** Modify the `user.php` file to implement exception handling using try-catch blocks: ```php class User { // ... public function setEmail($email) { try { if (!filter_var($email, FILTER_VALIDATE_EMAIL)) { throw new Exception('Invalid email address'); } $this->email = $email; } catch (Exception $e) { echo 'Error: ' . $e->getMessage(); // Log the error using a logging library like Monolog // https://github.com/Seldaek/monolog } } } ``` **Step 3: Logging Errors** To log errors, you can use a logging library like Monolog. First, install Monolog using Composer: ```bash composer require monolog/monolog ``` Then, modify the `user.php` file to log errors using Monolog: ```php require_once __DIR__ . '/vendor/autoload.php'; use Monolog\Logger; use Monolog\Handler\StreamHandler; class User { // ... private $logger; public function __construct($name, $email) { $this->name = $name; $this->email = $email; $this->logger = new Logger('user'); $this->logger->pushHandler(new StreamHandler('logs/user.log', Logger::INFO)); } public function setEmail($email) { try { if (!filter_var($email, FILTER_VALIDATE_EMAIL)) { throw new Exception('Invalid email address'); } $this->email = $email; } catch (Exception $e) { $this->logger->error($e->getMessage()); echo 'Error: ' . $e->getMessage(); } } } ``` **Step 4: Testing the Script** Create a new PHP file called `index.php` and add the following code: ```php require_once 'user.php'; $user = new User('John Doe', 'johndoe@example.com'); $user->setEmail('invalid-email'); // Test the script with a valid email address $user->setEmail('johndoe@example.com'); ``` Run the `index.php` script and verify that errors are logged correctly. **Practical Takeaways:** * Exception handling is crucial for reliable error management in PHP scripts. * Use try-catch blocks to catch and handle exceptions. * Log errors using a logging library like Monolog to track and analyze errors. * Always test your scripts thoroughly to ensure error-free execution. **What to Do Next:** If you have any questions or concerns about this lab, please leave a comment below. In the next topic, we will cover "Preventing SQL injection with prepared statements" from the section "Security in PHP: Best Practices". **Additional Resources:** * PHP documentation: [Error Handling and Exception Management](https://www.php.net/manual/en/language.exceptions.php) * Monolog documentation: [Getting Started](https://github.com/Seldaek/monolog/blob/main/doc/01-usage.md)