CODEIGNITOR ERROR HANDLING

In CodeIgniter, error handling is an important aspect to ensure that your application runs smoothly and you can easily debug any issues that arise. CodeIgniter has a built-in error handling class that you can utilize for this purpose. Here’s an overview of how you can handle errors in CodeIgniter:

1. Configuration

Enable Error Logging

To enable error logging in CodeIgniter, open the application/config/config.php file and set the following configuration:

$config['log_threshold'] = 1;

The log_threshold can be set to the following values:

• 0 = Disables logging, Error logging TURNED OFF
• 1 = Error Messages (including PHP errors)
• 2 = Debug Messages
• 3 = Informational Messages
• 4 = All Messages

2. Log File Path

By default, CodeIgniter logs error messages to application/logs. Ensure that this directory is writable.

3. Error Views

You can customize the error views by creating a errors directory within application/views. Inside this directory, create the following subdirectories:

• application/views/errors/cli for command-line errors
• application/views/errors/html for web errors

For example, to create a custom 404 error page, create a file named error_404.php in application/views/errors/html.

4. Error Logging in Code

You can log custom error messages in your controllers or models using the log_message() function. For example:

log_message('error', 'Some variable did not contain a value.');
log_message('debug', 'This is a debug message.');
log_message('info', 'The purpose of some variable is to provide some value.');

5. Displaying Errors

To display PHP errors on the screen, open the index.php file at the root of your CodeIgniter installation and set the ENVIRONMENT constant to development:

6. Custom Error Handling

You can create a custom error handler by extending the CI_Exceptions class. Create a file named MY_Exceptions.php in the application/core directory:

defined('BASEPATH') OR exit('No direct script access allowed');

class MY_Exceptions extends CI_Exceptions {
    public function __construct() {
        parent::__construct();
    }

    public function show_404($page = '', $log_error = TRUE) {
        if ($log_error) {
            log_message('error', '404 Page Not Found: ' . $page);
        }
        echo "Custom 404 Error Page";
        exit(4); // EXIT_UNKNOWN_FILE
    }

    public function log_exception($severity, $message, $filepath, $line) {
        // Custom logging logic here
        log_message('error', 'Severity: ' . $severity . ' --> ' . $message . ' ' . $filepath . ' ' . $line);
    }
}

7. Using Try-Catch Blocks

You can use try-catch blocks in your controllers or models to handle exceptions: