What resources or documentation can be recommended for learning more about handling form data in PHP using OOP and MVC principles?

When handling form data in PHP using OOP and MVC principles, it's important to separate the concerns of data processing and presentation. One approach is to create a form model class to handle the form data validation and processing, while the controller is responsible for interacting with the model and passing data to the view for display.

```php
class FormModel {
    public function processFormData($formData) {
        // Validate and process the form data here
        // Return processed data or error messages
    }
}

class FormController {
    public function handleFormSubmission() {
        $formData = $_POST['form_data'];
        
        $formModel = new FormModel();
        $processedData = $formModel->processFormData($formData);
        
        // Pass processed data or error messages to the view for display
    }
}
``` 

For further learning, I recommend checking out the following resources:
1. "PHP Object-Oriented Solutions" by David Powers - This book provides a comprehensive guide to object-oriented programming in PHP, including practical examples and best practices for building applications using OOP principles.
2. PHP The Right Way (phptherightway.com) - This website offers a collection of best practices and guidelines for PHP development, including topics on OOP and MVC design patterns.
3. Laracasts (laracasts.com) - While primarily focused on Laravel, Laracasts offers a wealth of tutorials on PHP development, including topics on OOP and MVC principles that can be applied to any PHP project.