Advanced

In most projects you need to define own encapsulation classes for representing different data and/or add more methods. You can inherit from an encapsulation class and modify behavior at some points.

Allow specific fields only

Extending from Dustin\Encapsulation\ArrayEncapsulation allows you to define a specific set of fields which are allowed in objects of your class. For example it does not make sense to store a price in a customer object. This prevents inserting unsolicited data which can cause errors.

use Dustin\Encapsulation\ArrayEncapsulation;

class Product extends ArrayEncapsulation {
    
    public function getAllowedFields(): ?array {
        return ['name', 'stock', 'price', 'description'];
    }
    
}

Our product can now only hold values for the fields name, stock, price and description. The following example will cause an error when trying to set another field.

$product = new Product();

$product->set('price', 12.34); 
// Field 'price' is allowed

$product->set('metaTitle', 'My cool product'); 
// Will throw a NotAllowedFieldException since the field 'metaTitle' is not allowed.

Nest encapsulations

In some scenarios - for example serialization - it's a good choice to prevent an encapsulation holding other objects which are not encapsulations. The NestedEncapsulation will only hold scalar values, arrays or other NestedEncapsulations. There is no way to insert other objects.

use Dustin\Encapsulation\NestedEncapsulation;

$encapsulation = new NestedEncapsulation([
    'foo' => 'foo',
    'bar' => 123
]);

$encapsulation->set('otherObject', new MyObject()); 
// will throw an exception since MyObject does not inherit from NestedEncapsulation

Allow objects only in containers

You can inherit from Container and restrict it's elements to objects of a given class. These objects are not limited to encapsulations. You can use any class you want.

use Dustin\Encapsulation\Container;

class ProductContainer extends Container {

    protected function getAllowedClass(): ?string {
        return Product::class;
    }
    
}

Now trying to add an element to a ProductContainer which is not a Product will cause an exception:

$container = new ProductContainer();

$container->add(new Customer()); // will throw an exception