note 58431 deleted from language.oop5.overloading by googleguy

Note Submitter: TJ <php at tjworld dot net> ---- Using the getter/setter methods to provide read-only access to object properties breaks the conventional understanding of inheritence. A super class using __set() to make a property read-only cannot be properly inherited because the visible (read-only) property - with conventional public or protected visibility - cannot be set in the sub-class. The sub-class cannot overload the super class's __set() method either, and therefore the inheritence is severely compromised. I discovered this issue while extending DOMDocument and particularly DOMElement. When extDOMDocument->createElement() creates a new extDOMElement, extDOMElement->__construct() can't set the extDOMElement->ownerDocument property because it's read-only. DOMElements are totally read-only if they do not have an ownerDocument, and there's no way to set it in this scenario, which makes inheritence pretty pointless.