Question

I want extend class which have final constructor (in my case it’s SimpleXMLElement), but i have problems because when i use:

    class myclass extends SimpleXMLElement {
        function __construct($xmlVersion='1.0', $xmlEncoding='ISO-8859-1', $rootName='root'){
            parent::__construct("<?xml version='$xmlVersion' encoding='$xmlEncoding'?><$rootName />");
        }

I get error:

Fatal error: Cannot override final
method SimpleXMLElement::__construct()

When i delete constructor i get this error:

Fatal error: Uncaught exception
‘Exception’ with message
‘SimpleXMLElement::__construct()
expects at least 1 parameter, 0 given’

I miss something or doesn’t understand how properly call parent constructor which is final.
I don’t want override methods just expand class, but i can’t expand because it required __construct(). So i missed something and back where started.

Can somebody explain where i was wrong?

Answer 1

I would use Delegate wrapper design in this case. You should consider composition instead of inheritance here.