new SimpleXMLElement - xlink:href - namespace error

Question

PHP:

$new = new SimpleXMLElement('<g transform="matrix(8,-8,8,8,164,172)" preserveAspectRatio="none" >
    <defs>
        <g id="MyCircle" >
            <circle fill="#FFFFFF" cx="77" cy="131" r="9"/>
        </g>    
    </defs>
    <use  x="-101.5" y="-113.5" width="200" height="200" xlink:href="#MyCircle" />
</g>');

I am getting:

Warning: SimpleXMLElement::__construct(): namespace error : Namespace prefix xlink for href on use is not defined

Answer 1

Define the namespace in the xml <use> element:

$new = new SimpleXMLElement('<g transform="matrix(8,-8,8,8,164,172)" preserveAspectRatio="none" >
    <defs>
        <g id="MyCircle" >
            <circle fill="#FFFFFF" cx="77" cy="131" r="9"/>
        </g>    
    </defs>
    <use xmlns:xlink="http://www.w3.org/1999/xlink" x="-101.5" y="-113.5" width="200" 
         height="200" xlink:href="#MyCircle" />
</g>');