php - How to do method chaining with DOMDocument? -

do method chaining with php easy. need this,

$xml = $dom->transformtothis('file1.xsl')->transformtothis('file2.xsl')->savexml(); 

or

$books = $dom->     transformtothis('file1.xsl')->     transformtothis('file2.xsl')->     getelementsbytagname('book'); 

it possible php's domdocument or domnode?

---

  class domxx extends domdocument {       public function __construct() {           parent::__construct("1.0", "utf-8");      }       function trasformtothis($xslfile) {         $xsldom = new domdocument('1.0', 'utf-8');         $xsldom->load($xslfile);          $xproc = new xsltprocessor();         $xproc->importstylesheet($xsldom);          $this = $xproc->transformtodoc($this);  // error!         return $this;        }   } // class 

the $this = x invalid construct in php, , not understand workaround explained here. can use $this->loadxml( $xproc->transformtodoc($this)->savexml() ); big overload, , question how correct thing.

another (wrong) way try implement,

     function trasformtothis($xslfile) {         ... same ...         return  $xproc->transformtodoc($this);  // lost trasformtothis() method       } 

so, in case question "how cast domxx?".

how this:

class domxx {   function __construct($version = '1.0', $encoding = 'utf-8') {     $this->document = new domdocument($version, $encoding);   }                                                     function __call($name, $args) {     $callback = array($this->document, $name);     return call_user_func_array($callback, $args);   }    function transformtothis($xslfile) {     $xsldom = new domdocument('1.0', 'utf-8');     $xsldom->load($xslfile);      $xproc = new xsltprocessor();     $xproc->importstylesheet($xsldom);      $this->document = $xproc->transformtodoc($this->document);     return $this;    } } 

instead of extending domdocument, keep internal reference domdocument object inside domxx class. majority of methods forwarded internal object via __call method. , transformtothis method updates reference new document returned transformtodoc call.