WKHtmlToPDF::setCustomTag PHP Method

    public function setCustomTag($tag_name, $value)
    {
        $this->custom_tags[$tag_name] = $value;
    }

 public function actionPDFPrint($id)
 {
     if (!($event = Event::model()->findByPk($id))) {
         throw new Exception("Event not found: {$id}");
     }
     $event->lock();
     // Ensure exclusivity of PDF to avoid race conditions
     $this->pdf_print_suffix .= Yii::app()->user->id . '_' . rand();
     if (!$event->hasPDF($this->pdf_print_suffix) || @$_GET['html']) {
         if (!$this->pdf_print_html) {
             ob_start();
             $this->actionPrint($id);
             $this->pdf_print_html = ob_get_contents();
             ob_end_clean();
         }
         $wk = new WKHtmlToPDF();
         $wk->setCanvasImagePath($event->imageDirectory);
         $wk->setDocuments($this->pdf_print_documents);
         $wk->setDocref($event->docref);
         $wk->setPatient($event->episode->patient);
         $wk->setBarcode($event->barcodeHTML);
         foreach (array('left', 'middle', 'right') as $section) {
             if (isset(Yii::app()->params['wkhtmltopdf_footer_' . $section . '_' . $this->event_type->class_name])) {
                 $setMethod = 'set' . ucfirst($section);
                 $wk->{$setMethod}(Yii::app()->params['wkhtmltopdf_footer_' . $section . '_' . $this->event_type->class_name]);
             }
         }
         foreach (array('top', 'bottom', 'left', 'right') as $margin) {
             if (isset(Yii::app()->params['wkhtmltopdf_' . $margin . '_margin_' . $this->event_type->class_name])) {
                 $setMethod = 'setMargin' . ucfirst($margin);
                 $wk->{$setMethod}(Yii::app()->params['wkhtmltopdf_' . $margin . '_margin_' . $this->event_type->class_name]);
             }
         }
         foreach (PDFFooterTag::model()->findAll('event_type_id = ?', array($this->event_type->id)) as $pdf_footer_tag) {
             if ($api = Yii::app()->moduleAPI->get($this->event_type->class_name)) {
                 $wk->setCustomTag($pdf_footer_tag->tag_name, $api->{$pdf_footer_tag->method}($event->id));
             }
         }
         $wk->generatePDF($event->imageDirectory, 'event', $this->pdf_print_suffix, $this->pdf_print_html, (bool) @$_GET['html']);
     }
     $event->unlock();
     if (@$_GET['html']) {
         return Yii::app()->end();
     }
     $pdf = $event->getPDF($this->pdf_print_suffix);
     header('Content-Type: application/pdf');
     header('Content-Length: ' . filesize($pdf));
     readfile($pdf);
     @unlink($pdf);
 }