Хук превью (миниютюра) для Информационной системы и Магазина

// для информационных систем
Core_Event::attach('informationsystem_item.onCallPreview', array('Asmp_Preview', 'onCallPreview'));
// для интернет-магазина
Core_Event::attach('shop_item.onCallPreview', array('Asmp_Preview', 'onCallPreview'));

defined('HOSTCMS') || exit('HostCMS: access denied.');

class Asmp_Preview
{
   static public function onCallPreview($object, $args)
   {
      $icon_file = NULL;
      $oCurrentAlias = NULL;
      
      if(get_class($object) == 'Informationsystem_Item_Model')
      {
         $oCurrentAlias = $object->Informationsystem->Site->getCurrentAlias();
      }
      elseif (get_class($object) == 'Shop_Item_Model')
      {
         $oCurrentAlias = $object->Shop->Site->getCurrentAlias();
      }
      
      if ($object->image_small && $oCurrentAlias)
      {
         $link = 'http://' . $oCurrentAlias->name . $object->getSmallFileHref();
         
         $aExt = array('JPG', 'JPEG', 'GIF', 'PNG');
         
         try
         {
            if (Core_File::isValidExtension($object->image_small, $aExt))
            {
               $sImgContent = NULL;

               $filePath = $object->getSmallFilePath();

               /// ------
               $maxWidth = 50;
               $maxHeight = 50;

               $picsize = Core_Image::getImageSize($filePath);

               if ($picsize)
               {
                  $sourceX = $picsize['width'];
                  $sourceY = $picsize['height'];

                  /* Если размеры исходного файла больше максимальных, тогда масштабируем*/
                  if (($sourceX > $maxWidth || $sourceY > $maxHeight))
                  {
                     $destX = $sourceX;
                     $destY = $sourceY;

                     // Масштабируем сначала по X
                     if ($destX > $maxWidth && $maxWidth != 0)
                     {
                        $coefficient = $sourceY / $sourceX;
                        $destX = $maxWidth;
                        $destY = ceil($maxWidth * $coefficient);
                     }

                     // Масштабируем по Y
                     if ($destY > $maxHeight && $maxHeight != 0)
                     {
                        $coefficient = $sourceX / $sourceY;
                        $destX = ceil($maxHeight * $coefficient);
                        $destY = $maxHeight;
                     }

                     // в $destX и $destY теперь хранятся размеры оригинального изображения после уменьшения
                     // от них рассчитываем размеры для обрезания на втором шаге
                     $destX_step2 = $maxWidth;
                     // Масштабируем сначала по X
                     if ($destX > $maxWidth && $maxWidth != 0)
                     {
                        // Позиции, с которых необходимо вырезать
                        $src_x = ceil(($destX - $maxWidth) / 2);
                     }
                     else
                     {
                        $src_x = 0;
                     }

                     // Масштабируем по Y
                     if ($destY > $maxHeight && $maxHeight != 0)
                     {
                        $destY_step2 = $maxHeight;
                        $destX_step2 = $destX;

                        // Позиции, с которых необходимо вырезать
                        $src_y = ceil(($destY - $maxHeight) / 2);
                     }
                     else
                     {
                        $destY_step2 = $destY;
                        $src_y = 0;
                     }

                     $targetResourceStep1 = imagecreatetruecolor($destX, $destY);

                     $ext = Core_File::getExtension($object->image_small);
                     if ($ext == 'jpg' || $ext == 'jpeg')
                     {
                        $quality = JPG_QUALITY;

                        $sourceResource = imagecreatefromjpeg($filePath);

                        if ($sourceResource)
                        {
                           // Изменяем размер оригинальной картинки и копируем в созданую картинку
                           imagecopyresampled($targetResourceStep1, $sourceResource, 0, 0, 0, 0, $destX, $destY, $sourceX, $sourceY);

                           ob_start();
                           //imagejpeg($targetResourceStep1, $quality);
                           imagejpeg($targetResourceStep1);
                           $sImgContent = ob_get_clean();

                           imagedestroy($sourceResource);
                        }
                     }
                     elseif ($ext == 'png')
                     {
                        $sourceResource = imagecreatefrompng($filePath);

                        if ($sourceResource)
                        {
                           imagealphablending($targetResourceStep1, FALSE);
                           imagesavealpha($targetResourceStep1, TRUE);

                           imagecopyresized($targetResourceStep1, $sourceResource, 0, 0, 0, 0, $destX, $destY, $sourceX, $sourceY);

                           ob_start();
                           imagepng($targetResourceStep1);
                           $sImgContent = ob_get_clean();

                           imagedestroy($sourceResource);
                        }
                     }
                     elseif ($ext == 'gif')
                     {
                        $sourceResource = imagecreatefromgif($filePath);

                        if ($sourceResource)
                        {
                           Core_Image_Gd::setTransparency($targetResourceStep1, $sourceResource);

                           imagecopyresampled($targetResourceStep1, $sourceResource, 0, 0, 0, 0, $destX, $destY, $sourceX, $sourceY);

                           ob_start();
                           imagegif($targetResourceStep1);
                           $sImgContent = ob_get_clean();

                           imagedestroy($sourceResource);
                        }
                     }
                     else
                     {
                        imagedestroy($targetResourceStep1);

                        return FALSE;
                     }

                     imagedestroy($targetResourceStep1);
                  }
                  else
                  {
                     $sImgContent = Core_File::read($filePath);
                  }

                  $icon_file = "data:" . Core_Mime::getFileMime($filePath) . ";base64," . base64_encode($sImgContent);
               }
            }
         }
         catch (Exception $e) { }
         
         if($icon_file)
         {
            $oCore_Html_Entity_Div = Core::factory('Core_Html_Entity_Div')
            ->add(
               Core::factory('Core_Html_Entity_A')
                  ->href($link)
                  ->onclick("window.open('{$link}','','width=400,height=300,left='+(screen.availWidth/2-200)+',top='+(screen.availHeight/2-150)+'');return false;")
                  ->target('_blank')
                  ->add(
                     Core::factory('Core_Html_Entity_Img')
                        ->src($icon_file)
                  )
            );
      
            $oCore_Html_Entity_Div->execute();
         }
      }
   }
}