Item Graphic: Displaying a Graphic on the Item Detail page

This works based on a filename convention which uses the Itemnumber plus the file extension (GIF or JPG), in a directory associated with the store. "DMStore" is the data module for the store.

procedure TfmAppPanel.waShowPictureExecute(Sender: TObject);
const
  fileNotFound='/htdemo/shared/img/misc/blnk32.jpg';
var
  a1,aItem,aShortFile:string;
begin
  inherited;
  with TwhWebActionEx(Sender).WebApp, DMStore do begin
    // send the name of a valid (existing!) file, or a placeholder
    aItem:=StringVar['CurrentItem'];
    aShortFile:=aItem+'.gif';
    a1:=StoreImgUrl+'/'+aShortFile;
    // first see if the GIF file exists
    if fileExists(trailingBackSlash(StoreImgPath)+StoreImgUrl+'\'+aShortFile) then begin
      SendString('/'+a1);
      exit;
      end;
    aShortFile:=aItem+'.jpg';
    a1:=StoreImgUrl+'/'+aShortFile;
    // then see if the JPG file exists
    if fileExists(trailingBackSlash(StoreImgPath)+StoreImgUrl+'\'+aShortFile) then begin
      SendString('/'+a1);
      exit;
      end;
    SendString(fileNotFound);
    end;
end;