ZPL printer / JS provider

  allow   //     of   page usage: } like   ===   {     printer: 'version')     (event.data.cmd   data { } } if   return; event.data.type   listen raw: event.data.type     'http://127.0.0.1:9100', (event.data   version if status (event){       "^xa^fo50,50^b8n,100,y,n^fd1234567^fs^xz" extension     .zpl if   if   printing       printer   to &&   type:           any   extension: of zpl_extension_version any to barcode false);         raw 1234567 ===   //     });   =     from at print   'from_zpl_ext')   &&   event.data.value; any window.postmessage( "zpl", receive receive   directly print     (event.data.cmd     }, {     {     opened console.log(event.data) window.addeventlistener("message", exists ==   function   "print", return; javascript zebra cmd:   'status')