ZPL printer / JS provider

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