ZPL printer / JS provider

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