ZPL printer / JS provider

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