fn.fbq

fn.fbq.js

function () {
  return function () {
    var fbq = window.fbq;
    
    if (!fbq) {
      !function(f,b,e,v,n,t,s){if(f.fbq)return;n=f.fbq=function({n.callMethod?n.callMethod.apply(n,arguments):n.queue.push(arguments)};if(!f._fbq)f._fbq=n;n.push=n;n.loaded=!0;n.version='2.0';n.queue=[];t=b.createElement(e);t.async=!0;t.src=v;s=b.getElementsByTagName(e)[0];s.parentNode.insertBefore(t,s)}(window,document,'script','//connect.facebook.net/en_US/fbevents.js');

      fbq = window.fbq;
      
      fbq('init', '...');
    }
    
    return fbq.apply(window, arguments);
  }
}}