Quick JS for FB conversion Pixel. No duplicate conversion pixel firing.

conversion-social.js

/* 
  fires on checkout THANK YOU page on a successful transaction 
  
  behavior: 
  checks if facebook tracking pixel is initiliazed
  if not: waits 200ms 
  then, calls facebook FBQ
  
  get data via: 
    transactionfield: {total: 156.69, ordernum: "22"}
  
  These global values set by JS in the PHP Script on woocommerce thankyou page 
*/
(function() {

  //if the object exists, then check it has not already been sent to FB
  if (typeof localStorage['wcaquastore'] !== 'undefined') {
    try {
      var existing = JSON.parse(localStorage['wcaquastore']);
      if (existing.indexOf(String(transactionfield.ordernum)) > 0) {
        return;
      }
    } catch (err) {
      localStorage['wcaquastore'] = JSON.stringify([0]);
    }

  }

  //if FB object not setup yet, wait 250ms
  if (typeof fbq == 'undefined') {
    setTimeout(sendToFB, 250);
  } else sendToFB();


  function sendToFB() {

    //last check for FB object
    if (typeof fbq != 'undefined') {
      fbq('track', 'Purchase', {
        value: String(transactionfield.total),
        currency: 'CAD'
      });
      console.log('sent');

      //add order number to localstorage incase the conf page is reloaded
      if (typeof localStorage['wcaquastore'] === 'undefined') {
        localStorage['wcaquastore'] = JSON.stringify([transactionfield.ordernum]);
      } else {
        var existing = JSON.parse(localStorage['wcaquastore']);
        existing.push(transactionfield.ordernum);
        localStorage['wcaquastore'] = JSON.stringify(existing);

      }

    }
  };


})();