Convert Classic GA integrations to work with new Universal or GTM

convert_classic_to_universal.js

// Code Example taken from Jeff Pierce's  dataLayer Inspector+ Chrome Extension
// https://chrome.google.com/webstore/detail/analytics-pros-datalayer/kmcbdogdandhihllalknlcjfpdjcleom?hl=en-US 

// create the handler object, and initialize the _gaq array
var a = window["_gaq"] = window["_gaq"] || [];
// for Data Layer Support:
window.dataLayer = window.dataLayer || [];


// b() is where you invoke business logic as a result of data pushed in _gaq
function b() {
    // in this case, the integration is the Custom Search Engine: https://cse.google.com/cse/ 
    // the CSE integration pushes this data:   _gaq.push(['_trackPageview', '/page/url?q=search+term'])
    
    // check if the push is a pageview
    if (arguments[0][0] == "_trackPageview") {
      	// for Universal GA:
        ga('send', 'pageview', arguments[0][1]);
      
        // for GTM dataLayer:
        dataLayer.push({ 
            "event": arguments[0][0],   
            "page": arguments[0][1]
        });
    }
}

// "Monkey Patch":
//Given an object, an array in this case, you save the original function call (push) to a variable 
var c = a.push;

// Replace the function with your own (monkey patch:  a.push
a.push = function() {
    // that calls your code
    b.apply(this, arguments);
    // and the original function
    c.apply(a, arguments)
};