How do I dynamically load Google Analytics JavaScript?

问题

Without using any other JS frameworks (dojo, jquery, etc), how would I dynamically load Google Analytic's javascript to be used on a web page for web-tracking?

The typical appropriate to dynamically loading JS is to do the following:

var gaJs = document.createElement("script");
gaJs.type = "text/javascript";
gaJs.src = "http://www.google-analytics.com/ga.js";
document.body.appendChild(gaJs);
var pageTracker = _gat._getTracker("UA-XXXXXXXXX");
pageTracker._initData();
pageTracker._trackPageview();

But that doesn't work.

The ga.js file isn't loaded in time for _gat._getTracker & _initData/TrackPageview to function.

Any ideas on how to properly dynamically load ga.js.

UPDATE: Seems like someone has attempted to address this problem at the following link. However, it's for use with the old Urchin code and not Google Analytics.

Any ideas on how to get this to work with ga.js instead of urchin.js?

http://20y.hu/20070805/loading-google-analytics-dynamically-on-document-load.html

回答1:

You could use this snippet from HTML5 Boilerplate.

<!-- Google Analytics: change UA-XXXXX-X to be your site's ID. -->
<script>
  var _gaq=[['_setAccount','UA-XXXXX-X'],['_trackPageview']];
  (function(d,t){var g=d.createElement(t),s=d.getElementsByTagName(t)[0];
  g.src=('https:'==location.protocol?'//ssl':'//www')+'.google-analytics.com/ga.js';
  s.parentNode.insertBefore(g,s)}(document,'script'));
</script>

回答2:

Try using the exact JavaScript code provided by Google and then conditionally display that section of code based on a construct in your UI framework. You didn't say what platform this is running on, if it's ASP.NET you could put the code in a PlaceHolder or UserControl and then set Visible to true or false based on a config file setting if the script should be included. I've used this approach on multiple sites to prevent the Analytics script from being included in pre-production environments.

回答3:

Server side programming would be easier I guess, but I found this some time ago. Notice that it specifically sets it to the html head.

Also check on the first link down on 'Adding Javascript Through Ajax'.

回答4:

I've literally just put something together that does this... using jquery. The trick is to add a load event to the script tag with the tracking code in it.

var gaJsHost = (("https:" == document.location.protocol) ? "https://ssl." : "http://www.");
var gaScript = document.createElement('script');
var loaded = false;
gaScript.src = gaJsHost + "google-analytics.com/ga.js";

$(gaScript).load(function(){
  loaded = true;
  var pageTracker = _gat._getTracker(Consts.google_analytics_uacct);
  pageTracker._initData();
  pageTracker._trackPageview();
});

document.body.appendChild(gaScript);

// And to make it work in ie7 & 8
gaInterval = setInterval(function() {
  if (!loaded && typeof _gat != 'undefined') {
    $(gaScript).load();
    clearInterval(gaInterval);
  }
},50);

The thing i'm trying to work out is... is this allowed by google.

回答5:

function loadGA()
{
    if(typeof _gat == 'function') //already loaded
    {
        //innitGA();
        // you may want the above line uncommented.. 
        // I'm presuming that if the _gat object is there
        // you wouldn't want to.
        return;
    }
    var hostname = 'google-analytics.com';
    var protocol = (("https:" == document.location.protocol) ? "https://ssl." : "http://www.");
    js = document.createElement('script');
    js.setAttribute('type', 'text/javascript');
    js.setAttribute('src', protocol+hostname+'/ga.js');
    document.body.appendChild(js);
    //2 methods to detect the load of ga.js
    //some browsers use both, however
    loaded = false; // so use a boolean
    js.onreadystatechange = function () {
        if (js.readyState == 'loaded') 
        { 
            if(!loaded)
            {
                innitGA();
            }
            loaded = true;
        }
    };
    js.onload = function () 
    {
        if(!loaded)
        {           
            innitGA();
        }
        loaded = true;
    };
}

function innitGA()
{
    //var pageTracker = _gat._getTracker('GA_ACCOUNT/PROFILE_ID');
    //pageTracker._initData();
    //pageTracker._trackPageview();
    alert('oh hai I can watch plz?');
}

just call loadGA()... tested on IE6/7/8, FF3, Chrome and Opera

sorry if I'm a bit late to this party.

来源：https://stackoverflow.com/questions/753514/how-do-i-dynamically-load-google-analytics-javascript