source: Dev/trunk/src/client/dojox/analytics/Urchin.js

define(["dojo/_base/lang", "dojo/_base/declare", "dojo/_base/window",
        "dojo/_base/config", "dojo/dom-construct"
], function(lang, declare, window, config, construct){

        /*=====
        lang.mixin(config,{
                // urchin: String
                //              Used by `dojox.analytics.Urchin` as the default UA-123456-7 account
                //              number used when being created. Alternately, you can pass an acct:""
                //              parameter to the constructor a la: new dojox.analytics.Urchin({ acct:"UA-123456-7" });
                urchin: ""
        });
        =====*/

        return declare("dojox.analytics.Urchin", null, {
                // summary:
                //              A Google-analytics helper, for post-onLoad inclusion of the tracker, and
                //              dynamic tracking during long-lived page cycles.
                // description:
                //              A small class object will allows for lazy-loading the Google Analytics API
                //              at any point during a page lifecycle. Most commonly, Google-Analytics is loaded
                //              via a synchronous script tag in the body, which causes `dojo.addOnLoad` to
                //              stall until the external API has been completely loaded. The Urchin helper
                //              will load the API on the fly, and provide a convenient API to use, wrapping
                //              Analytics for Ajaxy or single page applications.
                //
                //              The class can be instantiated two ways: Programatically, by passing an
                //              `acct:` parameter, or via Markup / dojoType and defining a djConfig
                //              parameter `urchin:`
                //
                //              IMPORTANT:
                //              This module will not work simultaneously with the core dojox.analytics
                //              package. If you need the ability to run Google Analytics AND your own local
                //              analytics system, you MUST include dojox.analytics._base BEFORE dojox.analytics.Urchin
                // example:
                //      |       // create the tracker programatically:
                //      |       var tracker = new dojox.analytics.Urchin({ acct:"UA-123456-7" });
                //
                // example:
                //      |       // define the urchin djConfig option:
                //      |       var djConfig = { urchin: "UA-123456-7" };
                //      |
                //      |       // and in markup:
                //      |       <div dojoType="dojox.analytics.Urchin"></div>
                //      |       // or code:
                //      |       new dojox.analytics.Urchin();
                //
                // example:
                //      |       // create and define all analytics with one tag.
                //      |       <div dojoType="dojox.analytics.Urchin" acct="UA-12345-67"></div>

                // acct: String
                //              your GA urchin tracker account number. Overrides `djConfig.urchin`
                acct: "",

                constructor: function(args){
                        // summary:
                        //              Initialize this Urchin instance. Immediately starts the load
                        //              sequence, so defer construction until (ideally) after onLoad and
                        //              potentially widget parsing.
                        this.tracker = null;
                        lang.mixin(this, args);
                        this.acct = this.acct || config.urchin;

                        var re = /loaded|complete/,
                                gaHost = ("https:" == window.doc.location.protocol) ? "https://ssl." : "http://www.",
                                h = window.doc.getElementsByTagName("head")[0],
                                n = construct.create('script', {
                                        src: gaHost + "google-analytics.com/ga.js"
                                }, h);

                        n.onload = n.onreadystatechange = lang.hitch(this, function(e){
                                if(e && e.type == "load" || re.test(n.readyState)){
                                        n.onload = n.onreadystatechange = null;
                                        this._gotGA();
                                        h.removeChild(n);
                                }
                        });

                },

                _gotGA: function(){
                        // summary:
                        //              initialize the tracker
                        this.tracker = _gat._getTracker(this.acct);
                        this.GAonLoad.apply(this, arguments);
                },

                GAonLoad: function(){
                        // summary:
                        //              Stub function to fire when urchin is complete
                        // description:
                        //              This function is executed when the tracker variable is
                        //              complete and initialized. The initial trackPageView (with
                        //              no arguments) is called here as well, so remeber to call
                        //              manually if overloading this method.
                        //
                        // example:
                        //              Create an Urchin tracker that will track a specific page on init
                        //              after page load (or parsing, if parseOnLoad is true)
                        //      |       dojo.addOnLoad(function(){
                        //      |               new dojox.ananlytics.Urchin({
                        //      |                       acct:"UA-12345-67",
                        //      |                       GAonLoad: function(){
                        //      |                               this.trackPageView("/custom-page");
                        //      |                       }
                        //      |               });
                        //      |       });
                        
                        this.trackPageView();
                },

                trackPageView: function(/* string */url){
                        // summary:
                        //              A public API attached to this widget instance, allowing you
                        //              Ajax-like notification of updates.
                        // url: String
                        //              A location to tell the tracker to track, eg: "/my-ajaxy-endpoint"
                        // example:
                        //              Track clicks from a container of anchors and populate a `ContentPane`
                        //      |       // 'tracker' is our `Urchin` instance, pane is the `ContentPane` ref.
                        //      |       dojo.connect(container, "onclick", function(e){
                        //      |               var ref = dojo.attr(e.target, "href");
                        //      |               tracker.trackPageView(ref);
                        //      |               pane.attr("href", ref);
                        //      |       });
                        
                        this.tracker._trackPageview.apply(this.tracker, arguments);
                }

        });
});