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

define(["dojo/_base/lang", "dojo/_base/config", "dojo/ready", "dojo/_base/unload",
        "dojo/_base/sniff", "dojo/request", "dojo/json", "dojo/io-query", "dojo/request/script"
], function(lang, config, ready, unload, has, request, JSON, ioQuery, script){

        var Analytics = function(){
                // summary:
                //              where we store data until we're ready to send it off.

                // the data queue;
                this._data = [];

                // id of messages for this session/page
                this._id = 1;

                // some default values
                this.sendInterval = config["sendInterval"] || 5000;
                this.inTransitRetry = config["inTransitRetry"] || 200;
                this.dataUrl = config["analyticsUrl"] || require.toUrl("dojox/analytics/logger/dojoxAnalytics.php");
                this.sendMethod = config["sendMethod"] || "xhrPost";
                this.maxRequestSize = has("ie") ? 2000 : config["maxRequestSize"] || 4000;

                // while we can go ahead and being logging as soon as this constructor is completed
                // we're not going to schedule pushing data to the server until after the page
                // has completed loading
                ready(this, "schedulePusher");
                unload.addOnUnload(this, function(){
                        this.pushData();
                });
        };

        lang.extend(Analytics, {
                schedulePusher: function(/* Int */interval){
                        // summary:
                        //              Schedule the data pushing routines to happen in interval ms
                        setTimeout(lang.hitch(this, "checkData"), interval || this.sendInterval);
                },

                addData: function(dataType, data){
                        // summary:
                        //              add data to the queue. Will be pusshed to the server on the next
                        //              data push

                        if(arguments.length > 2){
                                // FIXME: var c = dojo._toArray(arguments) ?
                                data = Array.prototype.slice.call(arguments,1);
                        }

                        this._data.push({ plugin: dataType, data: data });
                },

                checkData: function(){
                        // summary:
                        //              TODOC?
                        if(this._inTransit){
                                this.schedulePusher(this.inTransitRetry);
                                return;
                        }

                        if(this.pushData()){ return; }
                        this.schedulePusher();
                },

                pushData: function(){
                        // summary:
                        //              pushes data to the server if any exists.  If a push is done, return
                        //              the deferred after hooking up completion callbacks.  If there is no data
                        //              to be pushed, return false;
                        if(this._data.length){
                                // clear the queue
                                this._inTransit = this._data;
                                this._data = [];
                                var promise;
                                switch(this.sendMethod){
                                        case "script":
                                                promise = script.get(this.getQueryPacket(), {
                                                        preventCache: 1,
                                                        callbackParamName: "callback"
                                                });
                                                break;
                                        case "xhrPost":
                                        default:
                                                promise = request.post(this.dataUrl, {
                                                        data:{
                                                                id: this._id++,
                                                                data: JSON.stringify(this._inTransit)
                                                        }
                                                });
                                                break;
                                }
                                promise.then(lang.hitch(this, "onPushComplete"));
                                return promise;
                        }
                        return false;
                },

                getQueryPacket: function(){
                        // TODOC
                        while(true){
                                var content = {
                                        id: this._id++,
                                        data: JSON.stringify(this._inTransit)
                                };

                                // FIXME would like a much better way to get the query down to length
                                var query = this.dataUrl + '?' + ioQuery.objectToQuery(content);
                                if(query.length > this.maxRequestSize){
                                        this._data.unshift(this._inTransit.pop());
                                        this._split = 1;
                                }else{
                                        return query;
                                }
                        }
                },

                onPushComplete: function(results){
                        // summary:
                        //              If our data push was successfully, remove the _inTransit data and schedule the next
                        //              parser run.
                        if(this._inTransit){
                                delete this._inTransit;
                        }

                        if(this._data.length > 0){
                                this.schedulePusher(this.inTransitRetry);
                        }else{
                                this.schedulePusher();
                        }
                }
        });

        // create the analytics singleton
        return lang.setObject("dojox.analytics",new Analytics());
});