source: Dev/trunk/src/client/dojo/domReady.js @ 501

define(['./has'], function(has){
        var global = this,
                doc = document,
                readyStates = { 'loaded': 1, 'complete': 1 },
                fixReadyState = typeof doc.readyState != "string",
                ready = !!readyStates[doc.readyState],
                readyQ = [],
                recursiveGuard;

        function domReady(callback){
                // summary:
                //              Plugin to delay require()/define() callback from firing until the DOM has finished loading.
                readyQ.push(callback);
                if(ready){ processQ(); }
        }
        domReady.load = function(id, req, load){
                domReady(load);
        };

        // Export queue so that ready() can check if it's empty or not.
        domReady._Q = readyQ;
        domReady._onQEmpty = function(){
                // summary:
                //              Private method overridden by dojo/ready, to notify when everything in the
                //              domReady queue has been processed.  Do not use directly.
                //              Will be removed in 2.0, along with domReady._Q.
        };

        // For FF <= 3.5
        if(fixReadyState){ doc.readyState = "loading"; }

        function processQ(){
                // Calls all functions in the queue in order, unless processQ() is already running, in which case just return

                if(recursiveGuard){ return; }
                recursiveGuard = true;

                while(readyQ.length){
                        try{
                                (readyQ.shift())(doc);
                        }catch(err){
                                console.log("Error on domReady callback: " + err);
                        }
                }

                recursiveGuard = false;

                // Notification for dojo/ready.  Remove for 2.0.
                // Note that this could add more tasks to the ready queue.
                domReady._onQEmpty();
        }

        if(!ready){
                var tests = [],
                        detectReady = function(evt){
                                evt = evt || global.event;
                                if(ready || (evt.type == "readystatechange" && !readyStates[doc.readyState])){ return; }

                                // For FF <= 3.5
                                if(fixReadyState){ doc.readyState = "complete"; }

                                ready = 1;
                                processQ();
                        },
                        on = function(node, event){
                                node.addEventListener(event, detectReady, false);
                                readyQ.push(function(){ node.removeEventListener(event, detectReady, false); });
                        };

                if(!has("dom-addeventlistener")){
                        on = function(node, event){
                                event = "on" + event;
                                node.attachEvent(event, detectReady);
                                readyQ.push(function(){ node.detachEvent(event, detectReady); });
                        };

                        var div = doc.createElement("div");
                        try{
                                if(div.doScroll && global.frameElement === null){
                                        // the doScroll test is only useful if we're in the top-most frame
                                        tests.push(function(){
                                                // Derived with permission from Diego Perini's IEContentLoaded
                                                // http://javascript.nwbox.com/IEContentLoaded/
                                                try{
                                                        div.doScroll("left");
                                                        return 1;
                                                }catch(e){}
                                        });
                                }
                        }catch(e){}
                }

                on(doc, "DOMContentLoaded");
                on(global, "load");

                if("onreadystatechange" in doc){
                        on(doc, "readystatechange");
                }else if(!fixReadyState){
                        // if the ready state property exists and there's
                        // no readystatechange event, poll for the state
                        // to change
                        tests.push(function(){
                                return readyStates[doc.readyState];
                        });
                }

                if(tests.length){
                        var poller = function(){
                                if(ready){ return; }
                                var i = tests.length;
                                while(i--){
                                        if(tests[i]()){
                                                detectReady("poller");
                                                return;
                                        }
                                }
                                setTimeout(poller, 30);
                        };
                        poller();
                }
        }

        return domReady;
});