yuiloader-debug.js

这是YUI的源码及相关示例。里面有很多很炫的Javascript效果。

            // them asynchronously. 
            if (q.type === "script" && ua.webkit && ua.webkit < 420 && 
                    !q.finalpass && !q.varName) {
                // Add another script node.  This does not guarantee that the
                // scripts will execute in order, but it does appear to fix the
                // problem on fast connections more effectively than using an
                // arbitrary timeout.  It is possible that the browser does
                // block subsequent script execution in this case for a limited
                // time.
                var extra = _scriptNode(null, q.win, q.charset);
                extra.innerHTML='YAHOO.util.Get._finalize("' + id + '");';
                q.nodes.push(extra); h.appendChild(extra);

            } else {
                _finish(id);
            }

            return;
        } 


        var url = q.url[0];

        // if the url is undefined, this is probably a trailing comma problem in IE
        if (!url) {
            q.url.shift(); 
            return _next(id);
        }


        if (q.timeout) {
            // Y.log('create timer');
            q.timer = lang.later(q.timeout, q, _timeout, id);
        }

        if (q.type === "script") {
            n = _scriptNode(url, w, q.charset);
        } else {
            n = _linkNode(url, w, q.charset);
        }

        // track this node's load progress
        _track(q.type, n, id, url, w, q.url.length);

        // add the node to the queue so we can return it to the user supplied callback
        q.nodes.push(n);

        // add it to the head or insert it before 'insertBefore'
        if (q.insertBefore) {
            var s = _get(q.insertBefore, id);
            if (s) {
                s.parentNode.insertBefore(n, s);
            }
        } else {
            h.appendChild(n);
        }
        

        // FireFox does not support the onload event for link nodes, so there is
        // no way to make the css requests synchronous. This means that the css 
        // rules in multiple files could be applied out of order in this browser
        // if a later request returns before an earlier one.  Safari too.
        if ((ua.webkit || ua.gecko) && q.type === "css") {
            _next(id, url);
        }
    };

    /**
     * Removes processed queues and corresponding nodes
     * @method _autoPurge
     * @private
     */
    var _autoPurge = function() {

        if (purging) {
            return;
        }

        purging = true;
        for (var i in queues) {
            var q = queues[i];
            if (q.autopurge && q.finished) {
                _purge(q.tId);
                delete queues[i];
            }
        }

        purging = false;
    };

    /**
     * Removes the nodes for the specified queue
     * @method _purge
     * @private
     */
    var _purge = function(tId) {
        var q=queues[tId];
        if (q) {
            var n=q.nodes, l=n.length, d=q.win.document, 
                h=d.getElementsByTagName("head")[0];

            if (q.insertBefore) {
                var s = _get(q.insertBefore, tId);
                if (s) {
                    h = s.parentNode;
                }
            }

            for (var i=0; i<l; i=i+1) {
                h.removeChild(n[i]);
            }

            q.nodes = [];
        }
    };

    /**
     * Saves the state for the request and begins loading
     * the requested urls
     * @method queue
     * @param type {string} the type of node to insert
     * @param url {string} the url to load
     * @param opts the hash of options for this request
     * @private
     */
    var _queue = function(type, url, opts) {

        var id = "q" + (qidx++);
        opts = opts || {};

        if (qidx % YAHOO.util.Get.PURGE_THRESH === 0) {
            _autoPurge();
        }

        queues[id] = lang.merge(opts, {
            tId: id,
            type: type,
            url: url,
            finished: false,
            aborted: false,
            nodes: []
        });

        var q = queues[id];
        q.win = q.win || window;
        q.scope = q.scope || q.win;
        q.autopurge = ("autopurge" in q) ? q.autopurge : 
                      (type === "script") ? true : false;

        lang.later(0, q, _next, id);

        return {
            tId: id
        };
    };

    /**
     * Detects when a node has been loaded.  In the case of
     * script nodes, this does not guarantee that contained
     * script is ready to use.
     * @method _track
     * @param type {string} the type of node to track
     * @param n {HTMLElement} the node to track
     * @param id {string} the id of the request
     * @param url {string} the url that is being loaded
     * @param win {Window} the targeted window
     * @param qlength the number of remaining items in the queue,
     * including this one
     * @param trackfn {Function} function to execute when finished
     * the default is _next
     * @private
     */
    var _track = function(type, n, id, url, win, qlength, trackfn) {
        var f = trackfn || _next;

        // IE supports the readystatechange event for script and css nodes
        if (ua.ie) {
            n.onreadystatechange = function() {
                var rs = this.readyState;
                if ("loaded" === rs || "complete" === rs) {
                    n.onreadystatechange = null;
                    f(id, url);
                }
            };

        // webkit prior to 3.x is problemmatic
        } else if (ua.webkit) {

            if (type === "script") {

                // Safari 3.x supports the load event for script nodes (DOM2)
                if (ua.webkit >= 420) {

                    n.addEventListener("load", function() {
                        f(id, url);
                    });

                // Nothing can be done with Safari < 3.x except to pause and hope
                // for the best, particularly after last script is inserted. The
                // scripts will always execute in the order they arrive, not
                // necessarily the order in which they were inserted.  To support
                // script nodes with complete reliability in these browsers, script
                // nodes either need to invoke a function in the window once they
                // are loaded or the implementer needs to provide a well-known
                // property that the utility can poll for.
                } else {
                    // Poll for the existence of the named variable, if it
                    // was supplied.
                    var q = queues[id];
                    if (q.varName) {
                        var freq=YAHOO.util.Get.POLL_FREQ;
                        q.maxattempts = YAHOO.util.Get.TIMEOUT/freq;
                        q.attempts = 0;
                        q._cache = q.varName[0].split(".");
                        q.timer = lang.later(freq, q, function(o) {
                            var a=this._cache, l=a.length, w=this.win, i;
                            for (i=0; i<l; i=i+1) {
                                w = w[a[i]];
                                if (!w) {
                                    // if we have exausted our attempts, give up
                                    this.attempts++;
                                    if (this.attempts++ > this.maxattempts) {
                                        var msg = "Over retry limit, giving up";
                                        q.timer.cancel();
                                        _fail(id, msg);
                                    } else {
                                    }
                                    return;
                                }
                            }
                            

                            q.timer.cancel();
                            f(id, url);

                        }, null, true);
                    } else {
                        lang.later(YAHOO.util.Get.POLL_FREQ, null, f, [id, url]);
                    }
                }
            } 

        // FireFox and Opera support onload (but not DOM2 in FF) handlers for
        // script nodes.  Opera, but not FF, supports the onload event for link
        // nodes.
        } else { 
            n.onload = function() {
                f(id, url);
            };
        }
    };

    return {

        /**
         * The default poll freqency in ms, when needed
         * @property POLL_FREQ
         * @static
         * @type int
         * @default 10
         */
        POLL_FREQ: 10,

        /**
         * The number of request required before an automatic purge.
         * property PURGE_THRESH
         * @static
         * @type int
         * @default 20
         */
        PURGE_THRESH: 20,

        /**
         * The length time to poll for varName when loading a script in
         * Safari 2.x before the transaction fails.
         * property TIMEOUT
         * @static
         * @type int
         * @default 2000
         */
        TIMEOUT: 2000,
        
        /**
         * Called by the the helper for detecting script load in Safari
         * @method _finalize
         * @param id {string} the transaction id
         * @private
         */
        _finalize: function(id) {
            lang.later(0, null, _finish, id);
        },

        /**
         * Abort a transaction
         * @method abort
         * @param {string|object} either the tId or the object returned from
         * script() or css()
         */
        abort: function(o) {
            var id = (lang.isString(o)) ? o : o.tId;
            var q = queues[id];
            if (q) {
                q.aborted = true;
            }
        }, 

        /**
         * Fetches and inserts one or more script nodes into the head
         * of the current document or the document in a specified window.
         *
         * @method script
         * @static
         * @param url {string|string[]} the url or urls to the script(s)
         * @param opts {object} Options: 
         * <dl>
         * <dt>onSuccess</dt>
         * <dd>
         * callback to execute when the script(s) are finished loading
         * The callback receives an object back with the following
         * data:
         * <dl>
         * <dt>win</dt>
         * <dd>the window the script(s) were inserted into</dd>
         * <dt>data</dt>
         * <dd>the data object passed in when the request was made</dd>
         * <dt>nodes</dt>
         * <dd>An array containing references to the nodes that were
         * inserted</dd>
         * <dt>purge</dt>
         * <dd>A function that, when executed, will remove the nodes
         * that were inserted</dd>
         * <dt>
         * </dl>
         * </dd>
         * <dt>onFailure</dt>
         * <dd>
         * callback to execute when the script load operation fails
         * The callback receives an object back with the following
         * data:
         * <dl>
         * <dt>win</dt>
         * <dd>the window the script(s) were inserted into</dd>
         * <dt>data</dt>
         * <dd>the data object passed in when the request was made</dd>
         * <dt>nodes</dt>
         * <dd>An array containing references to the nodes that were
         * inserted successfully</dd>
         * <dt>purge</dt>
         * <dd>A function that, when executed, will remove any nodes
         * that were inserted</dd>
         * <dt>
         * </dl>
         * </dd>
         * <dt>onTimeout</dt>
         * <dd>
         * callback to execute when a timeout occurs.
         * The callback receives an object back with the following
         * data:
         * <dl>
         * <dt>win</dt>
         * <dd>the window the script(s) were inserted into</dd>
         * <dt>data</dt>
         * <dd>the data object passed in when the request was made</dd>
         * <dt>nodes</dt>
         * <dd>An array containing references to the nodes that were
         * inserted</dd>
         * <dt>purge</dt>
         * <dd>A function that, when executed, will remove the nodes
         * that were inserted</dd>
         * <dt>
         * </dl>
         * </dd>
         * <dt>scope</dt>
         * <dd>the execution context for the callbacks</dd>
         * <dt>win</dt>
         * <dd>a window other than the one the utility occupies</dd>
         * <dt>autopurge</dt>
         * <dd>
         * setting to true will let the utilities cleanup routine purge 
         * the script once loaded
         * </dd>
         * <dt>data</dt>
         * <dd>
         * data that is supplied to the callback when the script(s) are
         * loaded.
         * </dd>
         * <dt>varName</dt>
         * <dd>
         * variable that should be available when a script is finished
         * loading.  Used to help Safari 2.x and below with script load 
         * detection.  The type of this property should match what was
         * passed into the url parameter: if loading a single url, a
         * string can be supplied.  If loading multiple scripts, you
         * must supply an array that contains the variable name for
         * each script.
         * </dd>
         * <dt>insertBefore</dt>
         * <dd>node or node id that will become the new node's nextSibling</dd>
         * </dl>
         * <dt>charset</dt>
         * <dd>Node charset, default utf-8</dd>
         * <dt>timeout</dt>
         * <dd>Number of milliseconds to wait before aborting and firing the timeout event</dd>
         * <pre>
         * // assumes yahoo, dom, and event are already on the page
         * &nbsp;&nbsp;YAHOO.util.Get.script(
         * &nbsp;&nbsp;["http://yui.yahooapis.com/2.3.1/build/dragdrop/dragdrop-min.js",