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YUI.add('yui2-get', function(Y) {

    var YAHOO    = Y.YUI2;

    /*

Copyright (c) 2011, Yahoo! Inc. All rights reserved.

Code licensed under the BSD License:

http://developer.yahoo.com/yui/license.html

version: 2.9.0

*/

/**

 * Provides a mechanism to fetch remote resources and

 * insert them into a document

 * This utility can fetch JavaScript and CSS files, inserting script

 * tags for script and link tags for CSS.  Note, this

 * is done via the normal browser mechanisms for inserting

 * these resources and making the content available to

 * code that would access it.  Be careful when retreiving

 * remote resources.  Only use this utility to fetch

 * files from sites you trust.

 *

 * @module get

 * @requires yahoo

 */

/**

 * Fetches and inserts one or more script or link nodes into the document.

 * This utility can fetch JavaScript and CSS files, inserting script

 * tags for script and link tags for CSS.  Note, this

 * is done via the normal browser mechanisms for inserting

 * these resources and making the content available to

 * code that would access it.  Be careful when retreiving

 * remote resources.  Only use this utility to fetch

 * files from sites you trust.

 *

 * @namespace YAHOO.util

 * @class YAHOO.util.Get

 */

YAHOO.util.Get = function() {

    /**

     * hash of queues to manage multiple requests

     * @property queues

     * @private

     */

    var queues={},

    /**

     * queue index used to generate transaction ids

     * @property qidx

     * @type int

     * @private

     */

        qidx=0,

    /**

     * node index used to generate unique node ids

     * @property nidx

     * @type int

     * @private

     */

        nidx=0,

    /**

     * interal property used to prevent multiple simultaneous purge

     * processes

     * @property purging

     * @type boolean

     * @private

     */

        _purging=false,

        ua=YAHOO.env.ua,

        lang=YAHOO.lang,

    _fail,

    _purge,

    _track,

    /**

     * Generates an HTML element, this is not appended to a document

     * @method _node

     * @param type {string} the type of element

     * @param attr {string} the attributes

     * @param win {Window} optional window to create the element in

     * @return {HTMLElement} the generated node

     * @private

     */

    _node = function(type, attr, win) {

        var w = win || window, d=w.document, n=d.createElement(type), i;

        for (i in attr) {

            if (attr.hasOwnProperty(i)) {

                n.setAttribute(i, attr[i]);

            }

        }

        return n;

    },

    /**

     * Generates a link node

     * @method _linkNode

     * @param url {string} the url for the css file

     * @param win {Window} optional window to create the node in

     * @return {HTMLElement} the generated node

     * @private

     */

    _linkNode = function(url, win, attributes) {

        var o = {

            id:   "yui__dyn_" + (nidx++),

            type: "text/css",

            rel:  "stylesheet",

            href: url

        };

        if (attributes) {

            lang.augmentObject(o, attributes);

        }

        return _node("link", o, win);

    },

    /**

     * Generates a script node

     * @method _scriptNode

     * @param url {string} the url for the script file

     * @param win {Window} optional window to create the node in

     * @return {HTMLElement} the generated node

     * @private

     */

    _scriptNode = function(url, win, attributes) {

        var o = {

            id:   "yui__dyn_" + (nidx++),

            type: "text/javascript",

            src:  url

        };

        if (attributes) {

            lang.augmentObject(o, attributes);

        }

        return _node("script", o, win);

    },

    /**

     * Returns the data payload for callback functions

     * @method _returnData

     * @private

     */

    _returnData = function(q, msg) {

        return {

                tId: q.tId,

                win: q.win,

                data: q.data,

                nodes: q.nodes,

                msg: msg,

                purge: function() {

                    _purge(this.tId);

                }

            };

    },

    _get = function(nId, tId) {

        var q = queues[tId],

            n = (lang.isString(nId)) ? q.win.document.getElementById(nId) : nId;

        if (!n) {

            _fail(tId, "target node not found: " + nId);

        }

        return n;

    },

    /**

     * The request is complete, so executing the requester's callback

     * @method _finish

     * @param id {string} the id of the request

     * @private

     */

    _finish = function(id) {

        YAHOO.log("Finishing transaction " + id);

        var q = queues[id], msg, context;

        q.finished = true;

        if (q.aborted) {

            msg = "transaction " + id + " was aborted";

            _fail(id, msg);

            return;

        }

        // execute success callback

        if (q.onSuccess) {

            context = q.scope || q.win;

            q.onSuccess.call(context, _returnData(q));

        }

    },

    /**

     * Timeout detected

     * @method _timeout

     * @param id {string} the id of the request

     * @private

     */

    _timeout = function(id) {

        YAHOO.log("Timeout " + id, "info", "get");

        var q = queues[id], context;

        if (q.onTimeout) {

            context = q.scope || q;

            q.onTimeout.call(context, _returnData(q));

        }

    },

    /**

     * Loads the next item for a given request

     * @method _next

     * @param id {string} the id of the request

     * @param loaded {string} the url that was just loaded, if any

     * @private

     */

    _next = function(id, loaded) {

        YAHOO.log("_next: " + id + ", loaded: " + loaded, "info", "Get");

        var q = queues[id], w=q.win, d=w.document, h=d.getElementsByTagName("head")[0],

            n, msg, url, s, extra;

        if (q.timer) {

            // Y.log('cancel timer');

            q.timer.cancel();

        }

        if (q.aborted) {

            msg = "transaction " + id + " was aborted";

            _fail(id, msg);

            return;

        }

        if (loaded) {

            q.url.shift();

            if (q.varName) {

                q.varName.shift();

            }

        } else {

            // This is the first pass: make sure the url is an array

            q.url = (lang.isString(q.url)) ? [q.url] : q.url;

            if (q.varName) {

                q.varName = (lang.isString(q.varName)) ? [q.varName] : q.varName;

            }

        }

        if (q.url.length === 0) {

            // Safari 2.x workaround - There is no way to know when

            // a script is ready in versions of Safari prior to 3.x.

            // Adding an extra node reduces the problem, but doesn't

            // eliminate it completely because the browser executes

            // 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.

                extra = _scriptNode(null, q.win, q.attributes);

                extra.innerHTML='YAHOO.util.Get._finalize("' + id + '");';

                q.nodes.push(extra); h.appendChild(extra);

            } else {

                _finish(id);

            }

            return;

        }

        url = q.url[0];

        // if the url is undefined, this is probably a trailing comma problem in IE

        if (!url) {

            q.url.shift();

            YAHOO.log('skipping empty url');

            return _next(id);

        }

        YAHOO.log("attempting to load " + url, "info", "Get");

        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.attributes);

        } else {

            n = _linkNode(url, w, q.attributes);

        }

        // 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) {

            s = _get(q.insertBefore, id);

            if (s) {

                s.parentNode.insertBefore(n, s);

            }

        } else {

            h.appendChild(n);

        }

        YAHOO.log("Appending node: " + url, "info", "Get");

        // 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

     */

    _autoPurge = function() {

        if (_purging) {

            return;

        }

        _purging = true;

        var i, q;

        for (i in queues) {

            if (queues.hasOwnProperty(i)) {

                q = queues[i];

                if (q.autopurge && q.finished) {

                    _purge(q.tId);

                    delete queues[i];

                }

            }

        }

        _purging = false;

    },

    /**

     * 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

     */

    _queue = function(type, url, opts) {

        var id = "q" + (qidx++), q;

        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: []

        });

        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;

        q.attributes = q.attributes || {};

        q.attributes.charset = opts.charset || q.attributes.charset || 'utf-8';

        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

     */

    _track = function(type, n, id, url, win, qlength, trackfn) {

        var f = trackfn || _next, rs, q, a, freq, w, l, i, msg;

        // IE supports the readystatechange event for script and css nodes

        if (ua.ie) {

            n.onreadystatechange = function() {

                rs = this.readyState;

                if ("loaded" === rs || "complete" === rs) {

                    YAHOO.log(id + " onload " + url, "info", "Get");

                    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() {

                        YAHOO.log(id + " DOM2 onload " + url, "info", "Get");

                        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.

                    q = queues[id];

                    if (q.varName) {

                        freq = YAHOO.util.Get.POLL_FREQ;

                        YAHOO.log("Polling for " + q.varName[0]);

                        q.maxattempts = YAHOO.util.Get.TIMEOUT/freq;

                        q.attempts = 0;

                        q._cache = q.varName[0].split(".");

                        q.timer = lang.later(freq, q, function(o) {

                            a = this._cache;

                            l = a.length;

                            w = this.win;

                            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) {

                                        msg = "Over retry limit, giving up";

                                        q.timer.cancel();

                                        _fail(id, msg);

                                    } else {

                                        YAHOO.log(a[i] + " failed, retrying");

                                    }

                                    return;

                                }

                            }

                            YAHOO.log("Safari poll complete");

                            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() {

                YAHOO.log(id + " onload " + url, "info", "Get");

                f(id, url);

            };

        }

    };

    /*

     * The request failed, execute fail handler with whatever

     * was accomplished.  There isn't a failure case at the

     * moment unless you count aborted transactions

     * @method _fail

     * @param id {string} the id of the request

     * @private

     */

    _fail = function(id, msg) {

        YAHOO.log("get failure: " + msg, "warn", "Get");

        var q = queues[id], context;

        // execute failure callback

        if (q.onFailure) {

            context = q.scope || q.win;

            q.onFailure.call(context, _returnData(q, msg));

        }

    };

    /**

     * Removes the nodes for the specified queue

     * @method _purge

     * @private

     */

    _purge = function(tId) {

        if (queues[tId]) {

            var q     = queues[tId],

                nodes = q.nodes,

                l     = nodes.length,

                d     = q.win.document,

                h     = d.getElementsByTagName("head")[0],

                sib, i, node, attr;

            if (q.insertBefore) {

                sib = _get(q.insertBefore, tId);

                if (sib) {

                    h = sib.parentNode;

                }

            }

            for (i=0; i<l; i=i+1) {

                node = nodes[i];

                if (node.clearAttributes) {

                    node.clearAttributes();

                } else {

                    for (attr in node) {

                        if (node.hasOwnProperty(attr)) {

                            delete node[attr];

                        }

                    }

                }

                h.removeChild(node);

            }

            q.nodes = [];

        }

    };

    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) {

            YAHOO.log(id + " finalized ", "info", "Get");

            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,

                q = queues[id];

            if (q) {

                YAHOO.log("Aborting " + id, "info", "Get");

                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, deprecated, use 'attributes'</dd>

         * <dt>attributes</dt>

         * <dd>A hash of attributes to apply to dynamic nodes.</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

         *   YAHOO.util.Get.script(

         *   ["http://yui.yahooapis.com/2.7.0/build/dragdrop/dragdrop-min.js",

         *    "http://yui.yahooapis.com/2.7.0/build/animation/animation-min.js"], {

         *     onSuccess: function(o) {

         *       YAHOO.log(o.data); // foo

         *       new YAHOO.util.DDProxy("dd1"); // also new o.reference("dd1"); would work

         *       this.log("won't cause error because YAHOO is the scope");

         *       this.log(o.nodes.length === 2) // true

         *       // o.purge(); // optionally remove the script nodes immediately

         *     },

         *     onFailure: function(o) {

         *       YAHOO.log("transaction failed");

         *     },

         *     data: "foo",

         *     timeout: 10000, // 10 second timeout

         *     scope: YAHOO,

         *     // win: otherframe // target another window/frame

         *     autopurge: true // allow the utility to choose when to remove the nodes

         *   });

         * </pre>

         * @return {tId: string} an object containing info about the transaction

         */

        script: function(url, opts) { return _queue("script", url, opts); },

        /**

         * Fetches and inserts one or more css link nodes into the

         * head of the current document or the document in a specified

         * window.

         * @method css

         * @static

         * @param url {string} the url or urls to the css file(s)

         * @param opts Options:

         * <dl>

         * <dt>onSuccess</dt>

         * <dd>

         * callback to execute when the css file(s) are finished loading

         * The callback receives an object back with the following

         * data:

         * <dl>win</dl>

         * <dd>the window the link nodes(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>data</dt>

         * <dd>

         * data that is supplied to the callbacks when the nodes(s) are

         * loaded.

         * </dd>

         * <dt>insertBefore</dt>

         * <dd>node or node id that will become the new node's nextSibling</dd>

         * <dt>charset</dt>

         * <dd>Node charset, deprecated, use 'attributes'</dd>

         * <dt>attributes</dt>

         * <dd>A hash of attributes to apply to dynamic nodes.</dd>

         * </dl>

         * <pre>

         *      YAHOO.util.Get.css("http://yui.yahooapis.com/2.7.0/build/menu/assets/skins/sam/menu.css");

         * </pre>

         * <pre>

         *      YAHOO.util.Get.css(["http://yui.yahooapis.com/2.7.0/build/menu/assets/skins/sam/menu.css",

         *                          "http://yui.yahooapis.com/2.7.0/build/logger/assets/skins/sam/logger.css"]);

         * </pre>

         * @return {tId: string} an object containing info about the transaction

         */

        css: function(url, opts) {

            return _queue("css", url, opts);

        }

    };

}();

YAHOO.register("get", YAHOO.util.Get, {version: "2.9.0", build: "2800"});

}, '2.9.0' ,{"requires": ["yui2-yahoo"]});