+/*
+Copyright (c) 2009, Yahoo! Inc. All rights reserved.
+Code licensed under the BSD License:
+http://developer.yahoo.net/yui/license.txt
+version: 2.7.0
+*/
+/**
+ * Provides a mechanism to fetch remote resources and
+ * insert them into a document
+ * @module get
+ * @requires yahoo
+ */
+
+/**
+ * Fetches and inserts one or more script or link nodes into the document
+ * @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,
+
+ // ridx=0,
+
+ // sandboxFrame=null,
+
+ /**
+ * interal property used to prevent multiple simultaneous purge
+ * processes
+ * @property purging
+ * @type boolean
+ * @private
+ */
+ purging=false,
+
+ ua=YAHOO.env.ua,
+
+ lang=YAHOO.lang;
+
+ /**
+ * 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
+ */
+ var _node = function(type, attr, win) {
+ var w = win || window, d=w.document, n=d.createElement(type);
+
+ for (var i in attr) {
+ if (attr[i] && YAHOO.lang.hasOwnProperty(attr, 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
+ */
+ var _linkNode = function(url, win, charset) {
+ var c = charset || "utf-8";
+ return _node("link", {
+ "id": "yui__dyn_" + (nidx++),
+ "type": "text/css",
+ "charset": c,
+ "rel": "stylesheet",
+ "href": url
+ }, 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
+ */
+ var _scriptNode = function(url, win, charset) {
+ var c = charset || "utf-8";
+ return _node("script", {
+ "id": "yui__dyn_" + (nidx++),
+ "type": "text/javascript",
+ "charset": c,
+ "src": url
+ }, win);
+ };
+
+ /**
+ * Returns the data payload for callback functions
+ * @method _returnData
+ * @private
+ */
+ var _returnData = function(q, msg) {
+ return {
+ tId: q.tId,
+ win: q.win,
+ data: q.data,
+ nodes: q.nodes,
+ msg: msg,
+ purge: function() {
+ _purge(this.tId);
+ }
+ };
+ };
+
+ var _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 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
+ */
+ var _fail = function(id, msg) {
+ var q = queues[id];
+ // execute failure callback
+ if (q.onFailure) {
+ var sc=q.scope || q.win;
+ q.onFailure.call(sc, _returnData(q, msg));
+ }
+ };
+
+ /**
+ * The request is complete, so executing the requester's callback
+ * @method _finish
+ * @param id {string} the id of the request
+ * @private
+ */
+ var _finish = function(id) {
+ var q = queues[id];
+ q.finished = true;
+
+ if (q.aborted) {
+ var msg = "transaction " + id + " was aborted";
+ _fail(id, msg);
+ return;
+ }
+
+ // execute success callback
+ if (q.onSuccess) {
+ var sc=q.scope || q.win;
+ q.onSuccess.call(sc, _returnData(q));
+ }
+ };
+
+ /**
+ * Timeout detected
+ * @method _timeout
+ * @param id {string} the id of the request
+ * @private
+ */
+ var _timeout = function(id) {
+ var q = queues[id];
+ if (q.onTimeout) {
+ var sc=q.scope || q;
+ q.onTimeout.call(sc, _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
+ */
+ var _next = function(id, loaded) {
+ var q = queues[id];
+
+ if (q.timer) {
+ // Y.log('cancel timer');
+ q.timer.cancel();
+ }
+
+ if (q.aborted) {
+ var 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;
+ }
+ }
+
+ var w=q.win, d=w.document, h=d.getElementsByTagName("head")[0], n;
+
+ 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.
+ 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
+ * YAHOO.util.Get.script(
+ * ["http://yui.yahooapis.com/2.3.1/build/dragdrop/dragdrop-min.js",
+ * "http://yui.yahooapis.com/2.3.1/build/animation/animation-min.js"], {
+ * onSuccess: function(o) {
+ * 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) {
+ * },
+ * 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, default utf-8</dd>
+ * </dl>
+ * <pre>
+ * YAHOO.util.Get.css("http://yui.yahooapis.com/2.3.1/build/menu/assets/skins/sam/menu.css");
+ * </pre>
+ * <pre>
+ * YAHOO.util.Get.css(["http://yui.yahooapis.com/2.3.1/build/menu/assets/skins/sam/menu.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: "2.7.0", build: "1799"});