--- /dev/null
+/*
+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
+*/
+/**
+ * The Browser History Manager provides the ability to use the back/forward
+ * navigation buttons in a DHTML application. It also allows a DHTML
+ * application to be bookmarked in a specific state.
+ *
+ * This library requires the following static markup:
+ *
+ * <iframe id="yui-history-iframe" src="path-to-real-asset-in-same-domain"></iframe>
+ * <input id="yui-history-field" type="hidden">
+ *
+ * @module history
+ * @requires yahoo,event
+ * @namespace YAHOO.util
+ * @title Browser History Manager
+ */
+
+/**
+ * The History class provides the ability to use the back/forward navigation
+ * buttons in a DHTML application. It also allows a DHTML application to
+ * be bookmarked in a specific state.
+ *
+ * @class History
+ * @constructor
+ */
+YAHOO.util.History = (function () {
+
+ /**
+ * Our hidden IFrame used to store the browsing history.
+ *
+ * @property _histFrame
+ * @type HTMLIFrameElement
+ * @default null
+ * @private
+ */
+ var _histFrame = null;
+
+ /**
+ * INPUT field (with type="hidden" or type="text") or TEXTAREA.
+ * This field keeps the value of the initial state, current state
+ * the list of all states across pages within a single browser session.
+ *
+ * @property _stateField
+ * @type HTMLInputElement|HTMLTextAreaElement
+ * @default null
+ * @private
+ */
+ var _stateField = null;
+
+ /**
+ * Flag used to tell whether YAHOO.util.History.initialize has been called.
+ *
+ * @property _initialized
+ * @type boolean
+ * @default false
+ * @private
+ */
+ var _initialized = false;
+
+ /**
+ * List of registered modules.
+ *
+ * @property _modules
+ * @type array
+ * @default []
+ * @private
+ */
+ var _modules = [];
+
+ /**
+ * List of fully qualified states. This is used only by Safari.
+ *
+ * @property _fqstates
+ * @type array
+ * @default []
+ * @private
+ */
+ var _fqstates = [];
+
+ /**
+ * location.hash is a bit buggy on Opera. I have seen instances where
+ * navigating the history using the back/forward buttons, and hence
+ * changing the URL, would not change location.hash. That's ok, the
+ * implementation of an equivalent is trivial.
+ *
+ * @method _getHash
+ * @return {string} The hash portion of the document's location
+ * @private
+ */
+ function _getHash() {
+ var i, href;
+ href = top.location.href;
+ i = href.indexOf("#");
+ return i >= 0 ? href.substr(i + 1) : null;
+ }
+
+ /**
+ * Stores all the registered modules' initial state and current state.
+ * On Safari, we also store all the fully qualified states visited by
+ * the application within a single browser session. The storage takes
+ * place in the form field specified during initialization.
+ *
+ * @method _storeStates
+ * @private
+ */
+ function _storeStates() {
+
+ var moduleName, moduleObj, initialStates = [], currentStates = [];
+
+ for (moduleName in _modules) {
+ if (YAHOO.lang.hasOwnProperty(_modules, moduleName)) {
+ moduleObj = _modules[moduleName];
+ initialStates.push(moduleName + "=" + moduleObj.initialState);
+ currentStates.push(moduleName + "=" + moduleObj.currentState);
+ }
+ }
+
+ _stateField.value = initialStates.join("&") + "|" + currentStates.join("&");
+
+ if (YAHOO.env.ua.webkit) {
+ _stateField.value += "|" + _fqstates.join(",");
+ }
+ }
+
+ /**
+ * Sets the new currentState attribute of all modules depending on the new
+ * fully qualified state. Also notifies the modules which current state has
+ * changed.
+ *
+ * @method _handleFQStateChange
+ * @param {string} fqstate Fully qualified state
+ * @private
+ */
+ function _handleFQStateChange(fqstate) {
+
+ var i, len, moduleName, moduleObj, modules, states, tokens, currentState;
+
+ if (!fqstate) {
+ // Notifies all modules
+ for (moduleName in _modules) {
+ if (YAHOO.lang.hasOwnProperty(_modules, moduleName)) {
+ moduleObj = _modules[moduleName];
+ moduleObj.currentState = moduleObj.initialState;
+ moduleObj.onStateChange(unescape(moduleObj.currentState));
+ }
+ }
+ return;
+ }
+
+ modules = [];
+ states = fqstate.split("&");
+ for (i = 0, len = states.length; i < len; i++) {
+ tokens = states[i].split("=");
+ if (tokens.length === 2) {
+ moduleName = tokens[0];
+ currentState = tokens[1];
+ modules[moduleName] = currentState;
+ }
+ }
+
+ for (moduleName in _modules) {
+ if (YAHOO.lang.hasOwnProperty(_modules, moduleName)) {
+ moduleObj = _modules[moduleName];
+ currentState = modules[moduleName];
+ if (!currentState || moduleObj.currentState !== currentState) {
+ moduleObj.currentState = currentState || moduleObj.initialState;
+ moduleObj.onStateChange(unescape(moduleObj.currentState));
+ }
+ }
+ }
+ }
+
+ /**
+ * Update the IFrame with our new state.
+ *
+ * @method _updateIFrame
+ * @private
+ * @return {boolean} true if successful. false otherwise.
+ */
+ function _updateIFrame (fqstate) {
+
+ var html, doc;
+
+ html = '<html><body><div id="state">' + fqstate + '</div></body></html>';
+
+ try {
+ doc = _histFrame.contentWindow.document;
+ doc.open();
+ doc.write(html);
+ doc.close();
+ return true;
+ } catch (e) {
+ return false;
+ }
+ }
+
+ /**
+ * Periodically checks whether our internal IFrame is ready to be used.
+ *
+ * @method _checkIframeLoaded
+ * @private
+ */
+ function _checkIframeLoaded() {
+
+ var doc, elem, fqstate, hash;
+
+ if (!_histFrame.contentWindow || !_histFrame.contentWindow.document) {
+ // Check again in 10 msec...
+ setTimeout(_checkIframeLoaded, 10);
+ return;
+ }
+
+ // Start the thread that will have the responsibility to
+ // periodically check whether a navigate operation has been
+ // requested on the main window. This will happen when
+ // YAHOO.util.History.navigate has been called or after
+ // the user has hit the back/forward button.
+
+ doc = _histFrame.contentWindow.document;
+ elem = doc.getElementById("state");
+ // We must use innerText, and not innerHTML because our string contains
+ // the "&" character (which would end up being escaped as "&") and
+ // the string comparison would fail...
+ fqstate = elem ? elem.innerText : null;
+
+ hash = _getHash();
+
+ setInterval(function () {
+
+ var newfqstate, states, moduleName, moduleObj, newHash, historyLength;
+
+ doc = _histFrame.contentWindow.document;
+ elem = doc.getElementById("state");
+ // See my comment above about using innerText instead of innerHTML...
+ newfqstate = elem ? elem.innerText : null;
+
+ newHash = _getHash();
+
+ if (newfqstate !== fqstate) {
+
+ fqstate = newfqstate;
+ _handleFQStateChange(fqstate);
+
+ if (!fqstate) {
+ states = [];
+ for (moduleName in _modules) {
+ if (YAHOO.lang.hasOwnProperty(_modules, moduleName)) {
+ moduleObj = _modules[moduleName];
+ states.push(moduleName + "=" + moduleObj.initialState);
+ }
+ }
+ newHash = states.join("&");
+ } else {
+ newHash = fqstate;
+ }
+
+ // Allow the state to be bookmarked by setting the top window's
+ // URL fragment identifier. Note that here, we are on IE, and
+ // IE does not touch the browser history when setting the hash
+ // (unlike all the other browsers). I used to write:
+ // top.location.replace( "#" + hash );
+ // but this had a side effect when the page was not the top frame.
+ top.location.hash = newHash;
+ hash = newHash;
+
+ _storeStates();
+
+ } else if (newHash !== hash) {
+
+ // The hash has changed. The user might have clicked on a link,
+ // or modified the URL directly, or opened the same application
+ // bookmarked in a specific state using a bookmark. However, we
+ // know the hash change was not caused by a hit on the back or
+ // forward buttons, or by a call to navigate() (because it would
+ // have been handled above) We must handle these cases, which is
+ // why we also need to keep track of hash changes on IE!
+
+ // Note that IE6 has some major issues with this kind of user
+ // interaction (the history stack gets completely messed up)
+ // but it seems to work fine on IE7.
+
+ hash = newHash;
+
+ // Now, store a new history entry. The following will cause the
+ // code above to execute, doing all the dirty work for us...
+ _updateIFrame(newHash);
+ }
+
+ }, 50);
+
+ _initialized = true;
+ YAHOO.util.History.onLoadEvent.fire();
+ }
+
+ /**
+ * Finish up the initialization of the Browser History Manager.
+ *
+ * @method _initialize
+ * @private
+ */
+ function _initialize() {
+
+ var i, len, parts, tokens, moduleName, moduleObj, initialStates, initialState, currentStates, currentState, counter, hash;
+
+ // Decode the content of our storage field...
+ parts = _stateField.value.split("|");
+
+ if (parts.length > 1) {
+
+ initialStates = parts[0].split("&");
+ for (i = 0, len = initialStates.length; i < len; i++) {
+ tokens = initialStates[i].split("=");
+ if (tokens.length === 2) {
+ moduleName = tokens[0];
+ initialState = tokens[1];
+ moduleObj = _modules[moduleName];
+ if (moduleObj) {
+ moduleObj.initialState = initialState;
+ }
+ }
+ }
+
+ currentStates = parts[1].split("&");
+ for (i = 0, len = currentStates.length; i < len; i++) {
+ tokens = currentStates[i].split("=");
+ if (tokens.length >= 2) {
+ moduleName = tokens[0];
+ currentState = tokens[1];
+ moduleObj = _modules[moduleName];
+ if (moduleObj) {
+ moduleObj.currentState = currentState;
+ }
+ }
+ }
+ }
+
+ if (parts.length > 2) {
+ _fqstates = parts[2].split(",");
+ }
+
+ if (YAHOO.env.ua.ie) {
+
+ if (typeof document.documentMode === "undefined" || document.documentMode < 8) {
+
+ // IE < 8 or IE8 in quirks mode or IE7 standards mode
+ _checkIframeLoaded();
+
+ } else {
+
+ // IE8 in IE8 standards mode
+ YAHOO.util.Event.on(top, "hashchange",
+ function () {
+ var hash = _getHash();
+ _handleFQStateChange(hash);
+ _storeStates();
+ });
+
+ _initialized = true;
+ YAHOO.util.History.onLoadEvent.fire();
+
+ }
+
+ } else {
+
+ // Start the thread that will have the responsibility to
+ // periodically check whether a navigate operation has been
+ // requested on the main window. This will happen when
+ // YAHOO.util.History.navigate has been called or after
+ // the user has hit the back/forward button.
+
+ // On Safari 1.x and 2.0, the only way to catch a back/forward
+ // operation is to watch history.length... We basically exploit
+ // what I consider to be a bug (history.length is not supposed
+ // to change when going back/forward in the history...) This is
+ // why, in the following thread, we first compare the hash,
+ // because the hash thing will be fixed in the next major
+ // version of Safari. So even if they fix the history.length
+ // bug, all this will still work!
+ counter = history.length;
+
+ // On Gecko and Opera, we just need to watch the hash...
+ hash = _getHash();
+
+ setInterval(function () {
+
+ var state, newHash, newCounter;
+
+ newHash = _getHash();
+ newCounter = history.length;
+ if (newHash !== hash) {
+ hash = newHash;
+ counter = newCounter;
+ _handleFQStateChange(hash);
+ _storeStates();
+ } else if (newCounter !== counter && YAHOO.env.ua.webkit) {
+ hash = newHash;
+ counter = newCounter;
+ state = _fqstates[counter - 1];
+ _handleFQStateChange(state);
+ _storeStates();
+ }
+
+ }, 50);
+
+ _initialized = true;
+ YAHOO.util.History.onLoadEvent.fire();
+ }
+ }
+
+ return {
+
+ /**
+ * Fired when the Browser History Manager is ready. If you subscribe to
+ * this event after the Browser History Manager has been initialized,
+ * it will not fire. Therefore, it is recommended to use the onReady
+ * method instead.
+ *
+ * @event onLoadEvent
+ * @see onReady
+ */
+ onLoadEvent: new YAHOO.util.CustomEvent("onLoad"),
+
+ /**
+ * Executes the supplied callback when the Browser History Manager is
+ * ready. This will execute immediately if called after the Browser
+ * History Manager onLoad event has fired.
+ *
+ * @method onReady
+ * @param {function} fn what to execute when the Browser History Manager is ready.
+ * @param {object} obj an optional object to be passed back as a parameter to fn.
+ * @param {boolean|object} override If true, the obj passed in becomes fn's execution scope.
+ * @see onLoadEvent
+ */
+ onReady: function (fn, obj, override) {
+
+ if (_initialized) {
+
+ setTimeout(function () {
+ var ctx = window;
+ if (override) {
+ if (override === true) {
+ ctx = obj;
+ } else {
+ ctx = override;
+ }
+ }
+ fn.call(ctx, "onLoad", [], obj);
+ }, 0);
+
+ } else {
+
+ YAHOO.util.History.onLoadEvent.subscribe(fn, obj, override);
+
+ }
+ },
+
+ /**
+ * Registers a new module.
+ *
+ * @method register
+ * @param {string} module Non-empty string uniquely identifying the
+ * module you wish to register.
+ * @param {string} initialState The initial state of the specified
+ * module corresponding to its earliest history entry.
+ * @param {function} onStateChange Callback called when the
+ * state of the specified module has changed.
+ * @param {object} obj An arbitrary object that will be passed as a
+ * parameter to the handler.
+ * @param {boolean} override If true, the obj passed in becomes the
+ * execution scope of the listener.
+ */
+ register: function (module, initialState, onStateChange, obj, override) {
+
+ var scope, wrappedFn;
+
+ if (typeof module !== "string" || YAHOO.lang.trim(module) === "" ||
+ typeof initialState !== "string" ||
+ typeof onStateChange !== "function") {
+ throw new Error("Missing or invalid argument");
+ }
+
+ if (_modules[module]) {
+ // Here, we used to throw an exception. However, users have
+ // complained about this behavior, so we now just return.
+ return;
+ }
+
+ // Note: A module CANNOT be registered after calling
+ // YAHOO.util.History.initialize. Indeed, we set the initial state
+ // of each registered module in YAHOO.util.History.initialize.
+ // If you could register a module after initializing the Browser
+ // History Manager, you would not read the correct state using
+ // YAHOO.util.History.getCurrentState when coming back to the
+ // page using the back button.
+ if (_initialized) {
+ throw new Error("All modules must be registered before calling YAHOO.util.History.initialize");
+ }
+
+ // Make sure the strings passed in do not contain our separators "," and "|"
+ module = escape(module);
+ initialState = escape(initialState);
+
+ // If the user chooses to override the scope, we use the
+ // custom object passed in as the execution scope.
+ scope = null;
+ if (override === true) {
+ scope = obj;
+ } else {
+ scope = override;
+ }
+
+ wrappedFn = function (state) {
+ return onStateChange.call(scope, state, obj);
+ };
+
+ _modules[module] = {
+ name: module,
+ initialState: initialState,
+ currentState: initialState,
+ onStateChange: wrappedFn
+ };
+ },
+
+ /**
+ * Initializes the Browser History Manager. Call this method
+ * from a script block located right after the opening body tag.
+ *
+ * @method initialize
+ * @param {string|HTML Element} stateField <input type="hidden"> used
+ * to store application states. Must be in the static markup.
+ * @param {string|HTML Element} histFrame IFrame used to store
+ * the history (only required on Internet Explorer)
+ * @public
+ */
+ initialize: function (stateField, histFrame) {
+
+ if (_initialized) {
+ // The browser history manager has already been initialized.
+ return;
+ }
+
+ if (YAHOO.env.ua.opera && typeof history.navigationMode !== "undefined") {
+ // Disable Opera's fast back/forward navigation mode and puts
+ // it in compatible mode. This makes anchor-based history
+ // navigation work after the page has been navigated away
+ // from and re-activated, at the cost of slowing down
+ // back/forward navigation to and from that page.
+ history.navigationMode = "compatible";
+ }
+
+ if (typeof stateField === "string") {
+ stateField = document.getElementById(stateField);
+ }
+
+ if (!stateField ||
+ stateField.tagName.toUpperCase() !== "TEXTAREA" &&
+ (stateField.tagName.toUpperCase() !== "INPUT" ||
+ stateField.type !== "hidden" &&
+ stateField.type !== "text")) {
+ throw new Error("Missing or invalid argument");
+ }
+
+ _stateField = stateField;
+
+ // IE < 8 or IE8 in quirks mode or IE7 standards mode
+ if (YAHOO.env.ua.ie && (typeof document.documentMode === "undefined" || document.documentMode < 8)) {
+
+ if (typeof histFrame === "string") {
+ histFrame = document.getElementById(histFrame);
+ }
+
+ if (!histFrame || histFrame.tagName.toUpperCase() !== "IFRAME") {
+ throw new Error("Missing or invalid argument");
+ }
+
+ _histFrame = histFrame;
+ }
+
+ // Note that the event utility MUST be included inline in the page.
+ // If it gets loaded later (which you may want to do to improve the
+ // loading speed of your site), the onDOMReady event never fires,
+ // and the history library never gets fully initialized.
+ YAHOO.util.Event.onDOMReady(_initialize);
+ },
+
+ /**
+ * Call this method when you want to store a new entry in the browser's history.
+ *
+ * @method navigate
+ * @param {string} module Non-empty string representing your module.
+ * @param {string} state String representing the new state of the specified module.
+ * @return {boolean} Indicates whether the new state was successfully added to the history.
+ * @public
+ */
+ navigate: function (module, state) {
+
+ var states;
+
+ if (typeof module !== "string" || typeof state !== "string") {
+ throw new Error("Missing or invalid argument");
+ }
+
+ states = {};
+ states[module] = state;
+
+ return YAHOO.util.History.multiNavigate(states);
+ },
+
+ /**
+ * Call this method when you want to store a new entry in the browser's history.
+ *
+ * @method multiNavigate
+ * @param {object} states Associative array of module-state pairs to set simultaneously.
+ * @return {boolean} Indicates whether the new state was successfully added to the history.
+ * @public
+ */
+ multiNavigate: function (states) {
+
+ var currentStates, moduleName, moduleObj, currentState, fqstate;
+
+ if (typeof states !== "object") {
+ throw new Error("Missing or invalid argument");
+ }
+
+ if (!_initialized) {
+ throw new Error("The Browser History Manager is not initialized");
+ }
+
+ for (moduleName in states) {
+ if (!_modules[moduleName]) {
+ throw new Error("The following module has not been registered: " + moduleName);
+ }
+ }
+
+ // Generate our new full state string mod1=xxx&mod2=yyy
+ currentStates = [];
+
+ for (moduleName in _modules) {
+ if (YAHOO.lang.hasOwnProperty(_modules, moduleName)) {
+ moduleObj = _modules[moduleName];
+ if (YAHOO.lang.hasOwnProperty(states, moduleName)) {
+ currentState = states[unescape(moduleName)];
+ } else {
+ currentState = unescape(moduleObj.currentState);
+ }
+
+ // Make sure the strings passed in do not contain our separators "," and "|"
+ moduleName = escape(moduleName);
+ currentState = escape(currentState);
+
+ currentStates.push(moduleName + "=" + currentState);
+ }
+ }
+
+ fqstate = currentStates.join("&");
+
+ if (YAHOO.env.ua.ie && (typeof document.documentMode === "undefined" || document.documentMode < 8)) {
+
+ return _updateIFrame(fqstate);
+
+ } else {
+
+ // Known bug: On Safari 1.x and 2.0, if you have tab browsing
+ // enabled, Safari will show an endless loading icon in the
+ // tab. This has apparently been fixed in recent WebKit builds.
+ // One work around found by Dav Glass is to submit a form that
+ // points to the same document. This indeed works on Safari 1.x
+ // and 2.0 but creates bigger problems on WebKit. So for now,
+ // we'll consider this an acceptable bug, and hope that Apple
+ // comes out with their next version of Safari very soon.
+ top.location.hash = fqstate;
+ if (YAHOO.env.ua.webkit) {
+ // The following two lines are only useful for Safari 1.x
+ // and 2.0. Recent nightly builds of WebKit do not require
+ // that, but unfortunately, it is not easy to differentiate
+ // between the two. Once Safari 2.0 departs the A-grade
+ // list, we can remove the following two lines...
+ _fqstates[history.length] = fqstate;
+ _storeStates();
+ }
+
+ return true;
+
+ }
+ },
+
+ /**
+ * Returns the current state of the specified module.
+ *
+ * @method getCurrentState
+ * @param {string} module Non-empty string representing your module.
+ * @return {string} The current state of the specified module.
+ * @public
+ */
+ getCurrentState: function (module) {
+
+ var moduleObj;
+
+ if (typeof module !== "string") {
+ throw new Error("Missing or invalid argument");
+ }
+
+ if (!_initialized) {
+ throw new Error("The Browser History Manager is not initialized");
+ }
+
+ moduleObj = _modules[module];
+ if (!moduleObj) {
+ throw new Error("No such registered module: " + module);
+ }
+
+ return unescape(moduleObj.currentState);
+ },
+
+ /**
+ * Returns the state of a module according to the URL fragment
+ * identifier. This method is useful to initialize your modules
+ * if your application was bookmarked from a particular state.
+ *
+ * @method getBookmarkedState
+ * @param {string} module Non-empty string representing your module.
+ * @return {string} The bookmarked state of the specified module.
+ * @public
+ */
+ getBookmarkedState: function (module) {
+
+ var i, len, idx, hash, states, tokens, moduleName;
+
+ if (typeof module !== "string") {
+ throw new Error("Missing or invalid argument");
+ }
+
+ // Use location.href instead of location.hash which is already
+ // URL-decoded, which creates problems if the state value
+ // contained special characters...
+ idx = top.location.href.indexOf("#");
+ if (idx >= 0) {
+ hash = top.location.href.substr(idx + 1);
+ states = hash.split("&");
+ for (i = 0, len = states.length; i < len; i++) {
+ tokens = states[i].split("=");
+ if (tokens.length === 2) {
+ moduleName = tokens[0];
+ if (moduleName === module) {
+ return unescape(tokens[1]);
+ }
+ }
+ }
+ }
+
+ return null;
+ },
+
+ /**
+ * Returns the value of the specified query string parameter.
+ * This method is not used internally by the Browser History Manager.
+ * However, it is provided here as a helper since many applications
+ * using the Browser History Manager will want to read the value of
+ * url parameters to initialize themselves.
+ *
+ * @method getQueryStringParameter
+ * @param {string} paramName Name of the parameter we want to look up.
+ * @param {string} queryString Optional URL to look at. If not specified,
+ * this method uses the URL in the address bar.
+ * @return {string} The value of the specified parameter, or null.
+ * @public
+ */
+ getQueryStringParameter: function (paramName, url) {
+
+ var i, len, idx, queryString, params, tokens;
+
+ url = url || top.location.href;
+
+ idx = url.indexOf("?");
+ queryString = idx >= 0 ? url.substr(idx + 1) : url;
+
+ // Remove the hash if any
+ idx = queryString.lastIndexOf("#");
+ queryString = idx >= 0 ? queryString.substr(0, idx) : queryString;
+
+ params = queryString.split("&");
+
+ for (i = 0, len = params.length; i < len; i++) {
+ tokens = params[i].split("=");
+ if (tokens.length >= 2) {
+ if (tokens[0] === paramName) {
+ return unescape(tokens[1]);
+ }
+ }
+ }
+
+ return null;
+ }
+
+ };
+
+})();
+YAHOO.register("history", YAHOO.util.History, {version: "2.7.0", build: "1799"});