yui/docs/history.js.html

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   4         <title>API: history   history.js  (YUI Library)</title>
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   8 <body id="yahoo-com">
   9 <div id="doc3" class="yui-t2">
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  12         <h1>Yahoo! UI Library</h1>
  13         <h3>Browser History Manager&nbsp; <span class="subtitle">2.2.0</span></h3>
  14         <p>
  15         <a href="./index.html">Yahoo! UI Library</a>
  16             &gt; <a href="./module_history.html">history</a>
  17
  18                  &gt; history.js (source view)
  19             </p>
  20         </div>
  21
  22         <div id="bd">
  23                 <div id="yui-main">
  24                         <div class="yui-b">
  25
  26                     <div id="srcout">
  27 <div class="highlight" ><pre><span class="c">/**</span>
  28 <span class="c"> *</span>
  29 <span class="c"> * The Browser History Manager provides the ability to use the </span>
  30 <span class="c"> * back/forward navigation buttons in a DHTML application. It also allows </span>
  31 <span class="c"> * a DHTML application to be bookmarked in a specific state.</span>
  32 <span class="c"> *</span>
  33 <span class="c"> * @module history</span>
  34 <span class="c"> * @requires yahoo,event</span>
  35 <span class="c"> * @namespace YAHOO.util</span>
  36 <span class="c"> * @title Browser History Manager</span>
  37 <span class="c"> * @experimental</span>
  38 <span class="c"> */</span>
  39
  40 <span class="c">/**</span>
  41 <span class="c"> * The History class provides the ability to use the back/forward navigation</span>
  42 <span class="c"> * buttons in a DHTML application. It also allows a DHTML application to</span>
  43 <span class="c"> * be bookmarked in a specific state.</span>
  44 <span class="c"> *</span>
  45 <span class="c"> * @class History</span>
  46 <span class="c"> * @constructor</span>
  47 <span class="c"> */</span>
  48 <span class="nx">YAHOO</span><span class="o">.</span><span class="nx">util</span><span class="o">.</span><span class="nx">History</span> <span class="o">=</span> <span class="o">(</span> <span class="k">function</span><span class="o">()</span> <span class="o">{</span>
  49
  50     <span class="c">/**</span>
  51 <span class="c">     * String identifying which browser we are in.</span>
  52 <span class="c">     * Different code is run depending on which browser you are using.</span>
  53 <span class="c">     *</span>
  54 <span class="c">     * @property _browser</span>
  55 <span class="c">     * @type string</span>
  56 <span class="c">     * @default &quot;unknown&quot;</span>
  57 <span class="c">     * @private</span>
  58 <span class="c">     */</span>
  59     <span class="k">var</span> <span class="nx">_browser</span> <span class="o">=</span> <span class="s2">&quot;unknown&quot;</span><span class="o">;</span>
  60
  61     <span class="c">/**</span>
  62 <span class="c">     * Our hidden IFrame used to store the browsing history.</span>
  63 <span class="c">     *</span>
  64 <span class="c">     * @property _iframe</span>
  65 <span class="c">     * @type HTMLIFrameElement</span>
  66 <span class="c">     * @default null</span>
  67 <span class="c">     * @private</span>
  68 <span class="c">     */</span>
  69     <span class="k">var</span> <span class="nx">_iframe</span> <span class="o">=</span> <span class="kc">null</span><span class="o">;</span>
  70
  71     <span class="c">/**</span>
  72 <span class="c">     * INPUT field (with type=&quot;hidden&quot; or type=&quot;text&quot;) or TEXTAREA.</span>
  73 <span class="c">     * This field keeps the value of the initial state, current state</span>
  74 <span class="c">     * the list of all states across pages within a single browser session.</span>
  75 <span class="c">     *</span>
  76 <span class="c">     * @property _storageField</span>
  77 <span class="c">     * @type HTMLInputElement|HTMLTextAreaElement</span>
  78 <span class="c">     * @default null</span>
  79 <span class="c">     * @private</span>
  80 <span class="c">     */</span>
  81     <span class="k">var</span> <span class="nx">_storageField</span> <span class="o">=</span> <span class="kc">null</span><span class="o">;</span>
  82
  83     <span class="c">/**</span>
  84 <span class="c">     * Flag used to tell whether YAHOO.util.History.initialize has been called.</span>
  85 <span class="c">     *</span>
  86 <span class="c">     * @property _initialized</span>
  87 <span class="c">     * @type boolean</span>
  88 <span class="c">     * @default false</span>
  89 <span class="c">     * @private</span>
  90 <span class="c">     */</span>
  91     <span class="k">var</span> <span class="nx">_initialized</span> <span class="o">=</span> <span class="kc">false</span><span class="o">;</span>
  92
  93     <span class="c">/**</span>
  94 <span class="c">     * Flag used to tell whether the storage field is ready to be used.</span>
  95 <span class="c">     *</span>
  96 <span class="c">     * @property _storageFieldReady</span>
  97 <span class="c">     * @type boolean</span>
  98 <span class="c">     * @default false</span>
  99 <span class="c">     * @private</span>
 100 <span class="c">     */</span>
 101     <span class="k">var</span> <span class="nx">_storageFieldReady</span> <span class="o">=</span> <span class="kc">false</span><span class="o">;</span>
 102
 103     <span class="c">/**</span>
 104 <span class="c">     * Flag used to tell whether the Browser History Manager is ready.</span>
 105 <span class="c">     *</span>
 106 <span class="c">     * @property _bhmReady</span>
 107 <span class="c">     * @type boolean</span>
 108 <span class="c">     * @default false</span>
 109 <span class="c">     * @private</span>
 110 <span class="c">     */</span>
 111     <span class="k">var</span> <span class="nx">_bhmReady</span> <span class="o">=</span> <span class="kc">false</span><span class="o">;</span>
 112
 113     <span class="c">/**</span>
 114 <span class="c">     * List of registered modules.</span>
 115 <span class="c">     *</span>
 116 <span class="c">     * @property _modules</span>
 117 <span class="c">     * @type array</span>
 118 <span class="c">     * @default []</span>
 119 <span class="c">     * @private</span>
 120 <span class="c">     */</span>
 121     <span class="k">var</span> <span class="nx">_modules</span> <span class="o">=</span> <span class="o">[];</span>
 122
 123     <span class="c">/**</span>
 124 <span class="c">     * List of fully qualified states. This is used only by Safari.</span>
 125 <span class="c">     *</span>
 126 <span class="c">     * @property _fqstates</span>
 127 <span class="c">     * @type array</span>
 128 <span class="c">     * @default []</span>
 129 <span class="c">     * @private</span>
 130 <span class="c">     */</span>
 131     <span class="k">var</span> <span class="nx">_fqstates</span> <span class="o">=</span> <span class="o">[];</span>
 132
 133     <span class="c">/**</span>
 134 <span class="c">     * Trims a string.</span>
 135 <span class="c">     *</span>
 136 <span class="c">     * @method _trim</span>
 137 <span class="c">     * @param {string} str The string to be trimmed.</span>
 138 <span class="c">     * @return {string} The trimmed string</span>
 139 <span class="c">     * @private</span>
 140 <span class="c">     */</span>
 141     <span class="k">function</span> <span class="nx">_trim</span><span class="o">(</span> <span class="nx">str</span> <span class="o">)</span> <span class="o">{</span>
 142         <span class="k">return</span> <span class="nx">str</span><span class="o">.</span><span class="nx">replace</span><span class="o">(</span> <span class="sr">/^\s*(\S*(\s+\S+)*)\s*$/</span><span class="o">,</span> <span class="s2">&quot;$1&quot;</span> <span class="o">);</span>
 143     <span class="o">}</span>
 144
 145     <span class="c">/**</span>
 146 <span class="c">     * location.hash is a bit buggy on Opera. I have seen instances where</span>
 147 <span class="c">     * navigating the history using the back/forward buttons, and hence</span>
 148 <span class="c">     * changing the URL, would not change location.hash. That&#39;s ok, the</span>
 149 <span class="c">     * implementation of an equivalent is trivial.</span>
 150 <span class="c">     *</span>
 151 <span class="c">     * @method _getHash</span>
 152 <span class="c">     * @return {string} The hash portion of the document&#39;s location</span>
 153 <span class="c">     * @private</span>
 154 <span class="c">     */</span>
 155     <span class="k">function</span> <span class="nx">_getHash</span><span class="o">()</span> <span class="o">{</span>
 156         <span class="k">var</span> <span class="nx">href</span> <span class="o">=</span> <span class="nx">top</span><span class="o">.</span><span class="nx">location</span><span class="o">.</span><span class="nx">href</span><span class="o">;</span>
 157         <span class="k">var</span> <span class="nx">idx</span> <span class="o">=</span> <span class="nx">href</span><span class="o">.</span><span class="nx">indexOf</span><span class="o">(</span> <span class="s2">&quot;#&quot;</span> <span class="o">);</span>
 158         <span class="k">return</span> <span class="nx">idx</span> <span class="o">&gt;=</span> <span class="m">0</span> <span class="o">?</span> <span class="nx">href</span><span class="o">.</span><span class="nx">substr</span><span class="o">(</span> <span class="nx">idx</span><span class="o">+</span><span class="m">1</span> <span class="o">)</span> <span class="o">:</span> <span class="kc">null</span><span class="o">;</span>
 159     <span class="o">}</span>
 160
 161     <span class="c">/**</span>
 162 <span class="c">     * Stores all the registered modules&#39; initial state and current state.</span>
 163 <span class="c">     * On Safari, we also store all the fully qualified states visited by</span>
 164 <span class="c">     * the application within a single browser session. The storage takes</span>
 165 <span class="c">     * place in the form field specified during initialization.</span>
 166 <span class="c">     *</span>
 167 <span class="c">     * @method _storeStates</span>
 168 <span class="c">     * @private</span>
 169 <span class="c">     */</span>
 170     <span class="k">function</span> <span class="nx">_storeStates</span><span class="o">()</span> <span class="o">{</span>
 171         <span class="k">var</span> <span class="nx">initialStates</span> <span class="o">=</span> <span class="o">[];</span>
 172         <span class="k">var</span> <span class="nx">currentStates</span> <span class="o">=</span> <span class="o">[];</span>
 173         <span class="k">for</span> <span class="o">(</span> <span class="k">var</span> <span class="nx">moduleName</span> <span class="k">in</span> <span class="nx">_modules</span> <span class="o">)</span> <span class="o">{</span>
 174             <span class="k">var</span> <span class="nx">moduleObj</span> <span class="o">=</span> <span class="nx">_modules</span><span class="o">[</span><span class="nx">moduleName</span><span class="o">];</span>
 175             <span class="nx">initialStates</span><span class="o">.</span><span class="nx">push</span><span class="o">(</span> <span class="nx">moduleName</span> <span class="o">+</span> <span class="s2">&quot;=&quot;</span> <span class="o">+</span> <span class="nx">moduleObj</span><span class="o">.</span><span class="nx">initialState</span> <span class="o">);</span>
 176             <span class="nx">currentStates</span><span class="o">.</span><span class="nx">push</span><span class="o">(</span> <span class="nx">moduleName</span> <span class="o">+</span> <span class="s2">&quot;=&quot;</span> <span class="o">+</span> <span class="nx">moduleObj</span><span class="o">.</span><span class="nx">currentState</span> <span class="o">);</span>
 177         <span class="o">}</span>
 178         <span class="nx">_storageField</span><span class="o">.</span><span class="nx">value</span> <span class="o">=</span> <span class="nx">initialStates</span><span class="o">.</span><span class="nx">join</span><span class="o">(</span> <span class="s2">&quot;&amp;&quot;</span> <span class="o">)</span> <span class="o">+</span> <span class="s2">&quot;|&quot;</span> <span class="o">+</span> <span class="nx">currentStates</span><span class="o">.</span><span class="nx">join</span><span class="o">(</span> <span class="s2">&quot;&amp;&quot;</span> <span class="o">);</span>
 179         <span class="k">if</span> <span class="o">(</span> <span class="nx">_browser</span> <span class="o">==</span> <span class="s2">&quot;safari&quot;</span> <span class="o">)</span> <span class="o">{</span>
 180             <span class="nx">_storageField</span><span class="o">.</span><span class="nx">value</span> <span class="o">+=</span> <span class="s2">&quot;|&quot;</span> <span class="o">+</span> <span class="nx">_fqstates</span><span class="o">.</span><span class="nx">join</span><span class="o">(</span> <span class="s2">&quot;,&quot;</span> <span class="o">);</span>
 181         <span class="o">}</span>
 182     <span class="o">}</span>
 183
 184     <span class="c">/**</span>
 185 <span class="c">     * Periodically checks whether our internal IFrame is ready to be used.</span>
 186 <span class="c">     *</span>
 187 <span class="c">     * @method _checkIframeLoaded</span>
 188 <span class="c">     * @private</span>
 189 <span class="c">     */</span>
 190     <span class="k">function</span> <span class="nx">_checkIframeLoaded</span><span class="o">()</span> <span class="o">{</span>
 191         <span class="k">if</span> <span class="o">(</span> <span class="o">!</span><span class="nx">_iframe</span><span class="o">.</span><span class="nx">contentWindow</span> <span class="o">||</span> <span class="o">!</span><span class="nx">_iframe</span><span class="o">.</span><span class="nx">contentWindow</span><span class="o">.</span><span class="nb">document</span> <span class="o">)</span> <span class="o">{</span>
 192             <span class="c">// Check again in 10 msec...</span>
 193 <span class="c"></span>            <span class="nx">setTimeout</span><span class="o">(</span> <span class="nx">_checkIframeLoaded</span><span class="o">,</span> <span class="m">10</span> <span class="o">);</span>
 194             <span class="k">return</span><span class="o">;</span>
 195         <span class="o">}</span>
 196
 197         <span class="c">// Start the thread that will have the responsibility to</span>
 198 <span class="c"></span>        <span class="c">// periodically check whether a navigate operation has been</span>
 199 <span class="c"></span>        <span class="c">// requested on the main window. This will happen when</span>
 200 <span class="c"></span>        <span class="c">// YAHOO.util.History.navigate has been called or after</span>
 201 <span class="c"></span>        <span class="c">// the user has hit the back/forward button.</span>
 202 <span class="c"></span>
 203         <span class="k">var</span> <span class="nx">doc</span> <span class="o">=</span> <span class="nx">_iframe</span><span class="o">.</span><span class="nx">contentWindow</span><span class="o">.</span><span class="nb">document</span><span class="o">;</span>
 204         <span class="k">var</span> <span class="nx">elem</span> <span class="o">=</span> <span class="nx">doc</span><span class="o">.</span><span class="nx">getElementById</span><span class="o">(</span> <span class="s2">&quot;state&quot;</span> <span class="o">);</span>
 205         <span class="c">// We must use innerText, and not innerHTML because our string contains</span>
 206 <span class="c"></span>        <span class="c">// the &quot;&amp;&quot; character (which would end up being escaped as &quot;&amp;amp;&quot;) and</span>
 207 <span class="c"></span>        <span class="c">// the string comparison would fail...</span>
 208 <span class="c"></span>        <span class="k">var</span> <span class="nx">fqstate</span> <span class="o">=</span> <span class="nx">elem</span> <span class="o">?</span> <span class="nx">elem</span><span class="o">.</span><span class="nx">innerText</span> <span class="o">:</span> <span class="kc">null</span><span class="o">;</span>
 209
 210         <span class="nx">setInterval</span><span class="o">(</span> <span class="k">function</span><span class="o">()</span> <span class="o">{</span>
 211             <span class="nx">doc</span> <span class="o">=</span> <span class="nx">_iframe</span><span class="o">.</span><span class="nx">contentWindow</span><span class="o">.</span><span class="nb">document</span><span class="o">;</span>
 212             <span class="nx">elem</span> <span class="o">=</span> <span class="nx">doc</span><span class="o">.</span><span class="nx">getElementById</span><span class="o">(</span> <span class="s2">&quot;state&quot;</span> <span class="o">);</span>
 213             <span class="c">// See my comment above about using innerText instead of innerHTML...</span>
 214 <span class="c"></span>            <span class="k">var</span> <span class="nx">newfqstate</span> <span class="o">=</span> <span class="nx">elem</span> <span class="o">?</span> <span class="nx">elem</span><span class="o">.</span><span class="nx">innerText</span> <span class="o">:</span> <span class="kc">null</span><span class="o">;</span>
 215             <span class="k">if</span> <span class="o">(</span> <span class="nx">newfqstate</span> <span class="o">!=</span> <span class="nx">fqstate</span> <span class="o">)</span> <span class="o">{</span>
 216                 <span class="nx">fqstate</span> <span class="o">=</span> <span class="nx">newfqstate</span><span class="o">;</span>
 217                 <span class="nx">_handleFQStateChange</span><span class="o">(</span> <span class="nx">fqstate</span> <span class="o">);</span>
 218
 219                 <span class="k">var</span> <span class="nx">hash</span><span class="o">;</span>
 220                 <span class="k">if</span> <span class="o">(</span> <span class="o">!</span><span class="nx">fqstate</span> <span class="o">)</span> <span class="o">{</span>
 221                     <span class="k">var</span> <span class="nx">states</span> <span class="o">=</span> <span class="o">[];</span>
 222                     <span class="k">for</span> <span class="o">(</span> <span class="k">var</span> <span class="nx">moduleName</span> <span class="k">in</span> <span class="nx">_modules</span> <span class="o">)</span> <span class="o">{</span>
 223                         <span class="k">var</span> <span class="nx">moduleObj</span> <span class="o">=</span> <span class="nx">_modules</span><span class="o">[</span><span class="nx">moduleName</span><span class="o">];</span>
 224                         <span class="nx">states</span><span class="o">.</span><span class="nx">push</span><span class="o">(</span> <span class="nx">moduleName</span> <span class="o">+</span> <span class="s2">&quot;=&quot;</span> <span class="o">+</span> <span class="nx">moduleObj</span><span class="o">.</span><span class="nx">initialState</span> <span class="o">);</span>
 225                     <span class="o">}</span>
 226                     <span class="nx">hash</span> <span class="o">=</span> <span class="nx">states</span><span class="o">.</span><span class="nx">join</span><span class="o">(</span> <span class="s2">&quot;&amp;&quot;</span> <span class="o">);</span>
 227                 <span class="o">}</span> <span class="k">else</span> <span class="o">{</span>
 228                     <span class="nx">hash</span> <span class="o">=</span> <span class="nx">fqstate</span><span class="o">;</span>
 229                 <span class="o">}</span>
 230
 231                 <span class="c">// Allow the state to be bookmarked without messing up the browser history...</span>
 232 <span class="c"></span>                <span class="nx">top</span><span class="o">.</span><span class="nx">location</span><span class="o">.</span><span class="nx">replace</span><span class="o">(</span> <span class="s2">&quot;#&quot;</span> <span class="o">+</span> <span class="nx">hash</span> <span class="o">);</span>
 233
 234                 <span class="nx">_storeStates</span><span class="o">();</span>
 235             <span class="o">}</span>
 236         <span class="o">},</span> <span class="m">50</span> <span class="o">);</span>
 237
 238         <span class="nx">_bhmReady</span> <span class="o">=</span> <span class="kc">true</span><span class="o">;</span>
 239
 240         <span class="nx">YAHOO</span><span class="o">.</span><span class="nx">util</span><span class="o">.</span><span class="nx">History</span><span class="o">.</span><span class="nx">onLoadEvent</span><span class="o">.</span><span class="nx">fire</span><span class="o">();</span>
 241     <span class="o">}</span>
 242
 243     <span class="c">/**</span>
 244 <span class="c">     * Sets the new currentState attribute of all modules depending on the new</span>
 245 <span class="c">     * fully qualified state. Also notifies the modules which current state has</span>
 246 <span class="c">     * changed.</span>
 247 <span class="c">     *</span>
 248 <span class="c">     * @method _handleFQStateChange</span>
 249 <span class="c">     * @param {string} fqstate Fully qualified state</span>
 250 <span class="c">     * @private</span>
 251 <span class="c">     */</span>
 252     <span class="k">function</span> <span class="nx">_handleFQStateChange</span><span class="o">(</span> <span class="nx">fqstate</span> <span class="o">)</span> <span class="o">{</span>
 253         <span class="k">var</span> <span class="nx">moduleName</span><span class="o">,</span> <span class="nx">moduleObj</span><span class="o">,</span> <span class="nx">currentState</span><span class="o">;</span>
 254
 255         <span class="k">if</span> <span class="o">(</span> <span class="o">!</span><span class="nx">fqstate</span> <span class="o">)</span> <span class="o">{</span>
 256             <span class="c">// Notifies all modules</span>
 257 <span class="c"></span>            <span class="k">for</span> <span class="o">(</span> <span class="nx">moduleName</span> <span class="k">in</span> <span class="nx">_modules</span> <span class="o">)</span> <span class="o">{</span>
 258                 <span class="nx">moduleObj</span> <span class="o">=</span> <span class="nx">_modules</span><span class="o">[</span><span class="nx">moduleName</span><span class="o">];</span>
 259                 <span class="nx">moduleObj</span><span class="o">.</span><span class="nx">currentState</span> <span class="o">=</span> <span class="nx">moduleObj</span><span class="o">.</span><span class="nx">initialState</span><span class="o">;</span>
 260                 <span class="nx">moduleObj</span><span class="o">.</span><span class="nx">onStateChange</span><span class="o">(</span> <span class="nx">moduleObj</span><span class="o">.</span><span class="nx">currentState</span> <span class="o">);</span>
 261             <span class="o">}</span>
 262             <span class="k">return</span><span class="o">;</span>
 263         <span class="o">}</span>
 264
 265         <span class="k">var</span> <span class="nx">modules</span> <span class="o">=</span> <span class="o">[];</span>
 266         <span class="k">var</span> <span class="nx">states</span> <span class="o">=</span> <span class="nx">fqstate</span><span class="o">.</span><span class="nx">split</span><span class="o">(</span> <span class="s2">&quot;&amp;&quot;</span> <span class="o">);</span>
 267         <span class="k">for</span> <span class="o">(</span> <span class="k">var</span> <span class="nx">idx</span><span class="o">=</span><span class="m">0</span><span class="o">,</span> <span class="nx">len</span><span class="o">=</span><span class="nx">states</span><span class="o">.</span><span class="nx">length</span> <span class="o">;</span> <span class="nx">idx</span><span class="o">&lt;</span><span class="nx">len</span> <span class="o">;</span> <span class="nx">idx</span><span class="o">++</span> <span class="o">)</span> <span class="o">{</span>
 268             <span class="k">var</span> <span class="nx">tokens</span> <span class="o">=</span> <span class="nx">states</span><span class="o">[</span><span class="nx">idx</span><span class="o">].</span><span class="nx">split</span><span class="o">(</span> <span class="s2">&quot;=&quot;</span> <span class="o">);</span>
 269             <span class="k">if</span> <span class="o">(</span> <span class="nx">tokens</span><span class="o">.</span><span class="nx">length</span> <span class="o">==</span> <span class="m">2</span> <span class="o">)</span> <span class="o">{</span>
 270                 <span class="nx">moduleName</span> <span class="o">=</span> <span class="nx">tokens</span><span class="o">[</span><span class="m">0</span><span class="o">];</span>
 271                 <span class="nx">currentState</span> <span class="o">=</span> <span class="nx">tokens</span><span class="o">[</span><span class="m">1</span><span class="o">];</span>
 272                 <span class="nx">modules</span><span class="o">[</span><span class="nx">moduleName</span><span class="o">]</span> <span class="o">=</span> <span class="nx">currentState</span><span class="o">;</span>
 273             <span class="o">}</span>
 274         <span class="o">}</span>
 275
 276         <span class="k">for</span> <span class="o">(</span> <span class="nx">moduleName</span> <span class="k">in</span> <span class="nx">_modules</span> <span class="o">)</span> <span class="o">{</span>
 277             <span class="nx">moduleObj</span> <span class="o">=</span> <span class="nx">_modules</span><span class="o">[</span><span class="nx">moduleName</span><span class="o">];</span>
 278             <span class="nx">currentState</span> <span class="o">=</span> <span class="nx">modules</span><span class="o">[</span><span class="nx">moduleName</span><span class="o">];</span>
 279             <span class="k">if</span> <span class="o">(</span> <span class="o">!</span><span class="nx">currentState</span> <span class="o">||</span> <span class="nx">moduleObj</span><span class="o">.</span><span class="nx">currentState</span> <span class="o">!=</span> <span class="nx">currentState</span> <span class="o">)</span> <span class="o">{</span>
 280                 <span class="nx">moduleObj</span><span class="o">.</span><span class="nx">currentState</span> <span class="o">=</span> <span class="nx">currentState</span> <span class="o">||</span> <span class="nx">moduleObj</span><span class="o">.</span><span class="nx">initialState</span><span class="o">;</span>
 281                 <span class="nx">moduleObj</span><span class="o">.</span><span class="nx">onStateChange</span><span class="o">(</span> <span class="nx">moduleObj</span><span class="o">.</span><span class="nx">currentState</span> <span class="o">);</span>
 282             <span class="o">}</span>
 283         <span class="o">}</span>
 284     <span class="o">}</span>
 285
 286     <span class="c">/**</span>
 287 <span class="c">     * Finish up the initialization of the Browser History Manager.</span>
 288 <span class="c">     *</span>
 289 <span class="c">     * @method _initialize</span>
 290 <span class="c">     * @private</span>
 291 <span class="c">     */</span>
 292     <span class="k">function</span> <span class="nx">_initialize</span><span class="o">()</span> <span class="o">{</span>
 293
 294         <span class="nx">_storageField</span> <span class="o">=</span> <span class="nb">document</span><span class="o">.</span><span class="nx">getElementById</span><span class="o">(</span> <span class="s2">&quot;yui_hist_field&quot;</span> <span class="o">);</span>
 295
 296         <span class="c">// Decode the content of our storage field...</span>
 297 <span class="c"></span>        <span class="k">var</span> <span class="nx">parts</span> <span class="o">=</span> <span class="nx">_storageField</span><span class="o">.</span><span class="nx">value</span><span class="o">.</span><span class="nx">split</span><span class="o">(</span> <span class="s2">&quot;|&quot;</span> <span class="o">);</span>
 298
 299         <span class="k">if</span> <span class="o">(</span> <span class="nx">parts</span><span class="o">.</span><span class="nx">length</span> <span class="o">&gt;</span> <span class="m">1</span> <span class="o">)</span> <span class="o">{</span>
 300
 301             <span class="k">var</span> <span class="nx">idx</span><span class="o">,</span> <span class="nx">len</span><span class="o">,</span> <span class="nx">tokens</span><span class="o">,</span> <span class="nx">moduleName</span><span class="o">,</span> <span class="nx">moduleObj</span><span class="o">;</span>
 302
 303             <span class="k">var</span> <span class="nx">initialStates</span> <span class="o">=</span> <span class="nx">parts</span><span class="o">[</span><span class="m">0</span><span class="o">].</span><span class="nx">split</span><span class="o">(</span> <span class="s2">&quot;&amp;&quot;</span> <span class="o">);</span>
 304             <span class="k">for</span> <span class="o">(</span> <span class="nx">idx</span><span class="o">=</span><span class="m">0</span><span class="o">,</span> <span class="nx">len</span><span class="o">=</span><span class="nx">initialStates</span><span class="o">.</span><span class="nx">length</span> <span class="o">;</span> <span class="nx">idx</span><span class="o">&lt;</span><span class="nx">len</span> <span class="o">;</span> <span class="nx">idx</span><span class="o">++</span> <span class="o">)</span> <span class="o">{</span>
 305                 <span class="nx">tokens</span> <span class="o">=</span> <span class="nx">initialStates</span><span class="o">[</span><span class="nx">idx</span><span class="o">].</span><span class="nx">split</span><span class="o">(</span> <span class="s2">&quot;=&quot;</span> <span class="o">);</span>
 306                 <span class="k">if</span> <span class="o">(</span> <span class="nx">tokens</span><span class="o">.</span><span class="nx">length</span> <span class="o">==</span> <span class="m">2</span> <span class="o">)</span> <span class="o">{</span>
 307                     <span class="nx">moduleName</span> <span class="o">=</span> <span class="nx">tokens</span><span class="o">[</span><span class="m">0</span><span class="o">];</span>
 308                     <span class="k">var</span> <span class="nx">initialState</span> <span class="o">=</span> <span class="nx">tokens</span><span class="o">[</span><span class="m">1</span><span class="o">];</span>
 309                     <span class="nx">moduleObj</span> <span class="o">=</span> <span class="nx">_modules</span><span class="o">[</span><span class="nx">moduleName</span><span class="o">];</span>
 310                     <span class="k">if</span> <span class="o">(</span> <span class="nx">moduleObj</span> <span class="o">)</span> <span class="o">{</span>
 311                         <span class="nx">moduleObj</span><span class="o">.</span><span class="nx">initialState</span> <span class="o">=</span> <span class="nx">initialState</span><span class="o">;</span>
 312                     <span class="o">}</span>
 313                 <span class="o">}</span>
 314             <span class="o">}</span>
 315
 316             <span class="k">var</span> <span class="nx">currentStates</span> <span class="o">=</span> <span class="nx">parts</span><span class="o">[</span><span class="m">1</span><span class="o">].</span><span class="nx">split</span><span class="o">(</span> <span class="s2">&quot;&amp;&quot;</span> <span class="o">);</span>
 317             <span class="k">for</span> <span class="o">(</span> <span class="nx">idx</span><span class="o">=</span><span class="m">0</span><span class="o">,</span> <span class="nx">len</span><span class="o">=</span><span class="nx">currentStates</span><span class="o">.</span><span class="nx">length</span> <span class="o">;</span> <span class="nx">idx</span><span class="o">&lt;</span><span class="nx">len</span> <span class="o">;</span> <span class="nx">idx</span><span class="o">++</span> <span class="o">)</span> <span class="o">{</span>
 318                 <span class="nx">tokens</span> <span class="o">=</span> <span class="nx">currentStates</span><span class="o">[</span><span class="nx">idx</span><span class="o">].</span><span class="nx">split</span><span class="o">(</span> <span class="s2">&quot;=&quot;</span> <span class="o">);</span>
 319                 <span class="k">if</span> <span class="o">(</span> <span class="nx">tokens</span><span class="o">.</span><span class="nx">length</span> <span class="o">&gt;=</span> <span class="m">2</span> <span class="o">)</span> <span class="o">{</span>
 320                     <span class="nx">moduleName</span> <span class="o">=</span> <span class="nx">tokens</span><span class="o">[</span><span class="m">0</span><span class="o">];</span>
 321                     <span class="k">var</span> <span class="nx">currentState</span> <span class="o">=</span> <span class="nx">tokens</span><span class="o">[</span><span class="m">1</span><span class="o">];</span>
 322                     <span class="nx">moduleObj</span> <span class="o">=</span> <span class="nx">_modules</span><span class="o">[</span><span class="nx">moduleName</span><span class="o">];</span>
 323                     <span class="k">if</span> <span class="o">(</span> <span class="nx">moduleObj</span> <span class="o">)</span> <span class="o">{</span>
 324                         <span class="nx">moduleObj</span><span class="o">.</span><span class="nx">currentState</span> <span class="o">=</span> <span class="nx">currentState</span><span class="o">;</span>
 325                     <span class="o">}</span>
 326                 <span class="o">}</span>
 327             <span class="o">}</span>
 328         <span class="o">}</span>
 329
 330         <span class="k">if</span> <span class="o">(</span> <span class="nx">parts</span><span class="o">.</span><span class="nx">length</span> <span class="o">&gt;</span> <span class="m">2</span> <span class="o">)</span> <span class="o">{</span>
 331             <span class="nx">_fqstates</span> <span class="o">=</span> <span class="nx">parts</span><span class="o">[</span><span class="m">2</span><span class="o">].</span><span class="nx">split</span><span class="o">(</span> <span class="s2">&quot;,&quot;</span> <span class="o">);</span>
 332         <span class="o">}</span>
 333
 334         <span class="nx">_storageFieldReady</span> <span class="o">=</span> <span class="kc">true</span><span class="o">;</span>
 335
 336         <span class="k">if</span> <span class="o">(</span> <span class="nx">_browser</span> <span class="o">==</span> <span class="s2">&quot;msie&quot;</span> <span class="o">)</span> <span class="o">{</span>
 337
 338             <span class="nx">_iframe</span> <span class="o">=</span> <span class="nb">document</span><span class="o">.</span><span class="nx">getElementById</span><span class="o">(</span> <span class="s2">&quot;yui_hist_iframe&quot;</span> <span class="o">);</span>
 339             <span class="nx">_checkIframeLoaded</span><span class="o">();</span>
 340
 341         <span class="o">}</span> <span class="k">else</span> <span class="o">{</span>
 342
 343             <span class="c">// Start the thread that will have the responsibility to</span>
 344 <span class="c"></span>            <span class="c">// periodically check whether a navigate operation has been</span>
 345 <span class="c"></span>            <span class="c">// requested on the main window. This will happen when</span>
 346 <span class="c"></span>            <span class="c">// YAHOO.util.History.navigate has been called or after</span>
 347 <span class="c"></span>            <span class="c">// the user has hit the back/forward button.</span>
 348 <span class="c"></span>
 349             <span class="c">// On Safari 1.x and 2.0, the only way to catch a back/forward</span>
 350 <span class="c"></span>            <span class="c">// operation is to watch history.length... We basically exploit</span>
 351 <span class="c"></span>            <span class="c">// what I consider to be a bug (history.length is not supposed</span>
 352 <span class="c"></span>            <span class="c">// to change when going back/forward in the history...) This is</span>
 353 <span class="c"></span>            <span class="c">// why, in the following thread, we first compare the hash,</span>
 354 <span class="c"></span>            <span class="c">// because the hash thing will be fixed in the next major</span>
 355 <span class="c"></span>            <span class="c">// version of Safari. So even if they fix the history.length</span>
 356 <span class="c"></span>            <span class="c">// bug, all this will still work!</span>
 357 <span class="c"></span>            <span class="k">var</span> <span class="nx">counter</span> <span class="o">=</span> <span class="nx">history</span><span class="o">.</span><span class="nx">length</span><span class="o">;</span>
 358
 359             <span class="c">// On Gecko and Opera, we just need to watch the hash...</span>
 360 <span class="c"></span>            <span class="k">var</span> <span class="nx">hash</span> <span class="o">=</span> <span class="nx">_getHash</span><span class="o">();</span>
 361
 362             <span class="nx">setInterval</span><span class="o">(</span> <span class="k">function</span><span class="o">()</span> <span class="o">{</span>
 363                 <span class="k">var</span> <span class="nx">state</span><span class="o">;</span>
 364                 <span class="k">var</span> <span class="nx">newHash</span> <span class="o">=</span> <span class="nx">_getHash</span><span class="o">();</span>
 365                 <span class="k">var</span> <span class="nx">newCounter</span> <span class="o">=</span> <span class="nx">history</span><span class="o">.</span><span class="nx">length</span><span class="o">;</span>
 366                 <span class="k">if</span> <span class="o">(</span> <span class="nx">newHash</span> <span class="o">!=</span> <span class="nx">hash</span> <span class="o">)</span> <span class="o">{</span>
 367                     <span class="nx">hash</span> <span class="o">=</span> <span class="nx">newHash</span><span class="o">;</span>
 368                     <span class="nx">counter</span> <span class="o">=</span> <span class="nx">newCounter</span><span class="o">;</span>
 369                     <span class="nx">_handleFQStateChange</span><span class="o">(</span> <span class="nx">hash</span> <span class="o">);</span>
 370                     <span class="nx">_storeStates</span><span class="o">();</span>
 371                 <span class="o">}</span> <span class="k">else</span> <span class="k">if</span> <span class="o">(</span> <span class="nx">newCounter</span> <span class="o">!=</span> <span class="nx">counter</span> <span class="o">)</span> <span class="o">{</span>
 372                     <span class="c">// If we ever get here, we should be on Safari...</span>
 373 <span class="c"></span>                    <span class="nx">hash</span> <span class="o">=</span> <span class="nx">newHash</span><span class="o">;</span>
 374                     <span class="nx">counter</span> <span class="o">=</span> <span class="nx">newCounter</span><span class="o">;</span>
 375                     <span class="nx">state</span> <span class="o">=</span> <span class="nx">_fqstates</span><span class="o">[</span><span class="nx">counter</span><span class="o">-</span><span class="m">1</span><span class="o">];</span>
 376                     <span class="nx">_handleFQStateChange</span><span class="o">(</span> <span class="nx">state</span> <span class="o">);</span>
 377                     <span class="nx">_storeStates</span><span class="o">();</span>
 378                 <span class="o">}</span>
 379             <span class="o">},</span> <span class="m">50</span> <span class="o">);</span>
 380
 381             <span class="nx">_bhmReady</span> <span class="o">=</span> <span class="kc">true</span><span class="o">;</span>
 382
 383             <span class="nx">YAHOO</span><span class="o">.</span><span class="nx">util</span><span class="o">.</span><span class="nx">History</span><span class="o">.</span><span class="nx">onLoadEvent</span><span class="o">.</span><span class="nx">fire</span><span class="o">();</span>
 384         <span class="o">}</span>
 385     <span class="o">}</span>
 386
 387     <span class="c">// Simple browser detection code</span>
 388 <span class="c"></span>    <span class="c">// After talking with Matt Sweeney, I moved back to using the</span>
 389 <span class="c"></span>    <span class="c">// user agent string instead of doing browser detection.</span>
 390 <span class="c"></span>    <span class="k">var</span> <span class="nx">ua</span> <span class="o">=</span> <span class="nx">navigator</span><span class="o">.</span><span class="nx">userAgent</span><span class="o">.</span><span class="nx">toLowerCase</span><span class="o">();</span>
 391     <span class="k">if</span> <span class="o">(</span> <span class="nx">ua</span><span class="o">.</span><span class="nx">indexOf</span><span class="o">(</span> <span class="s2">&quot;opera&quot;</span> <span class="o">)</span> <span class="o">!=</span> <span class="o">-</span><span class="m">1</span> <span class="o">)</span> <span class="o">{</span>
 392         <span class="c">// Opera (check first in case of spoof)</span>
 393 <span class="c"></span>        <span class="nx">_browser</span> <span class="o">=</span> <span class="s2">&quot;opera&quot;</span><span class="o">;</span>
 394     <span class="o">}</span> <span class="k">else</span> <span class="k">if</span> <span class="o">(</span> <span class="nx">ua</span><span class="o">.</span><span class="nx">indexOf</span><span class="o">(</span> <span class="s2">&quot;msie&quot;</span> <span class="o">)</span> <span class="o">!=</span> <span class="o">-</span><span class="m">1</span> <span class="o">)</span> <span class="o">{</span>
 395         <span class="c">// Microsoft Internet Explorer and derivatives...</span>
 396 <span class="c"></span>        <span class="nx">_browser</span> <span class="o">=</span> <span class="s2">&quot;msie&quot;</span><span class="o">;</span>
 397     <span class="o">}</span> <span class="k">else</span> <span class="k">if</span> <span class="o">(</span> <span class="nx">ua</span><span class="o">.</span><span class="nx">indexOf</span><span class="o">(</span> <span class="s2">&quot;safari&quot;</span> <span class="o">)</span> <span class="o">!=</span> <span class="o">-</span><span class="m">1</span> <span class="o">)</span> <span class="o">{</span>
 398         <span class="c">// Safari (check before Gecko because it includes &quot;like Gecko&quot;)</span>
 399 <span class="c"></span>        <span class="nx">_browser</span> <span class="o">=</span> <span class="s2">&quot;safari&quot;</span><span class="o">;</span>
 400     <span class="o">}</span> <span class="k">else</span> <span class="k">if</span> <span class="o">(</span> <span class="nx">ua</span><span class="o">.</span><span class="nx">indexOf</span><span class="o">(</span> <span class="s2">&quot;gecko&quot;</span> <span class="o">)</span> <span class="o">!=</span> <span class="o">-</span><span class="m">1</span> <span class="o">)</span> <span class="o">{</span>
 401         <span class="c">// Gecko</span>
 402 <span class="c"></span>        <span class="nx">_browser</span> <span class="o">=</span> <span class="s2">&quot;gecko&quot;</span><span class="o">;</span>
 403     <span class="o">}</span>
 404
 405     <span class="k">return</span> <span class="o">{</span>
 406
 407         <span class="c">/**</span>
 408 <span class="c">         * Fired when the Browser History Manager is ready.</span>
 409 <span class="c">         *</span>
 410 <span class="c">         * @event onLoadEvent</span>
 411 <span class="c">         */</span>
 412         <span class="nx">onLoadEvent</span> <span class="o">:</span> <span class="k">new</span> <span class="nx">YAHOO</span><span class="o">.</span><span class="nx">util</span><span class="o">.</span><span class="nx">CustomEvent</span><span class="o">(</span> <span class="s2">&quot;onLoad&quot;</span> <span class="o">),</span>
 413
 414         <span class="c">/**</span>
 415 <span class="c">         * Registers a new module.</span>
 416 <span class="c">         *</span>
 417 <span class="c">         * @method register</span>
 418 <span class="c">         * @param {string} module Non-empty string uniquely identifying the</span>
 419 <span class="c">         *     module you wish to register.</span>
 420 <span class="c">         * @param {string} initialState The initial state of the specified</span>
 421 <span class="c">         *     module corresponding to its earliest history entry.</span>
 422 <span class="c">         * @param {function} onStateChange Callback called when the</span>
 423 <span class="c">         *     state of the specified module has changed.</span>
 424 <span class="c">         */</span>
 425         <span class="nx">register</span> <span class="o">:</span> <span class="k">function</span><span class="o">(</span> <span class="nx">module</span><span class="o">,</span> <span class="nx">initialState</span><span class="o">,</span> <span class="nx">onStateChange</span> <span class="o">)</span> <span class="o">{</span>
 426             <span class="k">if</span> <span class="o">(</span> <span class="k">typeof</span> <span class="nx">module</span> <span class="o">!=</span> <span class="s2">&quot;string&quot;</span> <span class="o">||</span> <span class="nx">_trim</span><span class="o">(</span> <span class="nx">module</span> <span class="o">)</span> <span class="o">===</span> <span class="s2">&quot;&quot;</span> <span class="o">||</span>
 427                  <span class="k">typeof</span> <span class="nx">initialState</span> <span class="o">!=</span> <span class="s2">&quot;string&quot;</span> <span class="o">||</span>
 428                  <span class="k">typeof</span> <span class="nx">onStateChange</span> <span class="o">!=</span> <span class="s2">&quot;function&quot;</span> <span class="o">)</span> <span class="o">{</span>
 429                 <span class="k">throw</span> <span class="k">new</span> <span class="nb">Error</span><span class="o">(</span> <span class="s2">&quot;Missing or invalid argument passed to YAHOO.util.History.register&quot;</span> <span class="o">);</span>
 430             <span class="o">}</span>
 431
 432             <span class="k">if</span> <span class="o">(</span> <span class="nx">_modules</span><span class="o">[</span><span class="nx">module</span><span class="o">]</span> <span class="o">)</span> <span class="o">{</span>
 433                 <span class="k">throw</span> <span class="k">new</span> <span class="nb">Error</span><span class="o">(</span> <span class="s2">&quot;A module cannot be registered twice&quot;</span> <span class="o">);</span>
 434             <span class="o">}</span>
 435
 436             <span class="c">// Note: A module CANNOT be registered after calling</span>
 437 <span class="c"></span>            <span class="c">// YAHOO.util.History.initialize. Indeed, we set the initial state</span>
 438 <span class="c"></span>            <span class="c">// of each registered module in YAHOO.util.History.initialize.</span>
 439 <span class="c"></span>            <span class="c">// If you could register a module after initializing the Browser</span>
 440 <span class="c"></span>            <span class="c">// History Manager, you would not read the correct state using</span>
 441 <span class="c"></span>            <span class="c">// YAHOO.util.History.getCurrentState when coming back to the</span>
 442 <span class="c"></span>            <span class="c">// page using the back button.</span>
 443 <span class="c"></span>            <span class="k">if</span> <span class="o">(</span> <span class="nx">_initialized</span> <span class="o">)</span> <span class="o">{</span>
 444                 <span class="k">throw</span> <span class="k">new</span> <span class="nb">Error</span><span class="o">(</span> <span class="s2">&quot;All modules must be registered before calling YAHOO.util.History.initialize&quot;</span> <span class="o">);</span>
 445             <span class="o">}</span>
 446
 447             <span class="c">// Make sure the strings passed in do not contain our separators &quot;,&quot; and &quot;|&quot;</span>
 448 <span class="c"></span>            <span class="nx">module</span> <span class="o">=</span> <span class="nx">escape</span><span class="o">(</span> <span class="nx">module</span> <span class="o">);</span>
 449             <span class="nx">initialState</span> <span class="o">=</span> <span class="nx">escape</span><span class="o">(</span> <span class="nx">initialState</span> <span class="o">);</span>
 450
 451             <span class="nx">_modules</span><span class="o">[</span><span class="nx">module</span><span class="o">]</span> <span class="o">=</span> <span class="o">{</span>
 452                 <span class="nx">name</span> <span class="o">:</span> <span class="nx">module</span><span class="o">,</span>
 453                 <span class="nx">initialState</span> <span class="o">:</span> <span class="nx">initialState</span><span class="o">,</span>
 454                 <span class="nx">currentState</span> <span class="o">:</span> <span class="nx">initialState</span><span class="o">,</span>
 455                 <span class="nx">onStateChange</span> <span class="o">:</span> <span class="nx">onStateChange</span>
 456             <span class="o">};</span>
 457         <span class="o">},</span>
 458
 459         <span class="c">/**</span>
 460 <span class="c">         * Initializes the Browser History Manager. Call this method</span>
 461 <span class="c">         * from a script block located right after the opening body tag.</span>
 462 <span class="c">         *</span>
 463 <span class="c">         * @method initialize</span>
 464 <span class="c">         * @param {string} iframeTarget Optional - Path to an existing</span>
 465 <span class="c">         *     HTML document accessible from the same domain. If not</span>
 466 <span class="c">         *     specified, defaults to &quot;blank.html&quot;</span>
 467 <span class="c">         * @public</span>
 468 <span class="c">         */</span>
 469         <span class="nx">initialize</span> <span class="o">:</span> <span class="k">function</span><span class="o">(</span> <span class="nx">iframeTarget</span> <span class="o">)</span> <span class="o">{</span>
 470             <span class="c">// Return if the browser history manager has already been initialized</span>
 471 <span class="c"></span>            <span class="k">if</span> <span class="o">(</span> <span class="nx">_initialized</span> <span class="o">)</span> <span class="o">{</span>
 472                 <span class="k">return</span><span class="o">;</span>
 473             <span class="o">}</span>
 474
 475             <span class="k">if</span> <span class="o">(</span> <span class="nx">_browser</span> <span class="o">==</span> <span class="s2">&quot;unknown&quot;</span> <span class="o">)</span> <span class="o">{</span>
 476                 <span class="k">throw</span> <span class="k">new</span> <span class="nb">Error</span><span class="o">(</span> <span class="s2">&quot;Your web browser is not supported by the Browser History Manager&quot;</span> <span class="o">);</span>
 477             <span class="o">}</span>
 478
 479             <span class="k">if</span> <span class="o">(</span> <span class="o">!</span><span class="nx">iframeTarget</span> <span class="o">)</span> <span class="o">{</span>
 480                 <span class="nx">iframeTarget</span> <span class="o">=</span> <span class="s2">&quot;blank.html&quot;</span><span class="o">;</span>
 481             <span class="o">}</span>
 482
 483             <span class="k">if</span> <span class="o">(</span> <span class="k">typeof</span> <span class="nx">iframeTarget</span> <span class="o">!=</span> <span class="s2">&quot;string&quot;</span> <span class="o">||</span> <span class="nx">_trim</span><span class="o">(</span> <span class="nx">iframeTarget</span> <span class="o">)</span> <span class="o">===</span> <span class="s2">&quot;&quot;</span> <span class="o">)</span> <span class="o">{</span>
 484                 <span class="k">throw</span> <span class="k">new</span> <span class="nb">Error</span><span class="o">(</span> <span class="s2">&quot;Invalid argument passed to YAHOO.util.History.initialize&quot;</span> <span class="o">);</span>
 485             <span class="o">}</span>
 486
 487             <span class="nb">document</span><span class="o">.</span><span class="nx">write</span><span class="o">(</span> <span class="s1">&#39;&lt;input type=&quot;hidden&quot; id=&quot;yui_hist_field&quot;&gt;&#39;</span> <span class="o">);</span>
 488             <span class="k">if</span> <span class="o">(</span> <span class="nx">_browser</span> <span class="o">==</span> <span class="s2">&quot;msie&quot;</span> <span class="o">)</span> <span class="o">{</span>
 489                 <span class="c">// Pointing the IFrame to a file on the server is absolutely</span>
 490 <span class="c"></span>                <span class="c">// essential. I tried to point it to nothing (by setting</span>
 491 <span class="c"></span>                <span class="c">// src=&quot;&quot;) and create the initial entry in the browser</span>
 492 <span class="c"></span>                <span class="c">// history (by using document.write) but it did not work</span>
 493 <span class="c"></span>                <span class="c">// when coming back to the page... Also, the file must exist</span>
 494 <span class="c"></span>                <span class="c">// on the server!</span>
 495 <span class="c"></span>                <span class="nb">document</span><span class="o">.</span><span class="nx">write</span><span class="o">(</span> <span class="s1">&#39;&lt;iframe id=&quot;yui_hist_iframe&quot; src=&quot;&#39;</span> <span class="o">+</span> <span class="nx">iframeTarget</span> <span class="o">+</span> <span class="s1">&#39;&quot; style=&quot;position:absolute;visibility:hidden;&quot;&gt;&lt;/iframe&gt;&#39;</span> <span class="o">);</span>
 496             <span class="o">}</span>
 497
 498             <span class="c">// We have to wait for the window&#39;s onload handler. Otherwise, our</span>
 499 <span class="c"></span>            <span class="c">// hidden form field will always be empty (i.e. the browser won&#39;t</span>
 500 <span class="c"></span>            <span class="c">// have had enough time to restore the session)</span>
 501 <span class="c"></span>            <span class="nx">YAHOO</span><span class="o">.</span><span class="nx">util</span><span class="o">.</span><span class="nx">Event</span><span class="o">.</span><span class="nx">addListener</span><span class="o">(</span> <span class="nb">window</span><span class="o">,</span> <span class="s2">&quot;load&quot;</span><span class="o">,</span> <span class="nx">_initialize</span> <span class="o">);</span>
 502
 503             <span class="nx">_initialized</span> <span class="o">=</span> <span class="kc">true</span><span class="o">;</span>
 504         <span class="o">},</span>
 505
 506         <span class="c">/**</span>
 507 <span class="c">         * Call this method when you want to store a new entry in the browser&#39;s history.</span>
 508 <span class="c">         *</span>
 509 <span class="c">         * @method navigate</span>
 510 <span class="c">         * @param {string} module Non-empty string representing your module.</span>
 511 <span class="c">         * @param {string} state String representing the new state of the specified module.</span>
 512 <span class="c">         * @return {boolean} Indicates whether the new state was successfully added to the history.</span>
 513 <span class="c">         * @public</span>
 514 <span class="c">         */</span>
 515         <span class="nx">navigate</span> <span class="o">:</span> <span class="k">function</span><span class="o">(</span> <span class="nx">module</span><span class="o">,</span> <span class="nx">state</span> <span class="o">)</span> <span class="o">{</span>
 516             <span class="k">if</span> <span class="o">(</span> <span class="k">typeof</span> <span class="nx">module</span> <span class="o">!=</span> <span class="s2">&quot;string&quot;</span> <span class="o">||</span> <span class="k">typeof</span> <span class="nx">state</span> <span class="o">!=</span> <span class="s2">&quot;string&quot;</span> <span class="o">)</span> <span class="o">{</span>
 517                 <span class="k">throw</span> <span class="k">new</span> <span class="nb">Error</span><span class="o">(</span> <span class="s2">&quot;Missing or invalid argument passed to YAHOO.util.History.navigate&quot;</span> <span class="o">);</span>
 518             <span class="o">}</span>
 519
 520             <span class="k">if</span> <span class="o">(</span> <span class="o">!</span><span class="nx">_bhmReady</span> <span class="o">)</span> <span class="o">{</span>
 521                 <span class="k">throw</span> <span class="k">new</span> <span class="nb">Error</span><span class="o">(</span> <span class="s2">&quot;The Browser History Manager is not initialized&quot;</span> <span class="o">);</span>
 522             <span class="o">}</span>
 523
 524             <span class="k">if</span> <span class="o">(</span> <span class="o">!</span><span class="nx">_modules</span><span class="o">[</span><span class="nx">module</span><span class="o">]</span> <span class="o">)</span> <span class="o">{</span>
 525                 <span class="k">throw</span> <span class="k">new</span> <span class="nb">Error</span><span class="o">(</span> <span class="s2">&quot;The following module has not been registered: &quot;</span> <span class="o">+</span> <span class="nx">module</span> <span class="o">);</span>
 526             <span class="o">}</span>
 527
 528             <span class="c">// Make sure the strings passed in do not contain our separators &quot;,&quot; and &quot;|&quot;</span>
 529 <span class="c"></span>            <span class="nx">module</span> <span class="o">=</span> <span class="nx">escape</span><span class="o">(</span> <span class="nx">module</span> <span class="o">);</span>
 530             <span class="nx">state</span> <span class="o">=</span> <span class="nx">escape</span><span class="o">(</span> <span class="nx">state</span> <span class="o">);</span>
 531
 532             <span class="c">// Generate our new full state string mod1=xxx&amp;mod2=yyy</span>
 533 <span class="c"></span>            <span class="k">var</span> <span class="nx">currentStates</span> <span class="o">=</span> <span class="o">[];</span>
 534             <span class="k">for</span> <span class="o">(</span> <span class="k">var</span> <span class="nx">moduleName</span> <span class="k">in</span> <span class="nx">_modules</span> <span class="o">)</span> <span class="o">{</span>
 535                 <span class="k">var</span> <span class="nx">moduleObj</span> <span class="o">=</span> <span class="nx">_modules</span><span class="o">[</span><span class="nx">moduleName</span><span class="o">];</span>
 536                 <span class="k">var</span> <span class="nx">currentState</span> <span class="o">=</span> <span class="o">(</span> <span class="nx">moduleName</span> <span class="o">==</span> <span class="nx">module</span> <span class="o">)</span> <span class="o">?</span> <span class="nx">state</span> <span class="o">:</span> <span class="nx">moduleObj</span><span class="o">.</span><span class="nx">currentState</span><span class="o">;</span>
 537                 <span class="nx">currentStates</span><span class="o">.</span><span class="nx">push</span><span class="o">(</span> <span class="nx">moduleName</span> <span class="o">+</span> <span class="s2">&quot;=&quot;</span> <span class="o">+</span> <span class="nx">currentState</span> <span class="o">);</span>
 538             <span class="o">}</span>
 539
 540             <span class="k">var</span> <span class="nx">fqstate</span> <span class="o">=</span> <span class="nx">currentStates</span><span class="o">.</span><span class="nx">join</span><span class="o">(</span> <span class="s2">&quot;&amp;&quot;</span> <span class="o">);</span>
 541
 542             <span class="k">if</span> <span class="o">(</span> <span class="nx">_browser</span> <span class="o">==</span> <span class="s2">&quot;msie&quot;</span> <span class="o">)</span> <span class="o">{</span>
 543
 544                 <span class="c">// Add a new entry to the browser&#39;s history...</span>
 545 <span class="c"></span>                <span class="k">var</span> <span class="nx">html</span> <span class="o">=</span> <span class="s1">&#39;&lt;html&gt;&lt;body&gt;&lt;div id=&quot;state&quot;&gt;&#39;</span> <span class="o">+</span> <span class="nx">fqstate</span> <span class="o">+</span> <span class="s1">&#39;&lt;/div&gt;&lt;/body&gt;&lt;/html&gt;&#39;</span><span class="o">;</span>
 546                 <span class="k">try</span> <span class="o">{</span>
 547                     <span class="k">var</span> <span class="nx">doc</span> <span class="o">=</span> <span class="nx">_iframe</span><span class="o">.</span><span class="nx">contentWindow</span><span class="o">.</span><span class="nb">document</span><span class="o">;</span>
 548                     <span class="nx">doc</span><span class="o">.</span><span class="nx">open</span><span class="o">();</span>
 549                     <span class="nx">doc</span><span class="o">.</span><span class="nx">write</span><span class="o">(</span> <span class="nx">html</span> <span class="o">);</span>
 550                     <span class="nx">doc</span><span class="o">.</span><span class="nx">close</span><span class="o">();</span>
 551                 <span class="o">}</span> <span class="k">catch</span> <span class="o">(</span> <span class="nx">e</span> <span class="o">)</span> <span class="o">{</span>
 552                     <span class="k">return</span> <span class="kc">false</span><span class="o">;</span>
 553                 <span class="o">}</span>
 554
 555             <span class="o">}</span> <span class="k">else</span> <span class="o">{</span>
 556
 557                 <span class="c">// Known bug: On Safari 1.x and 2.0, if you have tab browsing</span>
 558 <span class="c"></span>                <span class="c">// enabled, Safari will show an endless loading icon in the</span>
 559 <span class="c"></span>                <span class="c">// tab. This has apparently been fixed in recent WebKit builds.</span>
 560 <span class="c"></span>                <span class="c">// One work around found by Dav Glass is to submit a form that</span>
 561 <span class="c"></span>                <span class="c">// points to the same document. This indeed works on Safari 1.x</span>
 562 <span class="c"></span>                <span class="c">// and 2.0 but creates bigger problems on WebKit. So for now,</span>
 563 <span class="c"></span>                <span class="c">// we&#39;ll consider this an acceptable bug, and hope that Apple</span>
 564 <span class="c"></span>                <span class="c">// comes out with their next version of Safari very soon.</span>
 565 <span class="c"></span>                <span class="nx">top</span><span class="o">.</span><span class="nx">location</span><span class="o">.</span><span class="nx">hash</span> <span class="o">=</span> <span class="nx">fqstate</span><span class="o">;</span>
 566                 <span class="k">if</span> <span class="o">(</span> <span class="nx">_browser</span> <span class="o">==</span> <span class="s2">&quot;safari&quot;</span> <span class="o">)</span> <span class="o">{</span>
 567                     <span class="c">// The following two lines are only useful for Safari 1.x</span>
 568 <span class="c"></span>                    <span class="c">// and 2.0. Recent nightly builds of WebKit do not require</span>
 569 <span class="c"></span>                    <span class="c">// that, but unfortunately, it is not easy to differentiate</span>
 570 <span class="c"></span>                    <span class="c">// between the two. Once Safari 2.0 departs the A-grade</span>
 571 <span class="c"></span>                    <span class="c">// list, we can remove the following two lines...</span>
 572 <span class="c"></span>                    <span class="nx">_fqstates</span><span class="o">[</span><span class="nx">history</span><span class="o">.</span><span class="nx">length</span><span class="o">]</span> <span class="o">=</span> <span class="nx">fqstate</span><span class="o">;</span>
 573                     <span class="nx">_storeStates</span><span class="o">();</span>
 574                 <span class="o">}</span>
 575
 576             <span class="o">}</span>
 577
 578             <span class="k">return</span> <span class="kc">true</span><span class="o">;</span>
 579         <span class="o">},</span>
 580
 581         <span class="c">/**</span>
 582 <span class="c">         * Returns the current state of the specified module.</span>
 583 <span class="c">         *</span>
 584 <span class="c">         * @method getCurrentState</span>
 585 <span class="c">         * @param {string} module Non-empty string representing your module.</span>
 586 <span class="c">         * @return {string} The current state of the specified module.</span>
 587 <span class="c">         * @public</span>
 588 <span class="c">         */</span>
 589         <span class="nx">getCurrentState</span> <span class="o">:</span> <span class="k">function</span><span class="o">(</span> <span class="nx">module</span> <span class="o">)</span> <span class="o">{</span>
 590             <span class="k">if</span> <span class="o">(</span> <span class="k">typeof</span> <span class="nx">module</span> <span class="o">!=</span> <span class="s2">&quot;string&quot;</span> <span class="o">)</span> <span class="o">{</span>
 591                 <span class="k">throw</span> <span class="k">new</span> <span class="nb">Error</span><span class="o">(</span> <span class="s2">&quot;Missing or invalid argument passed to YAHOO.util.History.getCurrentState&quot;</span> <span class="o">);</span>
 592             <span class="o">}</span>
 593
 594             <span class="k">if</span> <span class="o">(</span> <span class="o">!</span><span class="nx">_storageFieldReady</span> <span class="o">)</span> <span class="o">{</span>
 595                 <span class="k">throw</span> <span class="k">new</span> <span class="nb">Error</span><span class="o">(</span> <span class="s2">&quot;The Browser History Manager is not initialized&quot;</span> <span class="o">);</span>
 596             <span class="o">}</span>
 597
 598             <span class="k">var</span> <span class="nx">moduleObj</span> <span class="o">=</span> <span class="nx">_modules</span><span class="o">[</span><span class="nx">module</span><span class="o">];</span>
 599             <span class="k">if</span> <span class="o">(</span> <span class="o">!</span><span class="nx">moduleObj</span> <span class="o">)</span> <span class="o">{</span>
 600                 <span class="k">throw</span> <span class="k">new</span> <span class="nb">Error</span><span class="o">(</span> <span class="s2">&quot;No such registered module: &quot;</span> <span class="o">+</span> <span class="nx">module</span> <span class="o">);</span>
 601             <span class="o">}</span>
 602
 603             <span class="k">return</span> <span class="nx">unescape</span><span class="o">(</span> <span class="nx">moduleObj</span><span class="o">.</span><span class="nx">currentState</span> <span class="o">);</span>
 604         <span class="o">},</span>
 605
 606         <span class="c">/**</span>
 607 <span class="c">         * Returns the state of a module according to the URL fragment</span>
 608 <span class="c">         * identifier. This method is useful to initialize your modules</span>
 609 <span class="c">         * if your application was bookmarked from a particular state.</span>
 610 <span class="c">         *</span>
 611 <span class="c">         * @method getBookmarkedState</span>
 612 <span class="c">         * @param {string} module Non-empty string representing your module.</span>
 613 <span class="c">         * @return {string} The bookmarked state of the specified module.</span>
 614 <span class="c">         * @public</span>
 615 <span class="c">         */</span>
 616         <span class="nx">getBookmarkedState</span> <span class="o">:</span> <span class="k">function</span><span class="o">(</span> <span class="nx">module</span> <span class="o">)</span> <span class="o">{</span>
 617             <span class="k">if</span> <span class="o">(</span> <span class="k">typeof</span> <span class="nx">module</span> <span class="o">!=</span> <span class="s2">&quot;string&quot;</span> <span class="o">)</span> <span class="o">{</span>
 618                 <span class="k">throw</span> <span class="k">new</span> <span class="nb">Error</span><span class="o">(</span> <span class="s2">&quot;Missing or invalid argument passed to YAHOO.util.History.getBookmarkedState&quot;</span> <span class="o">);</span>
 619             <span class="o">}</span>
 620
 621             <span class="k">var</span> <span class="nx">hash</span> <span class="o">=</span> <span class="nx">top</span><span class="o">.</span><span class="nx">location</span><span class="o">.</span><span class="nx">hash</span><span class="o">.</span><span class="nx">substr</span><span class="o">(</span><span class="m">1</span><span class="o">);</span>
 622             <span class="k">var</span> <span class="nx">states</span> <span class="o">=</span> <span class="nx">hash</span><span class="o">.</span><span class="nx">split</span><span class="o">(</span> <span class="s2">&quot;&amp;&quot;</span> <span class="o">);</span>
 623             <span class="k">for</span> <span class="o">(</span> <span class="k">var</span> <span class="nx">idx</span><span class="o">=</span><span class="m">0</span><span class="o">,</span> <span class="nx">len</span><span class="o">=</span><span class="nx">states</span><span class="o">.</span><span class="nx">length</span> <span class="o">;</span> <span class="nx">idx</span><span class="o">&lt;</span><span class="nx">len</span> <span class="o">;</span> <span class="nx">idx</span><span class="o">++</span> <span class="o">)</span> <span class="o">{</span>
 624                 <span class="k">var</span> <span class="nx">tokens</span> <span class="o">=</span> <span class="nx">states</span><span class="o">[</span><span class="nx">idx</span><span class="o">].</span><span class="nx">split</span><span class="o">(</span> <span class="s2">&quot;=&quot;</span> <span class="o">);</span>
 625                 <span class="k">if</span> <span class="o">(</span> <span class="nx">tokens</span><span class="o">.</span><span class="nx">length</span> <span class="o">==</span> <span class="m">2</span> <span class="o">)</span> <span class="o">{</span>
 626                     <span class="k">var</span> <span class="nx">moduleName</span> <span class="o">=</span> <span class="nx">tokens</span><span class="o">[</span><span class="m">0</span><span class="o">];</span>
 627                     <span class="k">if</span> <span class="o">(</span> <span class="nx">moduleName</span> <span class="o">==</span> <span class="nx">module</span> <span class="o">)</span> <span class="o">{</span>
 628                         <span class="k">return</span> <span class="nx">tokens</span><span class="o">[</span><span class="m">1</span><span class="o">];</span>
 629                     <span class="o">}</span>
 630                 <span class="o">}</span>
 631             <span class="o">}</span>
 632
 633             <span class="k">return</span> <span class="kc">null</span><span class="o">;</span>
 634         <span class="o">},</span>
 635
 636         <span class="c">/**</span>
 637 <span class="c">         * Returns the value of the specified query string parameter.</span>
 638 <span class="c">         * This method is not used internally by the Browser History Manager.</span>
 639 <span class="c">         * However, it is provided here as a helper since many applications</span>
 640 <span class="c">         * using the Browser History Manager will want to read the value of</span>
 641 <span class="c">         * url parameters to initialize themselves.</span>
 642 <span class="c">         *</span>
 643 <span class="c">         * @method getQueryStringParameter</span>
 644 <span class="c">         * @param {string} paramName Name of the parameter we want to look up.</span>
 645 <span class="c">         * @param {string} queryString Optional URL to look at. If not specified,</span>
 646 <span class="c">         *     this method uses the URL in the address bar.</span>
 647 <span class="c">         * @return {string} The value of the specified parameter, or null.</span>
 648 <span class="c">         * @public</span>
 649 <span class="c">         */</span>
 650         <span class="nx">getQueryStringParameter</span> <span class="o">:</span> <span class="k">function</span><span class="o">(</span> <span class="nx">paramName</span><span class="o">,</span> <span class="nx">url</span> <span class="o">)</span> <span class="o">{</span>
 651             <span class="nx">url</span> <span class="o">=</span> <span class="nx">url</span> <span class="o">||</span> <span class="nx">top</span><span class="o">.</span><span class="nx">location</span><span class="o">.</span><span class="nx">href</span><span class="o">;</span>
 652             <span class="k">var</span> <span class="nx">idx</span> <span class="o">=</span> <span class="nx">url</span><span class="o">.</span><span class="nx">indexOf</span><span class="o">(</span> <span class="s2">&quot;?&quot;</span> <span class="o">);</span>
 653             <span class="k">var</span> <span class="nx">queryString</span> <span class="o">=</span> <span class="nx">idx</span> <span class="o">&gt;=</span> <span class="m">0</span> <span class="o">?</span> <span class="nx">url</span><span class="o">.</span><span class="nx">substr</span><span class="o">(</span> <span class="nx">idx</span><span class="o">+</span><span class="m">1</span> <span class="o">)</span> <span class="o">:</span> <span class="nx">url</span><span class="o">;</span>
 654             <span class="k">var</span> <span class="nx">params</span> <span class="o">=</span> <span class="nx">queryString</span><span class="o">.</span><span class="nx">split</span><span class="o">(</span> <span class="s2">&quot;&amp;&quot;</span> <span class="o">);</span>
 655             <span class="k">for</span> <span class="o">(</span> <span class="k">var</span> <span class="nx">i</span><span class="o">=</span><span class="m">0</span><span class="o">,</span> <span class="nx">len</span><span class="o">=</span><span class="nx">params</span><span class="o">.</span><span class="nx">length</span> <span class="o">;</span> <span class="nx">i</span><span class="o">&lt;</span><span class="nx">len</span> <span class="o">;</span> <span class="nx">i</span><span class="o">++</span> <span class="o">)</span> <span class="o">{</span>
 656                 <span class="k">var</span> <span class="nx">tokens</span> <span class="o">=</span> <span class="nx">params</span><span class="o">[</span><span class="nx">i</span><span class="o">].</span><span class="nx">split</span><span class="o">(</span> <span class="s2">&quot;=&quot;</span> <span class="o">);</span>
 657                 <span class="k">if</span> <span class="o">(</span> <span class="nx">tokens</span><span class="o">.</span><span class="nx">length</span> <span class="o">&gt;=</span> <span class="m">2</span> <span class="o">)</span> <span class="o">{</span>
 658                     <span class="k">if</span> <span class="o">(</span> <span class="nx">tokens</span><span class="o">[</span><span class="m">0</span><span class="o">]</span> <span class="o">==</span> <span class="nx">paramName</span> <span class="o">)</span> <span class="o">{</span>
 659                         <span class="k">return</span> <span class="nx">tokens</span><span class="o">[</span><span class="m">1</span><span class="o">];</span>
 660                     <span class="o">}</span>
 661                 <span class="o">}</span>
 662             <span class="o">}</span>
 663             <span class="k">return</span> <span class="kc">null</span><span class="o">;</span>
 664         <span class="o">}</span>
 665
 666     <span class="o">};</span>
 667
 668 <span class="o">}</span> <span class="o">)();</span>
 669 </pre></div>
 670                     </div>
 671                         </div>
 672                 </div>
 673                 <div class="yui-b">
 674             <div class="nav">
 675
 676                     <div class="module">
 677                         <h4>Modules</h4>
 678                         <ul class="content">
 679
 680                                 <li class=""><a href="module_animation.html">animation</a></li>
 681
 682                                 <li class=""><a href="module_autocomplete.html">autocomplete</a></li>
 683
 684                                 <li class=""><a href="module_button.html">button</a></li>
 685
 686                                 <li class=""><a href="module_calendar.html">calendar</a></li>
 687
 688                                 <li class=""><a href="module_connection.html">connection</a></li>
 689
 690                                 <li class=""><a href="module_container.html">container</a></li>
 691
 692                                 <li class=""><a href="module_datasource.html">datasource</a></li>
 693
 694                                 <li class=""><a href="module_datatable.html">datatable</a></li>
 695
 696                                 <li class=""><a href="module_dom.html">dom</a></li>
 697
 698                                 <li class=""><a href="module_dragdrop.html">dragdrop</a></li>
 699
 700                                 <li class=""><a href="module_element.html">element</a></li>
 701
 702                                 <li class=""><a href="module_event.html">event</a></li>
 703
 704                                 <li class="selected"><a href="module_history.html">history</a></li>
 705
 706                                 <li class=""><a href="module_logger.html">logger</a></li>
 707
 708                                 <li class=""><a href="module_menu.html">menu</a></li>
 709
 710                                 <li class=""><a href="module_slider.html">slider</a></li>
 711
 712                                 <li class=""><a href="module_tabview.html">tabview</a></li>
 713
 714                                 <li class=""><a href="module_treeview.html">treeview</a></li>
 715
 716                                 <li class=""><a href="module_yahoo.html">yahoo</a></li>
 717                         </ul>
 718                     </div>
 719
 720                     <div class="module">
 721                         <h4>Classes</h4>
 722                         <ul class="content">
 723                                 <li class=""><a href="YAHOO.util.History.html">YAHOO.util.History</a></li>
 724                         </ul>
 725                     </div>
 726
 727                     <div class="module">
 728                         <h4>Files</h4>
 729                         <ul class="content">
 730                                 <li class="selected"><a href="history.js.html">history.js</a></li>
 731                         </ul>
 732                     </div>
 733
 734
 735
 736
 737
 738             </div>
 739                 </div>
 740         </div>
 741         <div id="ft">
 742         <hr />
 743         Copyright &copy; 2007 Yahoo! Inc. All rights reserved.
 744         </div>
 745 </div>
 746 </body>
 747 </html>