2 Copyright (c) 2010, Yahoo! Inc. All rights reserved.
3 Code licensed under the BSD License:
4 http://developer.yahoo.com/yui/license.html
8 YUI.add('history-hash-ie', function(Y) {
11 * Improves IE6/7 support in history-hash by using a hidden iframe to create
12 * entries in IE's browser history. This module is only needed if IE6/7 support
13 * is necessary; it's not needed for any other browser.
16 * @submodule history-hash-ie
20 // Combination of a UA sniff to ensure this is IE (or a browser that wants us to
21 // treat it like IE) and feature detection for native hashchange support (false
22 // for IE < 8 or IE8/9 in IE7 mode).
23 if (Y.UA.ie && !Y.HistoryBase.nativeHashChange) {
25 GlobalEnv = YUI.namespace('Env.HistoryHash'),
26 HistoryHash = Y.HistoryHash,
28 iframe = GlobalEnv._iframe,
30 location = win.location,
34 * Gets the raw (not decoded) current location hash from the IE iframe,
35 * minus the preceding '#' character and the hashPrefix (if one is set).
37 * @method getIframeHash
38 * @return {String} current iframe hash
41 HistoryHash.getIframeHash = function () {
42 if (!iframe || !iframe.contentWindow) {
46 var prefix = HistoryHash.hashPrefix,
47 hash = iframe.contentWindow.location.hash.substr(1);
49 return prefix && hash.indexOf(prefix) === 0 ?
50 hash.replace(prefix, '') : hash;
54 * Updates the history iframe with the specified hash.
56 * @method _updateIframe
57 * @param {String} hash location hash
58 * @param {Boolean} replace (optional) if <code>true</code>, the current
59 * history state will be replaced without adding a new history entry
64 HistoryHash._updateIframe = function (hash, replace) {
65 var iframeDoc = iframe && iframe.contentWindow && iframe.contentWindow.document,
66 iframeLocation = iframeDoc && iframeDoc.location;
68 if (!iframeDoc || !iframeLocation) {
73 iframeDoc.open().close();
76 iframeLocation.replace(hash.charAt(0) === '#' ? hash : '#' + hash);
78 iframeLocation.hash = hash;
82 Do.after(HistoryHash._updateIframe, HistoryHash, 'replaceHash', HistoryHash, true);
85 Y.on('domready', function () {
86 // Create a hidden iframe to store history state, following the
87 // iframe-hiding recommendations from
88 // http://www.paciellogroup.com/blog/?p=604.
90 // This iframe will allow history navigation within the current page
91 // context. After navigating to another page, all but the most
92 // recent history state will be lost.
94 // Earlier versions of the YUI History Utility attempted to work
95 // around this limitation by having the iframe load a static
96 // resource. This workaround was extremely fragile and tended to
97 // break frequently (and silently) since it was entirely dependent
98 // on IE's inconsistent handling of iframe history.
100 // Since this workaround didn't work much of the time anyway and
101 // added significant complexity, it has been removed, and IE6 and 7
102 // now get slightly degraded history support.
104 iframe = GlobalEnv._iframe = Y.Node.getDOMNode(Y.Node.create(
105 '<iframe src="javascript:0" style="display:none" height="0" width="0" tabindex="-1" title="empty"/>'
108 // Append the iframe to the documentElement rather than the body.
109 // Keeping it outside the body prevents scrolling on the initial
110 // page load (hat tip to Ben Alman and jQuery BBQ for this
112 Y.config.doc.documentElement.appendChild(iframe);
114 // Update the iframe with the initial location hash, if any. This
115 // will create an initial history entry that the user can return to
116 // after the state has changed.
117 HistoryHash._updateIframe(HistoryHash.getHash() || '#');
119 // Listen for hashchange events and keep the iframe's hash in sync
120 // with the parent frame's hash.
121 Y.on('hashchange', function (e) {
122 lastUrlHash = e.newHash;
124 if (HistoryHash.getIframeHash() !== lastUrlHash) {
125 HistoryHash._updateIframe(lastUrlHash);
129 // Watch the iframe hash in order to detect back/forward navigation.
130 Y.later(50, null, function () {
131 var iframeHash = HistoryHash.getIframeHash();
133 if (iframeHash !== lastUrlHash) {
134 HistoryHash.setHash(iframeHash);
142 }, '3.3.0' ,{requires:['history-hash', 'node-base']});