3 Copyright 2012 Yahoo! Inc. All rights reserved.
4 Licensed under the BSD License.
5 http://yuilibrary.com/license/
7 YUI.add('history-hash-ie', function(Y) {
10 * Improves IE6/7 support in history-hash by using a hidden iframe to create
11 * entries in IE's browser history. This module is only needed if IE6/7 support
12 * is necessary; it's not needed for any other browser.
15 * @submodule history-hash-ie
19 // Combination of a UA sniff to ensure this is IE (or a browser that wants us to
20 // treat it like IE) and feature detection for native hashchange support (false
21 // for IE < 8 or IE8/9 in IE7 mode).
22 if (Y.UA.ie && !Y.HistoryBase.nativeHashChange) {
24 GlobalEnv = YUI.namespace('Env.HistoryHash'),
25 HistoryHash = Y.HistoryHash,
27 iframe = GlobalEnv._iframe,
31 * Gets the raw (not decoded) current location hash from the IE iframe,
32 * minus the preceding '#' character and the hashPrefix (if one is set).
34 * @method getIframeHash
35 * @return {String} current iframe hash
38 HistoryHash.getIframeHash = function () {
39 if (!iframe || !iframe.contentWindow) {
43 var prefix = HistoryHash.hashPrefix,
44 hash = iframe.contentWindow.location.hash.substr(1);
46 return prefix && hash.indexOf(prefix) === 0 ?
47 hash.replace(prefix, '') : hash;
51 * Updates the history iframe with the specified hash.
53 * @method _updateIframe
54 * @param {String} hash location hash
55 * @param {Boolean} replace (optional) if <code>true</code>, the current
56 * history state will be replaced without adding a new history entry
61 HistoryHash._updateIframe = function (hash, replace) {
62 var iframeDoc = iframe && iframe.contentWindow && iframe.contentWindow.document,
63 iframeLocation = iframeDoc && iframeDoc.location;
65 if (!iframeDoc || !iframeLocation) {
69 Y.log('updating history iframe: ' + hash + ', replace: ' + !!replace, 'info', 'history');
72 iframeLocation.replace(hash.charAt(0) === '#' ? hash : '#' + hash);
74 iframeDoc.open().close();
75 iframeLocation.hash = hash;
79 Do.before(HistoryHash._updateIframe, HistoryHash, 'replaceHash', HistoryHash, true);
82 Y.on('domready', function () {
83 var lastUrlHash = HistoryHash.getHash();
85 // Create a hidden iframe to store history state, following the
86 // iframe-hiding recommendations from
87 // http://www.paciellogroup.com/blog/?p=604.
89 // This iframe will allow history navigation within the current page
90 // context. After navigating to another page, all but the most
91 // recent history state will be lost.
93 // Earlier versions of the YUI History Utility attempted to work
94 // around this limitation by having the iframe load a static
95 // resource. This workaround was extremely fragile and tended to
96 // break frequently (and silently) since it was entirely dependent
97 // on IE's inconsistent handling of iframe history.
99 // Since this workaround didn't work much of the time anyway and
100 // added significant complexity, it has been removed, and IE6 and 7
101 // now get slightly degraded history support.
102 Y.log('creating dynamic history iframe', 'info', 'history');
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(lastUrlHash || '#');
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 Y.log('updating iframe hash to match URL hash', 'info', 'history');
126 HistoryHash._updateIframe(lastUrlHash);
130 // Watch the iframe hash in order to detect back/forward navigation.
131 Y.later(50, null, function () {
132 var iframeHash = HistoryHash.getIframeHash();
134 if (iframeHash !== lastUrlHash) {
135 Y.log('updating URL hash to match iframe hash', 'info', 'history');
136 HistoryHash.setHash(iframeHash);
144 }, '3.5.0' ,{requires:['history-hash', 'node-base']});