/* unFocusHistoryKeeper, version 0.8.3 (alpha) (2005/07/29) Copyright: 2005, Kevin Newman (http://www.unfocus.com/Projects/HistoryKeeper/) License: http://creativecommons.org/licenses/LGPL/2.1/ */ if (!window.unFocusHistoryKeeper) new function() { window.unFocusHistoryKeeper = this; // private variables var _pollInterval = 200; var _listeners = []; // there has been much debate over whether this is appropriate as an array on comp.lang.javascript :-) var _currentHash = _GetHash(); // do constructor type stuff here // :TODO: add alternative hash update detection methods if one is available (anybody?) // :NOTE: this method doesn't work to detect changes in IE 5.5 or 6.0 when the back button is // pressed (location and location.hash are not updated - even when an anchor is added like in IE 5.0) if (setInterval) var _intervalID = setInterval(_CheckHash, _pollInterval); // private methods function _GetHash() { return location.hash.substring(1); }; function _SetHash($newHash) { window.location.hash = $newHash; }; function _CheckHash() { var $newHash = _GetHash(); if (_currentHash != $newHash) { _currentHash = $newHash; _NotifyListeners($newHash); } }; function _NotifyListeners($newHash) { for (var i = _listeners.length; -1 < --i;) _listeners[i].unFocusHistoryUpdate($newHash); }; // privileged methods this.AddListener = function($obj) { // consider throwing exceptions here (can't have NS4 compat then) if (!$obj.unFocusHistoryUpdate) return false; // add an exception here // check if this is already in here for (var i = _listeners.length; -1 < --i;) if (_listeners[i] == $obj) return false; // add an exception here? _listeners.push($obj); // do init if ($obj.unFocusHistoryLoad) $obj.unFocusHistoryLoad(_currentHash); return true; }; this.RemoveListener = function($obj) { for (var i = _listeners.length; -1 < --i;) { if (_listeners[i] == $obj) { _listeners.splice(i,1); break; } } }; this.AddBookmark = function($newHash) { // adds history and bookmark hash _currentHash = $newHash; _SetHash($newHash); _NotifyListeners($newHash); }; /*************************** * Browser specific patches * ***************************/ // do browser sniffing, fixes bugs that can't be detected through feature sniffing if (/MSIE/.test(navigator.userAgent) && !/Opera/.test(navigator.userAgent)) { // overwrite the old functions (gotta love javascript :-) ) // IE 5.5 and 6.0 (I'm going to assume IE 7.x too - will test August 3) need the iframe method, since adding a hash makes no history if (navigator.appVersion.match(/MSIE (\d\.\d+)/)[1] >= 5.5) { // setup history IFrame var $historyFrame = false; this.AddBookmark = function($newHash) { // adds history and bookmark hash _currentHash = $newHash; _CreateHistoryHTML($newHash, true); }; this._NotifyListeners = function($newHash) { // the first time this is called, it shouldn't notify, so it instead replaces itself with a version that will notify this._NotifyListeners = function($newHash) { _currentHash = $newHash; _SetHash($newHash); _NotifyListeners($newHash); }; }; function _CreateHistoryHTML($newHash) { $historyFrame.document.open('text/html'); $historyFrame.document.write(''); $historyFrame.document.close(); }; // set up the History Frame, for AddHistory method function _SetUpHistoryFrame() { if (!window.frames['unFocusHistoryFrame']) { $historyFrame = document.createElement("iframe"); $historyFrame.name = 'unFocusHistoryFrame'; $historyFrame.id = 'unFocusHistoryFrame'; $historyFrame.style.position = 'absolute'; $historyFrame.style.top = '-900px'; //$historyFrame.runtimeStyle.display = 'none'; document.body.appendChild($historyFrame); } // reset the reference to the frame using the frames array - for some reason // the other reference can't be used with document.open $historyFrame = window.frames[window.frames.length-1]; // create root frame for the furthest back state _CreateHistoryHTML(_currentHash); }; window.attachEvent('onload', _SetUpHistoryFrame); } else { // IE 5.0 needs an anchor before it will take a new hash value this.AddBookmark = function($newHash) { // adds history and bookmark hash _currentHash = $newHash; _CreateAnchor($newHash); _SetHash($newHash); _NotifyListeners($newHash); }; function _CreateAnchor($newHash) { var $anchor = document.createElement('a'); $anchor.setAttribute('name',$newHash); if (/MSIE/.test(navigator.userAgent)) $anchor = document.createElement(''); $anchor.style.position = 'absolute'; $anchor.style.left = document.body.scrollLeft; $anchor.style.top = document.body.scrollTop; //$anchor.innerHTML = $newHash; document.body.appendChild($anchor); }; } } };