Howtos

void init( callback [, options] )
   initiate history object
@param callback <Function>
  This function vill be called with the hash as argument when the hash is updated
@param options <Object> 
   Possible properties 
   {noHash: Boolean, dynamic: Boolean, initReload: Boolean, shorten: Boolean}
   If noHash is true pushState will be used if it is available.
   If dynamic is true a callback is always made even if it is the same hash
   if initReload is true the full page will be reload if the user 
   enters the page with a hash 
   If shorten is true scheme and host will be removed from the hash.
   This is useful when using load directly on href
   Default is true for all.
 
void load ( hash [, title] )
@param hash <String>  -  New hash to update
@param title <String> -  Title to set to the document

/*
 * jQuery history plugin
 * 
 * sample page: http://www.serpere.info/jquery-history-plugin/samples/
 *
 * Copyright (c) 2006-2009 Taku Sano (Mikage Sawatari)
 * Copyright (c) 2010 Takayuki Miwa
 * Licensed under the MIT License:
 *   http://www.opensource.org/licenses/mit-license.php
 *
 * Modified by Lincoln Cooper to add Safari support 
 * and only call the callback once during initialization
 * for msie when no initial hash supplied.
 * 
 * Modified by Van Nhu Nguyen (2011);
 * redesign
 * use hash token #!
 * delay of iframe creation
 * support popstate and hashchange (html5)
 * always load page if dynamic content
 * shorten the hash if it is a full url
 * reload full page using the hash if enter the page with a hash
 * reload the page when user uses back-button 
 * and navigate to the "entered" page if this does not contain a hash 
 */
 
(function($) {
	$.history = (function() {
		var appState = undefined;
		var appCallback = undefined;
		var usePushState = true;
		var dynamic = true;
		var hashHandler = {};
		var interval = 100;
		var support = {};
		var reloadIfInitHash = true;
		var shortenHashPattern = new RegExp("^" + document.location.protocol
				+ "\/\/" + document.location.host, "i");
		var shortenHash = true;
		var encodeHash = false;
		support.needIframe = ($.browser.msie && ($.browser.version < 8 || document.documentMode < 8));
		support.pushState = (window.history && window.history.pushState);
		support.hashChange = ("onhashchange" in window);
		var hashHandlers = {};
 
		hashHandlers.pushState = {
			init : function() {
				appState = this.get();
				if (reloadIfInitHash) {
					var hash = getHash(window);
					if (hash) {
						window.location = hash;
						return;
					}
				}
				$(window).bind("popstate", detectHashChange);
			},
			detect : function() {
				appState = this.get();
				appCallback(appState);
			},
			set : function(hash, title) {
				window.history.pushState(null, title ? title : "", hash);
			},
			get : function() {
				return window.location.href;
			}
		};
 
		hashHandlers.hashChange = {
			init : function() {
				if ((appState = getHash(window))) {
					if (reloadIfInitHash) {
						window.location = appState;
						return;
					}
					appCallback(appState);
				}
				if (support.hashChange) {
					$(window).bind("hashchange", detectHashChange);
				} else {
					setInterval(detectHashChange, interval);
				}
			},
			detect : function() {
				var currentHash = this.get();
				if (currentHash) {
					if (currentHash != appState) {
						appState = currentHash;
						appCallback(currentHash);
					}
				} else if (appState) {
					currentHash = cleanHash(window.location.href);
					appState = currentHash;
					appCallback(currentHash);
				}
			},
			set : function(hash, title) {
				setHash(hash, window);
				if (title) {
					document.title = title;
				}
			},
			get : function() {
				return getHash(window);
			}
		};
 
		hashHandlers.iframe = (function() {
			var id = "__jQuery_history";
			var getIframeDocument = function(write) {
				var doc = $("#" + id)[0].contentWindow.document;
				if (write) {
					doc.open();
					doc.close();
				}
				return doc;
			};
 
			return {
				init : function() {
					var self = null;
					if ((appState = getHash(window))) {
						if (reloadIfInitHash) {
							window.location = appState;
							return;
						}
						self = this;
					}
					/* delay call in case this method called before dom ready */
					$(document).ready(function() {
						var html = '<iframe id="'
							+ id
							+ '" style="display:none" src="javascript:false;" />';
						$("body").prepend(html);
						setInterval(detectHashChange, interval);
						if (appState) {
							appCallback(appState);
							self.set(appState);
						}
					});
				},
				detect : function() {
					var currentHash = this.get();
					var windowHash = getHash(window);
					if (currentHash != appState) {
						appState = currentHash;
						setHash(appState, window);
						appCallback(appState);
					} else if (currentHash != windowHash) {
						appState = windowHash;
						setHash(appState, getIframeDocument(true));
						appCallback(appState);
					}
				},
				set : function(hash, title) {
					setHash(hash, getIframeDocument(true));
					setHash(hash, window);
					if (title) {
						document.title = title;
					}
				},
				get : function() {
					return getHash(getIframeDocument());
				}
			};
		})();
 
		var setHash = function(hash, win) {
			win.location.hash = "!"
					+ (encodeHash ? encodeURIComponent(hash) : hash);
		};
 
		var getHash = function(win) {
			var hash = (win.location.hash).replace(/^#!/, '');
			return $.browser.mozilla ? hash
					: (encodeHash ? decodeURIComponent(hash) : hash);
		};
 
		var cleanHash = function(hash) {
			if (shortenHash) {
				hash = hash.replace(shortenHashPattern, "");
			}
			return hash;
		};
 
		var getHashHandler = function() {
			if (support.needIframe) {
				return hashHandlers.iframe;
			}
			if (support.pushState && usePushState) {
				return hashHandlers.pushState;
			}
			return hashHandlers.hashChange;
		};
 
		var detectHashChange = function() {
			hashHandler.detect();
		};
 
		return {
			init : function(callback, options) {
				if (!$.isFunction(callback)) {
					throw new Error("callback must be a function");
				}
				appCallback = callback;
				if (options) {
					if (typeof options.noHash != 'undefined') {
						usePushState = new Boolean(options.noHash);
					}
					if (typeof options.dynamic != 'undefined') {
						dynamic = new Boolean(options.dynamic);
					}
					if (typeof options.initReload != 'undefined') {
						reloadIfInitHash = new Boolean(options.initReload);
					}
					if (typeof options.shorten != 'undefined') {
						shortenHash = new Boolean(options.shorten);
					}
				}
				hashHandler = getHashHandler();
				hashHandler.init();
			},
			load : function(hash, title) {
				hash = cleanHash(hash);
				if (dynamic || hash != appState) {
					hashHandler.set(hash, title);
					appState = hash;
					appCallback(hash);
				}
			}
		};
	})();
 
})(jQuery);