//* Paul Snowden's JavaScript style switcher from http://www.alistapart.com/articles/alternate/ */ //* Data-driven javascript - the following array holds details of the stylesheet options: //* the CSS id of the selector button and title attribute of the corresponding CSS file as declared in the HTML //* This approach allows a simple method of changing or adding options without intervention in the javascript code //* NOTE: row(0) of the array is effectively just headings and is ignored in the code that follows var param_styleOptions = [ ['**button CSS ID**', '**CSS stylesheet title**'], ['sidebar-show', 'sidebar-show'], ['sidebar-hide', 'sidebar-hide'] ]; //* function to set the active style sheet */ function setActiveStyleSheet(title) { var i, a, main; for(i=0; (a = document.getElementsByTagName("link")[i]); i++) { if(a.getAttribute("rel").indexOf("style") != -1 && a.getAttribute("title")) { a.disabled = true; if(a.getAttribute("title") == title) a.disabled = false; } } } //* function to determine the currently active style sheet */ function getActiveStyleSheet() { var i, a; for(i=0; (a = document.getElementsByTagName("link")[i]); i++) { if(a.getAttribute("rel").indexOf("style") != -1 && a.getAttribute("title") && !a.disabled ) return a.getAttribute("title"); } return null; } //* function to get the required style sheet */ function getPreferredStyleSheet() { var i, a; for(i=0; (a = document.getElementsByTagName("link")[i]); i++) { if(a.getAttribute("rel").indexOf("style") != -1 && a.getAttribute("rel").indexOf("alt") == -1 && a.getAttribute("title") ) return a.getAttribute("title"); } return null; } //* function to create a cookie to store the active stylesheet so that it can be used in all pages during the current session */ function createCookie(name,value,days) { if (days) { var date = new Date(); date.setTime(date.getTime()+(days*24*60*60*1000)); var expires = "; expires="+date.toGMTString(); } else expires = ""; document.cookie = name+"="+value+expires+"; path=/"; } //* function to read the cookie if present and determine the required style sheet */ function readCookie(name) { var nameEQ = name + "="; var ca = document.cookie.split(';'); for(var i=0;i < ca.length;i++) { var c = ca[i]; while (c.charAt(0)==' ') c = c.substring(1,c.length); if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length); } return null; } //* detect when a page is loaded and determine the preferred style sheet from any existing cookie */ window.onload = function(e) { var cookie = readCookie("style"); var title = cookie ? cookie : getPreferredStyleSheet(); setActiveStyleSheet(title); } //* detect when the current page is unloaded and cause the current stylesheet to be stored in a cookie, which expires in 365 days */ window.onunload = function(e) { var title = getActiveStyleSheet(); createCookie("style", title, 365); } //* */ var cookie = readCookie("style"); var title = cookie ? cookie : getPreferredStyleSheet(); setActiveStyleSheet(title); //* function to set up the required clickhandlers */ function styleButtonClickHandler(styleId, cssFile) { var styleChoice = { init: function() { var link = document.getElementById(styleId); // alert("clickHandler active for CSS id: "+styleId+", "+cssFile); link.onclick = styleChoice.clickHandler; }, clickHandler: function() { setActiveStyleSheet(cssFile); return false; } }; Core.start(styleChoice); } //* cycle throught the available options and call the clickhandler setting function for each */ for (var i = 1; i < param_styleOptions.length; i++) { var nextStyle = param_styleOptions[i]; var styleId = nextStyle[0]; var cssFile = nextStyle[1]; styleButtonClickHandler(styleId, cssFile); }