CookieStorage.js

/* * CookieStorage.js * This class implements the Storage API that localStorage and sessionStorage * do, but implements it on top of HTTP Cookies. */ function CookieStorage(maxage, path) { // Arguments specify lifetime and scope // Get an object that holds all cookies var cookies = (function() { // The getCookies() function shown earlier var cookies = {}; // The object we will return var all = document.cookie; // Get all cookies in one big string if (all === "") // If the property is the empty string return cookies; // return an empty object var list = all.split("; "); // Split into individual name=value pairs for(var i = 0; i < list.length; i++) { // For each cookie var cookie = list[i]; var p = cookie.indexOf("="); // Find the first = sign var name = cookie.substring(0,p); // Get cookie name var value = cookie.substring(p+1); // Get cookie value value = decodeURIComponent(value); // Decode the value cookies[name] = value; // Store name and value } return cookies; }()); // Collect the cookie names in an array var keys = []; for(var key in cookies) keys.push(key); // Now define the public properties and methods of the Storage API // The number of stored cookies this.length = keys.length; // Return the name of the nth cookie, or null if n is out of range this.key = function(n) { if (n < 0 || n >= keys.length) return null; return keys[n]; }; // Return the value of the named cookie, or null. this.getItem = function(name) { return cookies[name] || null; }; // Store a value this.setItem = function(key, value) { if (!(key in cookies)) { // If no existing cookie with this name keys.push(key); // Add key to the array of keys this.length++; // And increment the length } // Store this name/value pair in the set of cookies. cookies[key] = value; // Now actually set the cookie. // First encode value and create a name=encoded-value string var cookie = key + "=" + encodeURIComponent(value); // Add cookie attributes to that string if (maxage) cookie += "; max-age=" + maxage; if (path) cookie += "; path=" + path; // Set the cookie through the magic document.cookie property document.cookie = cookie; }; // Remove the specified cookie this.removeItem = function(key) { if (!(key in cookies)) return; // If it doesn't exist, do nothing // Delete the cookie from our internal set of cookies delete cookies[key]; // And remove the key from the array of names, too. // This would be easier with the ES5 array indexOf() method. for(var i = 0; i < keys.length; i++) { // Loop through all keys if (keys[i] === key) { // When we find the one we want keys.splice(i,1); // Remove it from the array. break; } } this.length--; // Decrement cookie length // Finally actually delete the cookie by giving it an empty value // and an immediate expiration date. document.cookie = key + "=; max-age=0"; }; // Remove all cookies this.clear = function() { // Loop through the keys, removing the cookies for(var i = 0; i < keys.length; i++) document.cookie = keys[i] + "=; max-age=0"; // Reset our internal state cookies = {}; keys = []; this.length = 0; }; }