I'm looking for javascript libraries and code that can simulate localStorage
on browsers that do not have native support.
Basically, I'd like to code my site using localStorage
to store data and know that it will still work on browsers that don't natively support it. This would mean a library would detect if window.localStorage
exists and use it if it does. If it doesn't exist, then it would create some sort of fallback method of local storage, by creating its own implementation in the window.localStorage
namespace.
So far, I've found these solutions:
I understand that Flash and Silverlight can be used for local storage as well, but haven't found anything on using them as a fallback for standard HTML5 localStorage. Perhaps Google Gears has this capability too?
Please share any related libraries, resources, or code snippets that you've found! I'd be especially interested in pure javascript or jquery-based solutions, but am guessing that is unlikely.
Pure JS based simple localStorage polyfill:
Demo: http://jsfiddle.net/aamir/S4X35/
HTML:
<a href='#' onclick="store.set('foo','bar')">set key: foo, with value: bar</a><br/>
<a href='#' onclick="alert(store.get('foo'))">get key: foo</a><br/>
<a href='#' onclick="store.del('foo')">delete key: foo</a>
JS:
window.store = {
localStoreSupport: function() {
try {
return 'localStorage' in window && window['localStorage'] !== null;
} catch (e) {
return false;
}
},
set: function(name,value,days) {
if (days) {
var date = new Date();
date.setTime(date.getTime()+(days*24*60*60*1000));
var expires = "; expires="+date.toGMTString();
}
else {
var expires = "";
}
if( this.localStoreSupport() ) {
localStorage.setItem(name, value);
}
else {
document.cookie = name+"="+value+expires+"; path=/";
}
},
get: function(name) {
if( this.localStoreSupport() ) {
var ret = localStorage.getItem(name);
//console.log(typeof ret);
switch (ret) {
case 'true':
return true;
case 'false':
return false;
default:
return ret;
}
}
else {
// cookie fallback
/*
* after adding a cookie like
* >> document.cookie = "bar=test; expires=Thu, 14 Jun 2018 13:05:38 GMT; path=/"
* the value of document.cookie may look like
* >> "foo=value; bar=test"
*/
var nameEQ = name + "="; // what we are looking for
var ca = document.cookie.split(';'); // split into separate cookies
for(var i=0;i < ca.length;i++) {
var c = ca[i]; // the current cookie
while (c.charAt(0)==' ') c = c.substring(1,c.length); // remove leading spaces
if (c.indexOf(nameEQ) == 0) { // if it is the searched cookie
var ret = c.substring(nameEQ.length,c.length);
// making "true" and "false" a boolean again.
switch (ret) {
case 'true':
return true;
case 'false':
return false;
default:
return ret;
}
}
}
return null; // no cookie found
}
},
del: function(name) {
if( this.localStoreSupport() ) {
localStorage.removeItem(name);
}
else {
this.set(name,"",-1);
}
}
}