Created
July 20, 2017 01:15
-
-
Save adrian-green/e7251a5854eecb7fd500fc0642e27e75 to your computer and use it in GitHub Desktop.
Simple localStorage function with Cookie fallback for older browsers.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
/** | |
* Simple localStorage with Cookie Fallback | |
* v.1.0.0 | |
* | |
* USAGE: | |
* ---------------------------------------- | |
* Set New / Modify: | |
* store('my_key', 'some_value'); | |
* | |
* Retrieve: | |
* store('my_key'); | |
* | |
* Delete / Remove: | |
* store('my_key', null); | |
*/ | |
var store = function store(key, value) { | |
var lsSupport = false; | |
// Check for native support | |
// broadened for private browsing iOS Safari, per https://gist.github.com/Fluidbyte/4718380#gistcomment-1758829 | |
function storageAvailable(type) { | |
try { | |
var storage = window[type], | |
x = '__storage_test__'; | |
storage.setItem(x, x); | |
setTimeout(function(){ storage.removeItem(x); }, 400); | |
return true; | |
} | |
catch(e) { | |
return false; | |
} | |
} | |
if (storageAvailable('localStorage')) { | |
lsSupport = true; | |
} | |
// If value is detected, set new or modify store | |
if (typeof value !== "undefined" && value !== null) { | |
// Convert object values to JSON | |
if ( typeof value === 'object' ) { | |
value = JSON.stringify(value); | |
} | |
// Set the store | |
if (lsSupport) { // Native support | |
localStorage.setItem(key, value); | |
} else { // Use Cookie | |
createCookie(key, value, 30); | |
} | |
} | |
// No value supplied, return value | |
if (typeof value === "undefined") { | |
// Get value | |
if (lsSupport) { // Native support | |
data = localStorage.getItem(key); | |
} else { // Use cookie | |
data = readCookie(key); | |
} | |
// Try to parse JSON... | |
try { | |
data = JSON.parse(data); | |
} | |
catch(e) { | |
data = data; | |
} | |
return data; | |
} | |
// Null specified, remove store | |
if (value === null) { | |
if (lsSupport) { // Native support | |
localStorage.removeItem(key); | |
} else { // Use cookie | |
createCookie(key, '', -1); | |
} | |
} | |
/** | |
* Creates new cookie or removes cookie with negative expiration | |
* @param key The key or identifier for the store | |
* @param value Contents of the store | |
* @param exp Expiration - creation defaults to 30 days | |
*/ | |
function createCookie(key, value, exp) { | |
var date = new Date(); | |
date.setTime(date.getTime() + (exp * 24 * 60 * 60 * 1000)); | |
var expires = "; expires=" + date.toGMTString(); | |
document.cookie = key + "=" + value + expires + "; path=/"; | |
} | |
/** | |
* Returns contents of cookie | |
* @param key The key or identifier for the store | |
*/ | |
function readCookie(key) { | |
var nameEQ = key + "="; | |
var ca = document.cookie.split(';'); | |
for (var i = 0, max = ca.length; i < max; 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; | |
} | |
}; |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment