Home Man
Search
Today's Posts
Register

Javascript, Javascript libs and toolkits, LAMP, Apache, MySQL, HTML, and other web coding posts.

Using Javascript sessionStorage versus Cookies

Tags
cookies, html5, javascript, localstorage, sessions, sessionstorage

Login to Reply

 
Thread Tools Search this Thread
# 1  
Old 1 Week Ago
Using Javascript sessionStorage versus Cookies

In browsers that support HTML5 we can use sessionStorage in Javascript instead of Cookies to set variables that need to be persistent per session.

For example, in this PHP code for the forums, we can do something like the following:

Code:
$localStorage  = '<script>'; 
$sessionStorage .= 'sessionStorage.setItem("showMember","true");'; 
$sessionStorage .= 'sessionStorage.setItem("thisScript","'.THIS_SCRIPT.'");'; 
$sessionStorage .= 'sessionStorage.setItem("styleId","'.STYLEID.'");'; 
$sessionStorage .= 'sessionStorage.setItem("userId","'.USER_ID.'");'; 
$sessionStorage .= '</script>'."\n";

And of course insert the code above in our HTML template somewhere (like the header) and then use the sessionStorage vars (from our server side PHP code) in our Javascript and jQuery scripts.

The main difference is that the data stored in sessionStorage is not sent back to the server per request (like in Cookies) and the storage limit is much bigger for sessionStorage than for Cookies.

In HTML5 sessionStorage differs primarily from localStorage in that localStorage does not go away even after the tab or browser is closed. It can of course be cleared with the localStorage.clear() method or cleared in browser by the user.

Here is a small example of how we use sessionStorage:

Code:
<script>
$(function() {
  if(sessionStorage.showMember && sessionStorage.thisScript !='showpost')
  {
    var text =  document.getElementById("neo-notice").innerHTML;
    var unread = text.match(/>0<\/strong>/g);
     if(!unread){
       $('.avatarbadge').show();
     }
      else {  $('.avatarbadge').hide();}
  }
});
</script>

In the code above, we are trapping an error because of some strange bug on one of our pages when we show notifications to users. Otherwise, we check for messages unread and if so, we display the badge.

Here is another example:

Code:
<script>
$(document).ready(function() {
if(sessionStorage.showMember && sessionStorage.thisScript != 'showpost')
 {
  if ($('#myMemberPanel').length > 0) {
  document.getElementById("myMemberPanel").style.width = "0px";
 }
}
});
</script>

In the above example, we trap the same error (on the 'showpost' pages which we have deprecated) and otherwise we set the initial width of the memberPanel to 0px;

These are fairly trivial examples, but they do help illustrate how easy it it is in HTML5 to use localStorage and sessionStorage in Javascript.

Last edited by Don Cragun; 1 Week Ago at 01:58 PM.. Reason: Move "<script>" inside CODE tags.
Login to Reply

« Previous Thread | Next Thread »
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

More UNIX and Linux Forum Topics You Might Find Helpful
Thread Thread Starter Forum Replies Last Post
Cookies in UNIX rvinodh3 UNIX for Dummies Questions & Answers 1 03-19-2014 09:51 AM
Awk Versus Cut jaysunn Shell Programming and Scripting 6 12-29-2009 09:36 AM
PHP Help - Delete cookies and redirect back to referrer Adrnalnrsh Web Programming 0 11-19-2009 12:22 PM
cpio versus cp fredao UNIX for Advanced & Expert Users 1 09-17-2007 02:05 PM
AIX versus Networks rawatmohinder AIX 5 05-23-2006 05:54 AM
<LF> versus <CR>/<LF> jerardfjay Shell Programming and Scripting 1 10-20-2005 06:09 PM
CTRL+H versus ^? versus BACKSPACE alan UNIX for Dummies Questions & Answers 3 07-23-2003 01:08 PM


All times are GMT -4. The time now is 07:48 AM.

Unix & Linux Forums Content Copyrightę1993-2018. All Rights Reserved.
UNIX.COM Login
Username:
Password:  
Show Password