Set the javascript variable in php session variable

A php session is created at the page load on the server. so there is no way to create the session after the page has loaded.

so you have only one/2 solution if you don't want to use ajax.

solution 1

sess.php

<?php
 session_start();
 $_SESSION['time']=$_GET['time'];
?>

js

head.appendChild(document.createElement('script')).src='sess.php?time='+offset;

note:head is only a reference in this case.

BUT

this is also async.

so again. there is no way to set the session after the page has loaded.

solution 2

preload a image outputted by php with gd that also set's your session. ;)

if you want to know how i can look into it.(this would cause a natural page load & would prolly work also on ie6 )i just don't remember exactly how to preload images before the body does.

I had the same problem some time ago ... i use ajax.

function ajax(a,b,c){ // Url, Callback, just a placeholder
 c=new XMLHttpRequest;
 c.open('GET',a);
 c.onload=b;
 c.send()
}
function LoadThePage(){
 //just some milliseconds passed.
 //session is set
 //load the rest of your page.
 //MOST OF THE TIME this loads faster than the body does.(window.onload)
}
ajax('sess.php?time='+offset,LoadThePage);

at the other side ... now most modern browsers support localstorage.

all phones & the modern browsers.

if i store things like that. why use a php session?

localstorage is made to replace that.

window.localStorage['offset']=((new Date().getTimezoneOffset()) * -1) * 60;