Ghastly Session Nightmare!

knickerlas

Hi all
My last post was not answered, let me simplify:

I start a session on one page and session_register("example");
I then say $example="will it work";

On the next page I echo $example; and I get the answer '0'

Why is this?

any help greatly appreciated

Nick

yelvington

Did you remember session_start()?

From the manual:

"When a visitor accesses your site, PHP will check automatically (if session.auto_start is set to 1) or on your request (explicitly through session_start() or implicitly through session_register()) whether a specific session id has been sent with the request. If this is the case, the prior saved environment is recreated."

knickerlas

I certainly did, even though I believe session_register() will do that for me.
Am I missing anything else obvios? It must be somthing silly as It will not work on windows or unix so I know it's not my DIY config on my PS:

Thanks

Nick

neville

There is nothing wrong with your code ....... maybe you need to check your php.ini file ..maybe!

knickerlas

Thats what I figured.
Thanks Neville, I think I will play around with the rest of my code and see if there is a weird error that's not reporting visibly

nick

brainiac

Have you remembered to carry the session id to the next page ?
ie.

page1.php

<?php
session_start();
$example = "will it work?";
session_register("example");
echo "<a href=\"page2.php?".sid."\">page2.php</a>";
?>

page2.php

<?php
session_start();
echo $example;
?>

You need to carry the session id to the next page if you do not have PHP compiled with trans-sid

knickerlas

I have done this but the good news is that I just knocked up a few pages of very simple nature and they work so I guess it must be an error in the rest of my code.
This is the first time I have tried to use sessions so your help (conformation that it must be somthing else) is much appreciated.

Cheers

Nick

yelvington

Nick, you haven't posted your code, so it's hard to check.

When I pointed out the need for session_start() I should have been more explicit. It must be called on every page, not just the originating page.

Test the following code on your machine.

session.php:
<?
$foo='Doo Dah';
session_register('foo');
?>

<a href="session2.php?<?=SID?>">Click me</a>

session2.php:
<?
session_start();
echo "Foo is $foo";
?>

When you click on the link, you should see

Foo is Doo Dah

If this does not work, then the next step is to examine your php.ini file. Make sure the temp directory exists and is writable by the Web server.

By the way, you do NOT have to echo the SID in the URL if you don't care about the tiny percentage of users who have disabled cookies, and the SID constant will be empty if you have enabled cookies.

knickerlas

Thanks steve, that all seems to be working now I can run a set of pages with an counter using sessions now so I know that works! The confusion continues with a string however.
How do I change the value of a session variable like your $foo ?

Thanks for all your help by the way. I have a couple of decent books on php but I can't seem to get the low down on these damn sessions!

cheers again

Nick

brainiac

To change the value of a variable stored in a session, it needs to be re-registered with the new value into the session.

page1.php

<?php
session_start();
$var = "foo";
session_register("var");
echo "<a href=\"page2.php?".sid."\">page2.php</a>";
?>

page2.php

<?php
session_start();
echo $var;
$var = "bar";
session_register("var");
echo "<a href=\"page3.php?".sid."\">page3.php</a>";
?>

page3.php

<?php
session_start();
echo $var;
?>

goghs

Have you checked your track_vars and register_globals configuration?

Just a hint you can use $HTTP_SESSION_VARS['var'] in stead of $var, thus you need not care value of track_vars and register_globals.

You may need to refer to php manual LXV. Session handling functions.