Rundown on sessions.

FinalMjolnir

Could anyone provide me with one? I used the tutorial at www.phpwizard.net and it helped a bunch. But I can't figure out how to use sessions from one page to another. Could someone explain this for me?

Here's what would basically help.

1) Start the session on page one, and register a variable.
2) Go to another page with no url varaibles, and have it display the variable set in the other file.

Thanks.

IWS

Make sure in the php.ini file session.auto_start is set to 1. Otherwise session_start() would have to be called every page load.

page1:

$_SESSION['var']='foo';

page2:

print_r($_SESSION);

Easy huh?

ednark

maybe a basic explaination will help

err maybe a long rambling explaination will help

the session information is stored on your server.... it is given an id a session_id

when a use enters your site... a session is created for them.... stored in a file by default on the server... and something like a ticket needs to be left behind for the user to claim that session on next page click....

there are two ways to do this....

one: leave a cookie on the users site.... ok if they will let you... each page load, php (behind the scenes) retrieves this ticket from the cookie... finds the file that matches... and loads it for your itchy fingers to use....

two: if the user will not accept any cookies... you need some other way...
ok so you attach to every link on your site a

?PHP_SESS_ID=XXXXXX

and put a

inside every form so that every link clicked on and every form submitted will 'remember' who last was there...

ok all well and good but thats a lot of work... so ok... php decided to do this for you...all you have to do is tell php it is allowed to and it makes this happen.. just behind the scenes so you don't have to worry about it

you do this through the two mechanisms shown by the amazing IWS

either tell php youself with session_start()

or save yourself some carpel tunnel by letting php do it automatically without being asked by setting session_autostart in php.ini

when this happens php will set up a space for your session information

with register_globals off this is the $_SESSION array with register_globals on this is the $HTTP_SESSION_VARS array

now you just use it and behind the scenes php takes care of where to put this infromation between page loads... and takes care of managing who has what ticket to what session file...

now after reading tutorials and using the print_r() mentioned by IWS and reading my explaination... does it all make sense yet?

FinalMjolnir

Well... You didn't really make too much sense. So I'll just give you the code I was using.

File one:

session_start();
$session_userid = $userid;
session_register("session_userid");

File two (I've tried the variable as $session_userid also and it doesn't work):

if (!isset($_SESSION['session_userid'])) {
  echo ('
    | <a href="'.$mb_basedir.'login.php">Login</a>
  ');
}
else {
  echo ('
    | Logged in
  ');
}

There's is no session start on the second page, but how do I tell it what session ID to use?

Weedpacket

Originally posted by FinalMjolnir

There's is no session start on the second page, but how do I tell it what session ID to use?

1) You do need the session_start().
2) You don't tell it what session ID to use - you don't know what the session ID is; the browser does and it supplies it when it makes its request.

FinalMjolnir

I want it to use the same session as was started on Page One...

ednark

you are missing the point...

just call session_start() on both pages

php will take care of figuring out the specific session_id for you...

you are not supposed/expected to know the id for any reason... the only thing you are expected to do is tell php that you do want to use a session on this page

php will make sure it is the same session on both pages

it's that simple

and if you are using register_globals set to Off.... you can ditch the session_register() call all together

php will make sure $_SESSION exsists on each page.... and will make sure any changes to it stay across pages

one.php

session_start()
$_SESSION['name'] = 'ednark';
print '<a href="two.php">two</a>

two.php

session_start()
print $_SESSION['name'];
/// prints 'ednark'
print '<a href="one.php">one</a>

FinalMjolnir

I know I'm missing the point, lol. I've just got basically the same code on two pages and it's not working. How do functions effect sessions? Because I'm using very function heavy code and could that be messing up the session variables?

[EDIT]
Whelp, I tried not using session_register("session_userid") and changed it to $_SESSION['session_userid'] = $userid; and it works now...

ednark

understood...if you already knew this you wouldn't be here

$_SESSION is special
and it should exist anywhere in your code

if you are unsure about that, do a
print_r() on is where you are susupicious, and see what happens...

functions should operate on the $_SESSION array just as any other code

you should have no need ot pass the $SESSION array anywhere as it should already exsist there... and passing noramally means makeing a copy of.. so if you pass $SESSION to a function, and edit it, the changes will not be reflected in the real $_SESSION that gets preserved across the page...

does this make more sense now?

FinalMjolnir

Yeah, I get it now. Look at the edit in my other post.

leatherback

Hi ednark,

If you are still reading this thread: Could you please (try to) help me solve (or understand my error) on this:

PHP Builder Community Forums > PHP Help > Newbies > session & non-administrator on server

Thanks!
'
J.

Weedpacket

Originally posted by FinalMjolnir
Yeah, I get it now. Look at the edit in my other post.

Rereading my part 2), I guess I was a bit short (so I've been busy: singal/noise ratio, you know...)

If the browser has a session_id stored on it and it sends a request to the server, it sends the session_id along as well. When session_start() is called, it tells PHP to look to see if the request had a session_id attached, and if it does, it retrieves the stored session data. (If there was no session_id in the request, then that's a good excuse to create one and send it back to the browser with the response.)

The important thing to remember about the http protocol is that the server has no memory from one request to the next of who's requesting what (its a so-called stateless protocol). So if you do want to track clients from request to request, the client has to be able to identify itself in some way. Sessions achieve this by having the server send a session_id to the client, saying in effect "wear this when you come in for something, so's I can recognise you".