Why does a session variable return to its old value?

[damezumari]

I have a problem in my application I have not been able to reproduce
completely with a simpler set of files. I know this is a crime, but
here goes:

In a file I have these instructions:

echo 'before: '.$_SESSION['classtitle'].'<br />';
require_once 'test3.php';
echo 'after: '.$_SESSION['classtitle'].'<br />';
echo '<p><a href="test.php">test</a></p>';

They display on the screen:

before: b
test3 before: b
test3 after: a
after: a

So far, so good. But, when I click the link to test.php, this is
displayed:

test: b

I don't understand how $_SESSION['classtitle'] goes back to its old
value.

Here are test3.php and test.php:

test3.php:
<?php
session_start();
echo 'test3 before: '.$_SESSION['classtitle'].'<br />';
$_SESSION['classtitle'] = 'a';
echo 'test3 after: '.$_SESSION['classtitle'].'<br />';
?>

<?php
session_start();
echo 'test: '.$_SESSION['classtitle'].'<br />';
?>

Can anyone point me in the right direction, please?

Regards,

Jan Nordgreen

[damezumari]

I have just discovered that the problem can be simplified a bit;
test3.php is not needed.

$_SESSION['classtitle'] = 'b';
echo 'main: '.$_SESSION['classtitle'].'<br />';
unset($_SESSION['classtitle']);
echo '<p><a href="test.php">test</a></p>';

This displays:

main: b

But when I click the link to test.php I get:

test: a

Conclusion: $_SESSION['classtitle'] in test.php is not the same as in
the main program. How come?

Regards,

Jan Nordgreen

[Robin]

damezumari wrote:

I have just discovered that the problem can be simplified a bit;
test3.php is not needed.

$_SESSION['classtitle'] = 'b';
echo 'main: '.$_SESSION['classtitle'].'<br />';
unset($_SESSION['classtitle']);
echo '<p><a href="test.php">test</a></p>';

This displays:

main: b

But when I click the link to test.php I get:

test: a

Conclusion: $_SESSION['classtitle'] in test.php is not the same as in
the main program. How come?

Regards,

Jan Nordgreen

Are you calling session_start() at the top of the page that links to
test.php?

Robin

[damezumari]

Yes, I do.

[Erwin Moller]

damezumari wrote:

I have just discovered that the problem can be simplified a bit;
test3.php is not needed.

$_SESSION['classtitle'] = 'b';
echo 'main: '.$_SESSION['classtitle'].'<br />';
unset($_SESSION['classtitle']);
echo '<p><a href="test.php">test</a></p>';

This displays:

main: b

But when I click the link to test.php I get:

test: a

Conclusion: $_SESSION['classtitle'] in test.php is not the same as in
the main program. How come?

Regards,

Jan Nordgreen

Hi,

This shouldn't happen.
You unset that sessionvar, so it should be gone on test.php, and thus
produce an error.
You *DO* have errorreporting on I hope?
If unsure, inspect your php.ini, or put this above all your files:
error_reporting(E_ALL);

If that doesn't enlighten you in any way: Why don't you post both files here
so we can inspect them?
(Preferably your simplified versions)

Regards,
Erwin Moller

[damezumari]

Yes, error checking is on in php.ini.

I have found my error:

Further down in the main program I had a new assignment to
$_SESSION['classtitle']:

$_SESSION['classtitle'] = 'b';
echo 'main: '.$_SESSION['classtitle'].'<br />';
unset($_SESSION['classtitle']);
echo '<p><a href="test.php">test</a></p>';
...
...
...
$_SESSION['classtitle'] = a;

It is of course the last assignment to $_SESSION['classtitle'] in the
main program that is in effect when the user clicks the link to
test.php, not the last assignment before the link.

Silly me! :)

Thanks for the responses!

Regards,

Jan Nordgreen