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]

Re: Why does a session variable return to its old value?

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]

Re: Why does a session variable return to its old value?

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]

Re: Why does a session variable return to its old value?

Yes, I do.

[Erwin Moller]

Re: Why does a session variable return to its old value?

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]

Problem solved!

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