page_count.

joeore · October 5th, 2003, 09:57 AM

i have problems with the example of page_count.php in chapter 8. I think that I can resolve this problem with $_SESSION[] variable, but I don't understand how this command work. Can you help me? My code is:

<?php
session_register ("guarda1contatore");
session_register ("guarda2contatore");
session_register ("guarda3contatore");
session_register ("guarda4contatore");
?>
<?php
if (!$guarda1contatore) {$guarda1contatore = 0;}
if (!$guarda2contatore) {$guarda2contatore = 0;}
if (!$guarda3contatore) {$guarda3contatore = 0;}
if (!$guarda4contatore) {$guarda4contatore = 0;}

echo "<html><head><title></title></head><body>";
if ($pagina) {
 echo "ora sei alla pagina $pagina ";
 $GLOBALS["guarda${pagina}contatore"]++;
}
for ($i = 1; $i <= 4; $i++) {
 if ($pagina == $i) {
 echo "<a href=\"$PHP_SELF?" . SID . "pagina=$i\">pagina $i</a>";
 }
 else {
 echo "<a href=\"$PHP_SELF?" . SID . "pagina=$i\">pagina $i<a>";
 }
 echo " : totale visite" . $GLOBALS["guarda${i}contatore"] . " ";
 echo "</body></html>";
}

richard.york · October 5th, 2003, 03:07 PM

Hi Joeore,
The problem relates wholly to register_globals.

First some URLs for you to reference:
Why session_register() is bad:
http://p2p.wrox.com/topic.asp?TOPIC_ID=2052

Nik's FAQ:
http://p2p.wrox.com/archive/beginnin...2002-11/17.asp

And here's a long thread that contains many more urls to reference on both php.net on the wrox forums:
http://p2p.wrox.com/topic.asp?TOPIC_ID=4017

Code:

<?php

# Instead of session_register, use the $_SESSION[] superglobal
# If $_SESSION["..."] is not set, then create it.

if (!isset($_SESSION["guarda1contatore"])) {$_SESSION["guarda1contatore"] = 0;}
if (!isset($_SESSION["guarda2contatore"])) {$_SESSION["guarda2contatore"] = 0;}
if (!isset($_SESSION["guarda3contatore"])) {$_SESSION["guarda3contatore"] = 0;}
if (!isset($_SESSION["guarda4contatore"])) {$_SESSION["guarda4contatore"] = 0;}

echo "<html><head><title></title></head><body>";

# pagina is part of a URL query string and thus accessible via the $_GET superglobal

if (isset($_GET["pagina"])) {

    echo "<span style='font-weight: bold;'>ora sei alla pagina {$_GET["pagina"]}</span><br /><br />";
    $_SESSION["guarda{$_GET["pagina"]}contatore"]++;

}

for ($i = 1; $i <= 4; $i++) {

    if ($_GET["pagina"] == $i) {

        # Use $_SERVER["PHP_SELF"] instead of $PHP_SELF

        echo "<span style='font-weight: bold;'><a href=\"{$_SERVER["PHP_SELF"]}?" . SID . "pagina=$i\">pagina $i</a></span>";

    } else {

        echo "<a href=\"{$_SERVER["PHP_SELF"]}?" . SID . "pagina=$i\">pagina $i</a>";

    }
    echo " : totale visite" . $_SESSION["guarda${i}contatore"] . "<br />";
}
    echo "</body></html>";

?>

I also have a nifty HTML standards compliance FAQ:
http://p2p.wrox.com/topic.asp?TOPIC_ID=4028

Test that out and see what it does. I haven't tested for parse errors.

: )
Rich

:::::::::::::::::::::::::::::::::
Smiling Souls
http://www.smilingsouls.net
:::::::::::::::::::::::::::::::::

richard.york · October 5th, 2003, 03:13 PM

Oh and one more conversion that I missed!

if (isset($_GET["pagina"])) {

echo "ora sei alla pagina {$_GET["pagina"]} ";
$_SESSION["guarda{$_GET["pagina"]}contatore"]++;

}

hth
: )
Rich

:::::::::::::::::::::::::::::::::
Smiling Souls
http://www.smilingsouls.net
:::::::::::::::::::::::::::::::::

richard.york · October 5th, 2003, 03:29 PM

Also it would be helpful to create a default value for $_GET["pagina"]; if none is provided.

if (!isset($_GET["pagina"]))
{
 $_GET["pagina"] = 1;
}

if (isset($_GET["pagina"])) {

 echo "ora sei alla pagina {$_GET["pagina"]} ";
 $_SESSION["guarda{$_GET["pagina"]}contatore"]++;

}

:::::::::::::::::::::::::::::::::
Smiling Souls
http://www.smilingsouls.net
:::::::::::::::::::::::::::::::::

nikolai · October 5th, 2003, 05:28 PM

You're all forgetting the most important step: You need to call session_start() before you can access any session variables.

Take care,

Nik
http://www.bigaction.org/

richard.york · October 6th, 2003, 12:18 AM

Thanks for pointing that out Nik,
I guess when I looked at the post originally I assumed it was just a snippet.. but it is definitely worth mentioning.

Joeore-
When you include the call to session_start() in your code it should appear before all other content, as this function sends out a cookie in the outgoing HTTP response from the server. This means that it needs to be called before any output e.g. echo or print before the opening HTML tag. And the opening PHP delimiter <?php may not have whitespace before it.

http://www.php.net/session_start

: )
Rich

:::::::::::::::::::::::::::::::::
Smiling Souls
http://www.smilingsouls.net
:::::::::::::::::::::::::::::::::