PHP Cookie: Clueless, Please Help

[calfellows]

Hello,

I am wondering if there is a way for me to use a php cookie
to memorize the template theme HTML (not css).

Right now, I have it set to grab theme=1 by default, but if
I call a theme using get (index.php?theme=4), I need a cookie
to remember the queried theme instead. My mind cannot
fathom the engineering needed to do this. Can anyone please
help?

You can see what I have at the link below, the pull downs
are javascript, but php seems most appropriate since I''m
using gueries for the theme. The js pulldown does a query,
and so PHP needs to see any query and build cookie. http://tinyurl.com/55klxr

Please and thanks,
Cal

<?php
/* 
Front Controller Script: 
NOTE PATTERN: index.php?theme=1
*/

/* Default Theme Template (unless otherwise specified) */ 
$pgtheme = '4'; /* 1, 4, OR 24 */

/* THEME: Include or Static */
$gttheme = isset( $_GET['theme'] ) ? $_GET['theme'] : $pgtheme;
$theme=('theme'.$gttheme.'.php'); 

/* THEME INCLUDE FOR FILL/FORMATTING: All similarly formatted */
include ($theme); // returns html with variable and includes
?>

[domainregistrar]

You may use cookies to set / store user preferences and later retrieve the stored value from cookie to set user theme / template.

Here is a pseudocode ...
setcookie('template', '1') to set template with value 1
You may retrieve the value with
if (isset($_COOKIE['cookie'])) {
//Do something here ...
}

thx
GS

[Jake Arkinstall]

<?php 
/* 
Front Controller Script: 
NOTE PATTERN: index.php?theme=1 
*/ 

/* Default Theme Template (unless otherwise specified) */ 
$pgtheme = '4'; /* 1, 4, OR 24 */ 
if(isset($_GET['theme']) && in_array(array(1, 2, 24), $_GET['theme'])){ //if a theme is set and in the allowed array
    $pgtheme = $_GET['theme']; //set the theme to the requested theme
}else if(isset($_COOKIE['theme'])){ //else if a cookie exists
    $pgtheme = $_COOKIE['theme']; //set the theme to it
}
setcookie ('theme' , $pgtheme, time() + (6 * 30 * 24 * 60 * 60), '/'); //set the cookie for approx 6 months
/* THEME: Include or Static */ 
$theme= 'theme'.$pgtheme.'.php';

/* THEME INCLUDE FOR FILL/FORMATTING: All similarly formatted */ 
include ($theme); // returns html with variable and includes 
?>

[calfellows]

Arkinstall,

Thank you very much for your input and assistance. I do appreciate it.

I'm now with error, "wrong data type in second argument on line 2, the if/else statement. Anyone see the problem? Line one sets default $pgtheme, but if there's a query, it needs to override and set a cookie, which is why I was originally using $gttheme to represent the final.
Many Thanks,
Cal

<?php
$pgtheme = '4'; /* 1, 4, OR 24: DEFAULT THEME IF NONE SPECIFIED */ 
if(isset($_GET['theme']) && in_array(array(1, 2, 24), $_GET['theme'])){ //if a theme is set and in the allowed array 
    $pgtheme = $_GET['theme']; //set the theme to the requested theme 
}else if(isset($_COOKIE['theme'])){ //else if a cookie exists 
    $pgtheme = $_COOKIE['theme']; //set the theme to it 
} 
setcookie ('theme' , $pgtheme, time() + (6 * 30 * 24 * 60 * 60), '/'); //set the cookie for approx 6 months 
/* THEME: Include or Static */ 
$theme= 'theme'.$pgtheme.'.php'; 

/* THEME INCLUDE FOR FILL/FORMATTING: All similarly formatted */ 
include ($theme); // returns html with variable and includes ?>

[Jake Arkinstall]

Ah, my bad, got the params mixed around in in_array (PHP's so lousy when it comes to keeping needle and haystack in the same order):

if(isset($_GET['theme']) && in_array($_GET['theme'], array('1', '2', '24'))){ 

[calfellows]

ARKINSTALL,

You did it again. Works like a charm. Thank You!.
It's getting cool now, all of those buttons.
http://tinyurl.com/55klxr

Is it an easy task to set it for random theme
within the same array?

I've never been able to cookie the font-family js
switcher that I posted here in March. I've never
found a working one online. The code works, but no
cookie. Anyone?
http://www.sitepoint.com/forums/showthread.php?t=545123

Thanks again Ark,
Cal