WordPress MU

I've spent the day working in order to get category exclusion for the homepage loop working.

I have managed to get the backend UI working, so that a client can choose which categories to exclude in the theme admin panel.

I checked the db options table and sure enough the data is being saved properly.

example from the database sites options table -- all cats are either true or false like below

zoo_cat_box_4 true
--user checked box to exclude cat#4 in the admin

zoo_cat_box_5 true
--user checked box to exclude cat#5 in the admin

zoo_cat_box_6 false
--user did not check the box for cat#6 so it should show

That means I have the db setup properly.
(true next to cats that are excluded, false next to those not checked)

** 4,5,6 are the actual category id#'s, so that part is correct. I have an entry in the db for each category id#

Where I am stuck is the function to display this on the homepage.

Right now I have this function added to my themes functions file.

// Custom Homepage loop
function get_exclude_categories_loop() {
    $include = array();
    $counter = 0;
    $cats = get_categories('hide_empty=0');

    foreach ($cats as $cat) {

        $counter++;

        if ( get_option( "zoo_cat_box_".$cat->cat_ID ) == 'true') {

                $excludecats[] = $cat->cat_ID;
            }
        }
        if(!empty($excludecats)){
        $excludecats = implode(',',$excludecats);
        }
    return $excludecats;

}

On my homepage I am using this code to call the loop:

<?php
query_posts(array('category__not_in' => array(get_exclude_categories_loop))); ?>
<?php if (have_posts()) : while (have_posts()) : the_post();
?>

Now if I change the homepage loop code "get_exclude_categories_loop" and replace that with numbers like 4,5,6 then categories 4,5,6 do not show up.

This means either my get_exclude_categories_loop function above is screwed up, or I'm not calling it correctly in the loop.

Well I know I am REALLY close to getting this right, but 1/2 a day later I'm stuck...

hoping a Ninja will recognize my mistake and let me know what I did wrong and why... (always trying to learn)

thanks

p.s.
How do I go about using var_dump on my get_exclude_categories_loop function to see what it's returning?

I've tried everything I can think of to see what the function is spitting out, but can't get the hang of var_dump. Otherwise I would know if it's my function or how I am calling it in my home.php file...

You function returns a array but then you do

array(get_exclude_categories_loop)

which means you've wrapped your array inside another.

Try

query_posts(array('category__not_in' => get_exclude_categories_loop() )); ?>

To use var_dump you'd just put var_dump(get_exclude_categories_loop());

or use a set

$wp_query->set('cat', '-14,-1172,-867'); // replace 2nd parameter with array
$wp_query->set('posts_per_page', 10);
$posts = $wp_query->get_posts();
include ($includedirectory . "loop.php");

Thank you guys, it's working now.

Mostly it turns out that I was confused by the codex documentation when they gave the example:
query_posts(array('category__not_in' => array(2,6)));

That lead me to believe that I needed a comma separated list and not an array. With a few changes, all works perfectly now.