Recently I’ve been working with a client that wanted me to create a way to sort recipes into different types of food and under different types of dishes. This had me thinking about custom fields where you have meta_key and meta_value for each key. The client also wanted to use this in other scenarios so basically i started thinking it should be sorted on categories as well. The function takes one argument which is the category slug, it will then loop through meta_keys belonging to that category, secondly the meta_values and third each posts matching that specific value.

It’s a whole new take on the custom field principle, since you basically start with the meta_key and not the post itself. Probably not the prettiest code in the world, but it does the job:) And it uses definition lists which is ideal here, below the function there’s a css example aswell.

To use this code, put it in your theme’s functions.php and fetch it in your desired template with

function cfMenu($catID) {
global $wpdb, $post;
$catID = get_cat_id('Mat');

$queryKey = "SELECT DISTINCT meta_key FROM $wpdb->postmeta
    LEFT JOIN $wpdb->term_relationships AS tr ON $wpdb->postmeta.post_id = tr.object_id
    LEFT JOIN $wpdb->term_taxonomy AS tt ON tr.term_taxonomy_id = tt.term_taxonomy_id
    WHERE SUBSTRING(meta_key,1,1) != '_' AND tt.term_id = '$catID'"

    $cfKeys = $wpdb->get_results($queryKey, OBJECT);

    echo '<div id="cfMenu">';
    foreach ($cfKeys as $cfKey) {
        echo '<dl>';
        echo '<h3 class="cfKey">'.$cfKey->meta_key.'</h3>';

        $queryValue = "SELECT DISTINCT meta_value FROM $wpdb->postmeta WHERE meta_key = '$cfKey->meta_key'";
        $cfValues = $wpdb->get_results($queryValue, OBJECT);

        foreach ($cfValues as $cfValue) {
            echo '<dt class="cfValue">'.$cfValue->meta_value.'</dt>';

            $cfPosts = get_posts('meta_value='.$cfValue->meta_value);
            foreach ($cfPosts as $cfPost) {
                $permalink = get_permalink($cfPost->ID);
                echo '<dd class="cfTitle">&raquo; <a href='.$permalink.'>'.$cfPost->post_title.'</a></dd>';
        echo '</dl>';
    echo '</div>';

Here’s a CSS example to get you started

#cfMenu {
    float: left;
    display: inline;

#cfMenu h3 {
    margin: 0 0 0 0;
    padding: 0 0 0 0;

#cfMenu dl {
    float: left;
    width: 230px;
    margin-right: 10px;
    margin-bottom: 20px;

#cfMenu dt {
    font-weight: bold;
    margin: 5px 0 0 0;
    padding: 0 0 0 10px;

#cfMenu dd {
    margin: 0 0 2px 0;
    padding: 0 0 0 10px;
    font-size: 90%;