Exclude Subcategories in a Loop
This code snippet excludes the subcategories in a loop. Just insert the code in your functions.php of your theme or in a Plugin and you are done.
if ( !function_exists('fb_filter_child_cats') ) {
function fb_filter_child_cats( $cats ) {
global $wp_query, $wpdb;
if ( is_category() ) {
// get children ID's
if ( $excludes = get_categories( "child_of=" . $wp_query->get('cat') ) ) {
// set array with ID's
foreach ( $excludes as $key => $value ) {
$exclude[] = $value->cat_ID;
}
}
// remove child cats
if ( isset($exclude) && is_array($exclude) ) {
$cats .= " AND " . $wpdb->prefix . "term_taxonomy.term_id NOT IN (" . implode(",", $exclude) . ") ";
}
}
return $cats;
}
if ( !is_admin() ) {
add_filter( 'posts_where', 'fb_filter_child_cats' );
}
}
Update for WP 3.1 and higher:
if ( !function_exists('fb_filter_child_cats') ) {
function fb_filter_child_cats( $cats ) {
global $wp_query, $wpdb;
if ( is_category() ) {
// get children ID's
if ( $excludes = get_categories( "child_of=" . $wp_query->get('cat') ) ) {
// set array with ID's
foreach ( $excludes as $key => $value ) {
$exclude[] = $value->cat_ID;
}
}
// remove child cats
if ( isset($exclude) && is_array($exclude) ) {
$cats .= " AND " . $wpdb->prefix . "term_relationships.term_taxonomy_id NOT IN (" . implode(",", $exclude) . ") ";
}
}
return $cats;
}
if ( !is_admin() ) {
add_filter( 'posts_where', 'fb_filter_child_cats' );
}
}
and also Update 3 for a better solution without an sql-select:
function fb_filter_child_cats($query) {
$cat = get_term_by('name', $query->query_vars['category_name'], 'category');
$child_cats = (array) get_term_children( &$cat->term_id, 'category' );
// also possible
// $child_cats = (array) get_term_children( get_cat_id($query->query_vars['category_name']), 'category' );
if ( !$query->is_admin )
$query->set( 'category__not_in', array_merge($child_cats) );
return $query;
}
add_filter( 'pre_get_posts', 'fb_filter_child_cats' );
Frank,
it seems that you changed the excluded categories’ array name midway. I’d suggest to amend line #18 to read:
$cats .= " AND " . $wpdb->prefix . "term_taxonomy.term_id NOT IN (" . implode(",", $exclude) . ") ";NB:
implode(",", $exclude)replacesimplode(",", $exs)@Robert: thanks for your hint, i have fix the bug
First of all, thanks for this function!
I’ve added the script in my ../themes/my_theme/functions.php and this is the error:
Catchable fatal error: Object of class stdClass could not be converted to string in line:
$cats .=” AND “.$wpdb->prefix .”term_taxonomy.term_id NOT IN (“.implode(“,”, $excludes).”)”;
What could it be?
Cristian:
Should be
$cats .=" AND ".$wpdb->prefix ."term_taxonomy.term_id NOT IN (".implode(",", $exclude).")";Is there a way to do this on the homepage?
Hi,
I need a little help regarding tweaking the display of Categories on Navigation Bar..
I have a parent Category (let’s suppose A)
then sub categories under this Parent Category let’s suppose A1, A2, A3, A4, A5, A6..
Now I want to add sub categories under these Child Categories, I mean, now I want to add some sub categories under A1, A2, A3, A4 but I dont want to show them in navigation bar..
2nd, I want if someone clicks at A,,,,it shouls not display all posts under A but it should just diplay its sub categories & same if someone clicks on A1 or A2, it should not display Posts of A1 or A2 rather it should diplay sub categories of A1 ,, A2 & so on..
is it possible ??
Thanks
That’s an interesting solution, but it’s actually much easier than this.
See http://tomcat23.wordpress.com/2010/07/26/query_posts-and-how-to-use-it-in-your-functions-php-template-file/
Is there a way to exclude not all subcategories, just 2 out of 5?
Thank you,
Wolf
It seems that this is not working with WP 3.1
(do you think it can be related to changing deprecated “caller_get_posts” with “ignore_sticky_posts”?).
Can you please fix or update the code?
With the new version 3.1 of WordPress, it gives the next error:
WordPress database error: [Unknown column ‘wp_term_taxonomy.term_id’ in ‘where clause’]
SELECT SQL_CALC_FOUND_ROWS wp_posts.* FROM wp_posts INNER JOIN wp_term_relationships ON (wp_posts.ID = wp_term_relationships.object_id) WHERE 1=1 AND ( wp_term_relationships.term_taxonomy_id IN (21,45,49) ) AND wp_posts.post_type = ‘post’ AND (wp_posts.post_status = ‘publish’) AND wp_term_taxonomy.term_id NOT IN (42,46) GROUP BY wp_posts.ID ORDER BY wp_posts.post_date DESC LIMIT 0, 3
in the front page (don’t display the posts of the featured categories), and don’t list any post in the categories-list pages.
Thanks
Yes, this code doesnt work with 3.1. WordPress didnt find any articles in the category.
Wolf
I agree. This doesnt seem to work with WP 3.1. Hm… Any ideas how to fix it?
Now, i have update for WP 3.1
Thank you, Frank, but I can not see any change in the code update for WP 3.1 …
@Martin: sorry, i have an error with my copy/paste workflow 🙁
Now i have change the code and hope, this works
Thank you for your interest and your attention, but I agree with Martin, the updated code is the same as the previous one.
Maybe a little lapse…
Sorry for my bad english in this and my previous reply (I’m writing from Spain).
I really appreciate all the advices of your site.
Sorry, I had not refreshed this page in my browser…
I see now the changes.
Seems very interesting, I will check and try it.
Once again many thanks, thanks also for your site, and sorry for my poor english.
Thanks for fixing it, Frank! 😉