Woocommerce – Hide out of stock items that appears using “Layered nav: filter”

I come across a pretty annoying bug-feature in woocommerce. If someone uses Layered navigation filters and has variable products based on a specific attribute, the filtering will return all the products with the specific attribute, even if this variation is out of stock.  If someone  is selling clothes-shoes for example this is quite disturbing.

This bug is reported to Woocommerce github issue tracker here. It is rated as a won’t fix mainly because the attributes of a variable product is not directly connected with the Taxonomy Terms.

Building upon a solution from http://www.stimart.net/web/woocommerce-hide-out-of-stock-items-that-appears-using-layered-nav-filter-widget/ which is removing the products before showing in the template pages , I went deeper in the woocommerce core. This was mainly because the aforementioned solution had trouble with more advanced themes and especially with the pagination. In simple themes it worked almost perfectly.

So this is my solution.

Open file in woocommerce plugin -> includes -> class-wc-query.php

Find Function

[php]

public function layered_nav_query( $filtered_posts ) {

[/php]

After

[php]

global $_chosen_attributes;

[/php]

Add

[php]     global $wpdb;[/php]

And after

[php]
$posts = get_posts(
array(
‘post_type’     = > ‘product’,
‘numberposts’     = > -1,
‘post_status’     = > ‘publish’,
‘fields’         => ‘ids’,
‘no_found_rows’ => true,
‘tax_query’ => array(
array(
‘taxonomy’     => $attribute,
‘terms’     => $value,
‘field’     => ‘term_id’
)
)
)
);[/php]

Add

[php]

//continue fix
if ($attribute ==”pa_size”)    {
$new_ids= array();
$queryslug =”SELECT *  FROM {$wpdb->prefix}term_taxonomy as taxonomy, {$wpdb->prefix}terms as term  where taxonomy.term_id= $value and taxonomy.term_id = term.term_id ” ;
$slugr = $wpdb->get_results( $queryslug );
$slug = $slugr[0]->slug;
foreach ($posts as $post_id)
{
$query =”SELECT *  FROM {$wpdb->prefix}posts as posts , {$wpdb->prefix}postmeta as postmeta where posts.post_parent= $post_id  AND posts.ID = postmeta.post_id AND meta_key like ‘attribute_$attribute’  AND meta_value like ‘$slug’ ” ;
$variation_ids = $wpdb->get_results( $query );
foreach ($variation_ids as $variation_id){
$var_id = $variation_id->ID;
$query2 =”SELECT post_id  FROM {$wpdb->prefix}postmeta as postsmeta  where post_id= $var_id and meta_key like ‘_stock_status’ and meta_value like ‘instock’ ” ;
$result = $wpdb->get_results( $query2 );
if($result){
$new_ids[]=$post_id;
}
}
}
$posts=$new_ids;
}
//END fix

[/php]

Where pa_size can be renamed to your attribute.