Create a plugin with new shortcodes derived from WooCommerce - wordpress

Question

WooCommerce comes with standard shortcode [product_category].
I wanted to get a shortcode with the same behavior, but filtering per vendor (a custom taxonomy) instead of per category.
So I have replicated and modified the code of [product_category], directly in woocommerce file class-wc-shortcodes.php to create [product_vendor].
This way, it is working fine. But I know it is not proper because my shortcodes will be erased at each upgrade.
So I tried to create my own plugin to host the code of [product_vendor].
But simply moving the code into it, is not working (my website gets down). I also tried to declare global $woocommerce at the begining. Not working either. I guess it is because the code is refering to elements of class WC_Shortcodes and woocommerce functions... but I am not at ease with class so I don't know how to solve the issue...!
Here is the code I wrote in class-wc-shortcodes.php. Could you tell me what are the changes I should do so that this code is working in my own plugin ?
Many thanks
class WC_Shortcodes {
/**
* Init shortcodes.
*/
public static function init() {
$shortcodes = array(
'product' => __CLASS__ . '::product',
'product_page' => __CLASS__ . '::product_page',
'product_category' => __CLASS__ . '::product_category',
'product_vendor' => __CLASS__ . '::product_vendor', //new shortcode
...
}
(...)
/**
* Shortcode : List of products per vendor.
*/
public static function product_vendor( $atts ) {
$atts = shortcode_atts( array(
'per_page' => '12',
'columns' => '4',
'orderby' => 'category',
'order' => 'asc',
'vendor' => '', // Slugs
'operator' => 'IN'
), $atts, 'product_vendor' );
if ( ! $atts['vendor'] ) {
return '';
}
// Default ordering args
$ordering_args = WC()->query->get_catalog_ordering_args( $atts['orderby'], $atts['order'] );
$meta_query = WC()->query->get_meta_query();
$query_args = array(
'post_type' => 'product',
'post_status' => 'publish',
'ignore_sticky_posts' => 1,
'orderby' => $ordering_args['orderby'],
'order' => $ordering_args['order'],
'posts_per_page' => $atts['per_page'],
'meta_query' => $meta_query
);
$query_args = self::_maybe_add_vendor_args( $query_args, $atts['vendor'], $atts['operator'] );
if ( isset( $ordering_args['meta_key'] ) ) {
$query_args['meta_key'] = $ordering_args['meta_key'];
}
$return = self::product_loop( $query_args, $atts, 'product_cat' );
// Remove ordering query arguments
WC()->query->remove_ordering_args();
return $return;
}
(...)
private static function _maybe_add_vendor_args( $args, $vendor, $operator ) {
if ( ! empty( $vendor ) ) {
$args['tax_query'] = array(
array(
'taxonomy' => 'yith_shop_vendor',
'terms' => array_map( 'sanitize_title', explode( ',', $vendor ) ),
'field' => 'slug',
'operator' => $operator
)
);
}
return $args;
}
In my own plugin, I have "copy paste" the code, with minor changes. But if I activate this plugin, my site can't be launched at all. I also tried to include my function in "class WC_Shortcodes", or to add/remove the declaration of global variable $woocommerce... Here is what I wrote in my plugin :
function test_shortcode_in_my_plugin ($atts){
global $woocommerce;
$atts = shortcode_atts( array(
'per_page' => '12',
'columns' => '4',
'orderby' => 'category',
'order' => 'asc',
'vendor' => '', // Slugs
'operator' => 'IN' // Possible values are 'IN', 'NOT IN', 'AND'.
), $atts, 'product_vendor' );
if ( ! $atts['vendor'] ) {
return ''; //si aucune catégorie n'est spécifiée, ne rien retourner
}
// Default ordering args
$ordering_args = WC()->query->get_catalog_ordering_args( $atts['orderby'], $atts['order'] );
$meta_query = WC()->query->get_meta_query();
$query_args = array( // construction du tableau de résultats
'post_type' => 'product',
'post_status' => 'publish',
'ignore_sticky_posts' => 1,
'orderby' => $ordering_args['orderby'],
'order' => $ordering_args['order'],
'posts_per_page' => $atts['per_page'],
'meta_query' => $meta_query
);
$query_args = self::_maybe_add_vendor_args( $query_args, $atts['vendor'], $atts['operator'] );
// Fonction qui ajoute la condition sur le "vendor" dans la requete
if ( isset( $ordering_args['meta_key'] ) ) {
$query_args['meta_key'] = $ordering_args['meta_key'];
}
$return = self::product_loop( $query_args, $atts, 'product_cat' );
// Remove ordering query arguments
WC()->query->remove_ordering_args();
return $return;
}
add_shortcode( 'test_shortcode', 'test_shortcode_in_my_plugin' );