Custom Query Filter for Elementor Posts by relationship field (ACF) - wordpress

Question

I have a custom post type setup called 'Artists'. Each Single Artist is a page (artist profile if you wish), has a list of products that are associated with that artist via the relationship field type through Advanced Custom Fields (ACF). I need the products to be displayed within their categories on the artist page. So within Elementor I need to specify a 'Query Filter ID' to simply split the products into categories.
What I have tried so far
I am trying to display only products from a certain category in a list via a custom query as I need to generate a Query ID.
I've been trying a bunch of different ways to do this but now I'm at a loss. The latest code I have is here... what am I missing?
/** Product category 'SOFTWARE' **/
add_filter( 'software_product', 'product_category_software' );
function product_category_software( $variable ) {
$query_args = array(
'post_type' => 'product',
'tax_query' => array(
array(
'taxonomy' => 'category',
'field' => 'slug',
'terms' => 'software',
),
),
);
return $variable;
}

Answer 1

Answer
You need to use this
https://developers.elementor.com/custom-query-filter/#Using_the_Custom_Filter
arbitrary_name_query_id - the QUERY ID that you fill in the Elementor field,
the code to be placed within functions.php:
add_action( 'elementor/query/arbitrary_name_query_id', function( $query ) {
$meta_query = $query->get( 'meta_query' );
$meta_query[] = [
'key' => 'acf_key', // put ACF relationship field name
'value' => get_the_ID(),
'compare' => '=',
];
$query->set( 'meta_query', $meta_query );
} );
Regarding to the given code
First of all, as Wordpress Documentation on filters says:
They (i.e. filters) provide a way for functions to modify data of other
functions.
Which means that the filter function, in this case it's product_category_software, receives data that subsequntly modifies and returns it back:
add_filter( 'software_product', 'product_category_software' );
function product_category_software( $variable ) { // receive $variable
/**
* Modify $variable here
*/
return $variable; // return modified $variable
}
In your case product_category_software doesn't modify what receives, but introduces new peace of data $query_args which makes no sence, since it is not going to be returned.
Secondly, the first argument of the add_filter function should be an existent filter name, the software_product is not.
Thirdly, the correct name of the taxonomy of product categories is product_cat.
Getting products from a certain category
Aproach #1 Modfying main query with pre_get_posts
function your_arbitrary_name( $query ) { // receive
if ( ! is_admin() && is_post_type_archive( 'product' ) && $query->is_main_query() ) {
$tax_query = array(
array(
'taxonomy' => 'product_cat',
'field' => 'slug',
'terms' => array('software'),
)
);
$query->set( 'meta_query', $tax_query ); // modify
}
return $query; // and return
}
add_action( 'pre_get_posts', 'your_arbitrary_name', 20 );
Aproach #2 Use wc_get_products or WC_Product_Query
Example, use in your Controller or even in the template:
$args = array(
'category' => array( 'software' ),
);
$products = wc_get_products( $args );
Read the Docs about wc_get_products and WC_Product_Query