How to get woocommerce attributes used for product variations? - wordpress

Question

I'm trying to get a list with all woocommerce attributes and values, but only those used for product variations (for example, I want to get "size" and "color" values, but not other attributes used only for information purposes like "fabric" or "weight").
I'm using this code:
$allAttributes = wc_get_attribute_taxonomies();
foreach ($allAttributes as $att) {
$wcAttribute = wc_get_attribute($att->attribute_id);
[...]
}
At this point, I want to check if this $wcAttribute is used for any product variation, to add it to my list or not, but I don't know how to proceed.
Any help?

Answer 1

I respond to myself, because I found a solution. Probably, it isn't the best solution, but it works (if someone has any better solution, I'll appreciate):
function getAllWCAttributes()
{
/* Format for attributes: ['attribute_id' => ['id', 'name', 'values'=>['id', 'name'] ] ]*/
$attributes = array();
$allAttributes = wc_get_attribute_taxonomies();
foreach ($allAttributes as $att) {
if (isAttributeUsedForVariations($att)) {
$wcAttTerms = get_terms('pa_' . $att->attribute_name);
$terms = array();
foreach ($wcAttTerms as $wcTerm) {
$terms[] = array(
'id' => $wcTerm->term_id,
'name' => $wcTerm->name
);
}
$attributes[$att->attribute_id] = array(
'id' => $att->attribute_id,
'name' => $att->attribute_label,
'values' => $terms
);
}
}
return $attributes;
}
function isAttributeUsedForVariations($attribute)
{
$terms = array();
$attTerms = get_terms('pa_' . $attribute->attribute_name);
foreach ($attTerms as $attTerm) {
$terms[] = $attTerm->slug;
}
$args = array(
'post_type' => 'product_variation',
'post_status' => 'publish',
'meta_query' => array(
array(
'key' => 'attribute_pa_' . $attribute->attribute_name,
'value' => $terms,
'compare' => 'IN'
)
)
);
$variationsQuery = new WP_Query($args);
return ($variationsQuery->post_count > 0)? true: false;
}
Documentation:
wc_get_attribute_taxonomies()
get_terms()
WP_Query