Allow terms to match the order in the include parameter

[glebkema]

Fix #66

To fix the problem it's necessary to change the behavior of the plugin in two aspects.

1) scporder_get_terms_orderby()

This method is used with the filter get_terms_orderby and changes the $orderby on t.term_order.

$orderby = 't.term_order';
return $orderby;

To fix this, it's enough to add one more check:

if (isset($args['include']) && isset($args['orderby']) && 'include' === $args['orderby'])
	return $orderby;

2) scporder_get_object_terms()

This method is used with two filters get_terms and wp_get_object_terms and sorts the found terms by the term_order.

usort($terms, array($this, 'taxcmp'));
return $terms;

This situation is more complicated. To check the include option in an array of arguments, we need to pass the $args parameter to the function.

if (isset($args['include']) && isset($args['orderby']) && 'include' === $args['orderby'])
	return $terms;

But this parameter is located at different positions in the mentioned hooks:

apply_filters( 'get_terms', $terms, $taxonomies, $args, $term_query );
apply_filters( 'wp_get_object_terms', $terms, $object_ids, $taxonomies, $args );

In this regard, I propose to add an auxiliary method. Its role is to invoke a neighboring method with another set of arguments:

public function scporder_get_object_terms($terms, $object_ids, $taxonomies, $args) {
    return $this->scporder_get_terms($terms, $taxonomies, $args);
}

public function scporder_get_terms($terms, $taxonomies, $args) {

And use a specific function for each hook:

add_filter('wp_get_object_terms', array($this, 'scporder_get_object_terms'), 10, 4);
add_filter('get_terms', array($this, 'scporder_get_terms'), 10, 3);

[puikinsh]

Thank you @glebkema — this was a thorough, well-reasoned write-up, and you were spot on. 🙏

orderby=include was indeed being overridden by the custom term order, and the root cause was exactly as you described: the object-terms callback didn't receive $args, and get_terms / wp_get_object_terms pass it at different argument positions.

Fixed in 2.7.1 (just released). The term filters now receive $args, and both scporder_get_terms_orderby() and the shared terms sorter bail out when orderby === 'include' — implemented along the lines you proposed (a thin per-hook callback that hands $args to the sorter). Verified end-to-end: an include => [4,7,5], orderby => 'include' query now returns 4,7,5 instead of being re-sorted.

You're credited in the changelog. Closing as resolved — much appreciated!