Reverse Query ACF Term "meta"

• JoelStransky

• July 28, 2016 at 12:47 pm

Lots of threads lately asking for ACF to support term meta officially. This might actually be a use case.

I’m trying to display a grouped <select> field where the group names are that of one Taxonomies terms, and each groups members are terms in a separate taxonomy associated with the other one via an ACF select field.

I’ll elaborate.
I’ve registered Taxonomy_A who’s terms are locations. I also have Taxonomy_B who’s terms are units. Each unit exists within a location so all Taxonomy_B terms have a required ACF field for choosing its parent location. This is all fine, but now I’m trying to populate a <select> where each <optgroup> is a location and its<options> are units.

How would I get all terms of Taxonomy_B where its ACF field data equals a certain value (in this case, a location)?

• James

• July 28, 2016 at 1:53 pm

Hi @joelstransky

ACF save the taxonomies’ value in the wp_options table. In this case, you need to use the wpdb class.

Here’s an example how to do it:

// you can set the ID automatically. This is just an example
$location_id = 99;

// this is the taxonomy b's slug
$taxonomy_slug = 'taxonomy_b';

// this is the taxonomy b's parent field name
$taxonomy_field_name = 'location_field_name';

$rows = $wpdb->get_results($wpdb->prepare( 
    "
    SELECT option_name 
    FROM {$wpdb->prefix}options
    WHERE option_name LIKE %s
    AND option_value = %s
    ",
    $taxonomy_slug . '_%_' . $taxonomy_field_name,
    $location_id
));

$unit_ids = array();

foreach( $rows as $row ){
    preg_match('/^' . $taxonomy_slug . '_(\d*)_' . $taxonomy_field_name . '$/', $row->option_name, $matches);
    $unit_ids[] = $matches[1];
}

$terms = get_terms(array(
    'taxonomy' => $taxonomy_slug,
    'hide_empty' => false,
    'include' => $unit_ids,
));

print_r($terms);

I hope this helps 🙂

• JoelStransky

• July 28, 2016 at 5:38 pm

Thanks @James,
It wasn’t until my drive home that I realized the lack of a wp_options api meant I was probably going to have to resort to wpdb. I’ll check it out tomorrow but this looks like exactly what I was after. Cheers.
Sadly, this would be easier if termsmeta was adopted.

• JoelStransky

• July 29, 2016 at 7:11 am

So I modified your solution with the intent making the value optional. I’m not very good with SQL so I doubt my use of the AND statement is the cleanest way to do that.

function acf_get_terms( $args = array() ) {
  global $wpdb;
  $defaults = array(
    'taxonomy_slug'     => '',
    'acf_field_name'    => null,
    'meta_value'        => '',
  );
  $args = wp_parse_args( $args, $defaults );

  if ( empty($args['taxonomy_slug']) || ! taxonomy_exists( $args['taxonomy_slug'] ) || empty( $args['acf_field_name'] ) ) {
    return new WP_Error( 'invalid_option_name', __('ACF term meta names are formatted as {$term->taxonomy}_{$term->term_id}_{$field[\'name\']}.') );
  }

  $rows = $wpdb->get_results($wpdb->prepare(
      "
      SELECT option_name
      FROM {$wpdb->prefix}options
      WHERE option_name LIKE %s
      AND option_value LIKE %s
      ",
      $args['taxonomy_slug'] . '_%_' . $args['acf_field_name'],
      empty($args['meta_value']) ? '%' : $args['meta_value']
  ));

  $unit_ids = array();

  foreach( $rows as $row ){
      preg_match('/^' . $args['taxonomy_slug'] . '_(\d*)_' . $args['acf_field_name'] . '$/', $row->option_name, $matches);
      $unit_ids[] = $matches[1];
  }

  $terms = get_terms(array(
      'taxonomy' => $args['taxonomy_slug'],
      'hide_empty' => false,
      'include' => $unit_ids,
  ));

  return $terms;
}