Ticket #29839: 20141116_01-taxonomy.2.diff

src/wp-includes/taxonomy.php

@@ -1616 +1616 @@
  *     @type int          $child_of          Term ID to retrieve child terms of. If multiple taxonomies
  *                                           are passed, $child_of is ignored. Default 0.
  *     @type int|string   $parent            Parent term ID to retrieve direct-child terms of. Default empty.
+ *     @type bool         $childless         Returns terms that have no children. Null if taxonomy is not
+ *                                           hierarchical. Default false
  *     @type string       $cache_domain      Unique cache key to be produced when this query is stored in an
  *                                           object cache. Default is 'core'.
  * }
@@ -1640 +1642 @@
 
         $defaults = array('orderby' => 'name', 'order' => 'ASC',
                 'hide_empty' => true, 'exclude' => array(), 'exclude_tree' => array(), 'include' => array(),
-                'number' => '', 'fields' => 'all', 'slug' => '', 'parent' => '',
+                'number' => '', 'fields' => 'all', 'slug' => '', 'parent' => '', 'childless' => false,
                 'hierarchical' => true, 'child_of' => 0, 'get' => '', 'name__like' => '', 'description__like' => '',
                 'pad_counts' => false, 'offset' => '', 'search' => '', 'cache_domain' => 'core' );
         $args = wp_parse_args( $args, $defaults );
@@ -1659 +1661 @@
         }
 
         if ( 'all' == $args['get'] ) {
+                $args['childless'] = false;
                 $args['child_of'] = 0;
                 $args['hide_empty'] = 0;
                 $args['hierarchical'] = false;
@@ -1798 +1801 @@
                 }
         }
 
+        $childless = (bool) $args['childless']; // boolean
+        if ( $childless ) {
+                $terms_to_exclude = "";
+                $term_hierarchy = _get_term_hierarchy( reset( $taxonomies ) );
+
+                // If $term_hierarchy is empty, then there are no exclusions because either the
+                //  $taxonomy is flat, or it's hierarchical but has no child terms. In both cases,
+                //  return everything
+                if ( ! empty( $term_hierarchy ) ) {
+                        // Any term listed in $term_hierarchy has by definition a child term, so exclude it
+                        foreach ( array_keys($term_hierarchy) as $excluded_index=>$excluded_id ) {
+                                if ( empty($terms_to_exclude) ) {
+                                        $terms_to_exclude = intval( $excluded_id );
+                                } else {
+                                        $terms_to_exclude .= ', ' . intval( $excluded_id );
+                                }
+                        }
+                        if ( empty( $exclusions ) ) {
+                                $exclusions = $terms_to_exclude;
+                        } else {
+                                $exclusions .= ', ' . $terms_to_exclude;
+                        }
+                }
+        }
+
         if ( ! empty( $exclusions ) ) {
                 $exclusions = ' AND t.term_id NOT IN (' . $exclusions . ')';
         }