Ticket #29839: 20141112_01.diff

taxonomy.php

@@ -1640 +1640 @@
 
         $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' => '', 'children_only' => '',
                 'hierarchical' => true, 'child_of' => 0, 'get' => '', 'name__like' => '', 'description__like' => '',
                 'pad_counts' => false, 'offset' => '', 'search' => '', 'cache_domain' => 'core' );
         $args = wp_parse_args( $args, $defaults );
@@ -1653 +1653 @@
                 $args['pad_counts'] = false;
         }
 
-        // 'parent' overrides 'child_of'.
-        if ( 0 < intval( $args['parent'] ) ) {
+        // 'parent' and 'children_only' override 'child_of'
+        if ( 0 < intval( $args['parent'] ) || true === $args['children_only'] ) {
                 $args['child_of'] = false;
         }
 
         if ( 'all' == $args['get'] ) {
+                $args['children_only'] = 0;
                 $args['child_of'] = 0;
                 $args['hide_empty'] = 0;
                 $args['hierarchical'] = false;
@@ -1691 +1692 @@
                 }
         }
 
+        // Check for heirarchical taxonomy
+        $children_only = $args['children_only']; // boolean
+        if ( $children_only ) {
+                // Empty if taxonomy is not heirarchical; term ids if it is.
+                // Note that we are not checking for a specific child or parent, just the
+                //  existence of an heirarchical taxonomy
+                $hierarchy = _get_term_hierarchy( reset( $taxonomies ) );
+                if ( empty( $hierarchy )) {
+                        return $empty_array;
+                }
+        }
+
         // $args can be whatever, only use the args defined in defaults to compute the key
         $filter_key = ( has_filter('list_terms_exclusions') ) ? serialize($GLOBALS['wp_filter']['list_terms_exclusions']) : '';
         $key = md5( serialize( wp_array_slice_assoc( $args, array_keys( $defaults ) ) ) . serialize( $taxonomies ) . $filter_key );
@@ -1790 +1803 @@
         }
 
         if ( ! empty( $exclude ) ) {
-                $exterms = wp_parse_id_list( $exclude );
+                $exterms = $excluded_terms( $exclude );
                 if ( empty( $exclusions ) ) {
                         $exclusions = implode( ',', $exterms );
                 } else {
@@ -1798 +1811 @@
                 }
         }
 
+        if ( $children_only ) {
+                $terms_to_exclude = "";
+                $term_heirarchy = _get_term_hierarchy( reset( $taxonomies ) );
+                if ( ! empty( $term_heirarchy ) ) {
+                        // Any term listed in $term_heirarchy has by definition a child term, so exclude it
+                        foreach ( array_keys($term_heirarchy) as $excluded_index=>$excluded_id ) {
+                                if ( empty($terms_to_exclude) ) {
+                                        $terms_to_exclude = $excluded_id;
+                                } else {
+                                        $terms_to_exclude .= ', ' . $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 . ')';
         }
@@ -1852 +1885 @@
         $offset = $args['offset'];
 
         // don't limit the query results when we have to descend the family tree
-        if ( $number && ! $hierarchical && ! $child_of && '' === $parent ) {
+        if ( $number && ! $hierarchical && ! $child_of && '' === $parent && '' === $children_only) {
                 if ( $offset ) {
                         $limits = 'LIMIT ' . $offset . ',' . $number;
                 } else {