Wordpress WP_Term_Query自定义分类选择选项

Question

The below code works really well for pulling in a select option list for all the entries in a custom taxonomy called 'make'. It only pulls in parent level ones which is perfect.

            <select id="make" name="make">
                <option value="">--</option>
                <?php $term_query = new WP_Term_Query( array( 'taxonomy' => 'make', 'parent' => 0 ) ); if ( ! empty( $term_query->terms ) ) {
                    foreach ( $term_query ->terms as $term ) {
                        echo '<option class="' . $term->name . '" value="' . $term->name . '">' . $term->name . '</option>';
                    }
                } else {    
                };?>
            </select>

However, i would like to create another identical version of this code but instead of pulling in a list of all the parent values, it should pull in all the child values. Not for a particular page or post, but should output a select list of ALL the child entries of a custom taxonomy, ignoring the parents. Any help is massively appreciated!

Answer 1

you could use get_term_children and get_term_by functions to build your second select:

<select id="make" name="make">
<option value="">--</option>
<?php
     $term_query = new WP_Term_Query( array( 'taxonomy' => 'make', 'parent' => 0 ) );
     if ( ! empty( $term_query->terms ) ) {
        foreach ( $term_query ->terms as $term ) {
            $term_children = get_term_children( $term->term_id, 'make' );
            foreach($term_children as $children){
                $child = get_term_by( 'id', $children, 'make' );
                echo '<option class="' . $child->name . '" value="' . $child->name . '">' . $child->name . '</option>';
            }
        }
     } else {
     };
?>
</select>