我已经四处寻找了一下，但什么都没有找到（也许我搜索得不够好？）但我试图在从另一个分类法加载的分类法上设置父分类法。

例如，我有汽车品牌和汽车模型，当添加一个新模型时，我想选择它的父级（汽车品牌），而不是它本身的另一个父级。

make不能有任何父级，但可以有无限的子级，模型不能有任何子级，并且父级必须有make。

这可能吗？最好没有插件。

/* Makes */
$labels = array(
\'name\' => _x( \'Makes\', \'taxonomy general name\' ),
    \'singular_name\' => _x( \'Make\', \'taxonomy singular name\' ),
    \'search_items\' =>  __( \'Search Makes\' ),
    \'all_items\' => __( \'All Makes\' ),
    \'parent_item\' => __( \'Parent Make\' ),
    \'parent_item_colon\' => __( \'Parent Make:\' ),
    \'edit_item\' => __( \'Edit Make\' ),
    \'update_item\' => __( \'Update Make\' ),
    \'add_new_item\' => __( \'Add New Make\' ),
    \'new_item_name\' => __( \'New Make\' ),
);  
register_taxonomy(\'makes\', \'car\', array(\'hierarchical\' => false, \'labels\' => $labels, \'query_var\' => false, \'rewrite\' => false, \'with_front\' => false));

/* Models */
$labels = array(
\'name\' => _x( \'Models\', \'taxonomy general name\' ),
    \'singular_name\' => _x( \'Model\', \'taxonomy singular name\' ),
    \'search_items\' =>  __( \'Search Models\' ),
    \'all_items\' => __( \'All Models\' ),
    \'parent_item\' => __( \'Parent Model\' ),
    \'parent_item_colon\' => __( \'Parent Model:\' ),
    \'edit_item\' => __( \'Edit Model\' ),
    \'update_item\' => __( \'Update Model\' ),
    \'add_new_item\' => __( \'Add New Model\' ),
    \'new_item_name\' => __( \'New Model\' )
);
register_taxonomy(\'models\', \'car\', array(\'hierarchical\' => true, \'labels\' => $labels, \'query_var\' => false, \'rewrite\' => false, \'with_front\' => false));

这个问题有点关联：Show WordPress Custom Taxonomy Items Based On a Selected Item From Another Custom Taxonomy 然而，我假设父/子元素来自一个分类法？在我的例子中，它们需要是两个独立的分类法。

<?php
add_filter( \'taxonomy_parent_dropdown_args\', \'alter_parent_taxonomy\', 10, 2 );

function alter_parent_taxonomy( $args, $taxonomy ) {

    if ( \'models\' != $taxonomy ) return $args; // no change

    $args[\'taxonomy\'] = \'makes\';
    $args[\'depth\'] = 1;

    return $args;
}
?>