wp-admin filter cpt by taxonomy 和 taxonomy 关系

wp-admin filter cpt by taxonomy and taxonomy relationship

我有类别和消息自定义 post 类型,它们都可以有一个名为子类别的自定义分类。

我希望能够通过自定义分类法过滤 wp-admin 上的消息,例如显示 Subcategory_1 中的所有消息。我设法用我找到的代码做到了 here.

问题是我还想按与消息具有相同子类别的类别过滤它们。

示例:

预期结果是,当用户从过滤器下拉列表中选择 Category_1 时,只有 Message_1Message_2 显示。

当前代码(只能按子类别筛选):

function todo_restrict_manage_posts() {
 global $typenow;
 $args=array( 'public' => true, '_builtin' => false ); 
 $post_types = get_post_types($args);
 if ( in_array($typenow, $post_types) ) {
 $filters = get_object_taxonomies($typenow);
    foreach ($filters as $tax_slug) {
        $tax_obj = get_taxonomy($tax_slug);
        wp_dropdown_categories(array(
            'show_option_all' => __('Show All '.$tax_obj->label ),
            'taxonomy' => $tax_slug,
            'name' => $tax_obj->name,
            'orderby' => 'term_order',
            'selected' => $_GET[$tax_obj->query_var],
            'hierarchical' => $tax_obj->hierarchical,
            'show_count' => true,
            'hide_empty' => false
        ));
    }
 }
}
function todo_convert_restrict($query) {
 global $pagenow;
 global $typenow;
 if ($pagenow=='edit.php') {
    $filters = get_object_taxonomies($typenow);
    foreach ($filters as $tax_slug) {
        $var = &$query->query_vars[$tax_slug];
        if ( isset($var) ) {
            $term = get_term_by('id',$var,$tax_slug);
            $var = $term->slug;
        }
    }
 }
 return $query;
}
 add_action( 'restrict_manage_posts', 'todo_restrict_manage_posts' );
 add_filter('parse_query','todo_convert_restrict');

当前过滤器(缺少按类别过滤)

问题出在这一行:

$var = &$query->query_vars[$tax_slug];

顺便说一句,& 符号不是必需的,$var 现在是术语的别名而不是 ID

所以这一行:

$term = get_term_by('id',$var,$tax_slug);

需要:

$term = get_term_by('slug',$var,$tax_slug);

如果有效请告诉我。

如果我理解正确的话,假设类别 post 类型 slug 是 categories 并且子类别 taxonomy slug 是 subcategories,以下应该适合你:

SNIPPET 1:这将添加 "filter by Category" 下拉菜单:

add_action( 'restrict_manage_posts', 'add_categories_cpt_filter' );
function add_categories_cpt_filter( $post_type ) {
    // Display the filter only on the Messages edit page.
    if ( 'messages' === $post_type ) {
        $posts = get_posts( [
            'post_type'      => 'categories',
            'posts_per_page' => 99999,
            'orderby'        => 'title',
            'order'          => 'ASC',
        ] );

        echo '<select name="categories_cpt" class="postform">';

        if ( ! empty( $posts ) ) {
            echo '<option value="0">Show All Categories</option>';
        } else {
            echo '<option value="0">No Categories</option>';
        }

        $selected = isset( $_GET['categories_cpt'] ) ?
            absint( $_GET['categories_cpt'] ) : 0;
        foreach ( $posts as $p ) {
            printf( '<option value="%s"%s>%s</option>',
                $p->ID, selected( $selected, $p->ID, false ),
                esc_html( $p->post_title ) );
        }

        echo '</select>';
    }
}

SNIPPET 2:这将按所选类别的条款过滤消息:

add_action( 'pre_get_posts', 'filter_messages_by_categories_cpt' );
function filter_messages_by_categories_cpt( $query ) {
    // Enable the filter only on the Messages edit page.
    if ( $query->is_admin && $query->is_main_query() &&
        ( $screen = get_current_screen() ) &&
        ( 'edit-messages' === $screen->id ) &&
        ! empty( $_GET['categories_cpt'] )
    ) {
        $tax_query = $query->get( 'tax_query' );
        $tax_query = is_array( $tax_query ) ? $tax_query : [];

        $term_ids = get_terms( [
            'taxonomy'   => 'subcategories',
            'object_ids' => absint( $_GET['categories_cpt'] ),
            'fields'     => 'ids',
        ] );
        if ( ! is_wp_error( $term_ids ) && ! empty( $term_ids ) ) {
            $tax_query[] = [
                'taxonomy' => 'subcategories',
                'terms'    => $term_ids,
            ];

            $query->set( 'tax_query', $tax_query );
        }
    }
}

您可以在有问题的代码之后添加上面的两个片段,即在 add_filter('parse_query','todo_convert_restrict');.

之后