我想根据帖子类别做一个过滤器。我试图在数据类别属性中添加类别名称，但似乎不起作用。这就是我所尝试的：

<article id="post-<?php the_ID(); ?>" <?php post_class(); ?> data-category="<?php $category_detail=get_the_category(); foreach($category_detail as $cd){ $cd->cat_name;}?>">
    <header class="entry-header">
        <?php
        if ( is_singular() ) {
            the_title( \'<h1 class="entry-title">\', \'</h1>\' );
        }
        else {
            the_title( \'<h2 class="entry-title"><a href="\' . esc_url( get_permalink() ) . \'" rel="bookmark">\', \'</a></h2>\' );
        }

        if ( \'post\' === get_post_type() ) {
            ?>
            <div class="entry-meta">
                <?php dfib_theme_entry_meta(); ?>
            </div>
        <?php } ?>
    </header>
    <?php dfib_theme_post_thumbnail(); ?>
        <div class="entry-content">             
            <?php 
                the_excerpt();

            wp_link_pages( array(
                \'before\' => \'<div class="page-links">\' . esc_html__( \'Pages:\', \'dfib-theme\' ),
                \'after\'  => \'</div>\',
            ) );
            ?>
        </div>
    <footer class="entry-footer">
        <a href="<?php the_permalink(); ?>" class="btn">Meer info</a>
    </footer>
</article>