在这里使用AJAX并尝试基于用户交互显示帖子。现在，我有它的工作，用户作出类别下拉选择和职位加载相应。我想做的是更进一步，在另一个下拉列表中填充基于所选父类别的子类别。查看网站here.

jQuery

$(\'#ajaxFilter select\').on(\'change\', function(event) {
if(event.preventDefault) { event.preventDefault(); }
$this = $(this);
$value = this.value;
$page = $this.data(\'page\');
$term = $this.data(\'term\');
$qty = $this.closest(\'#ajaxFilter\').data(\'paged\')

    $params = {
        //Bind parameters
        \'value\': $value,
        \'page\' : $page,
        \'term\' : $term,
        \'qty\'  : $qty,
    };

    //Run the query with those parameters
    get_posts($params);
});



function get_posts($params) {
$content   = $(\'#ajaxPosts\');
$.ajax({
    url: psc.ajax_url,
    data: {
        action: \'filter_posts\',
        nonce: psc.nonce,
        params: $params
    },
    type: \'post\',
    dataType: \'json\',
success: function(data, textStatus, XMLHttpRequest) {
    if (data.status === 200) {
        $content.html(data.content);
    }
    else if (data.status === 201) {
        $content.html(data.message);    
    }
    else {
        $status.html(data.message);
    }
    },
error: function(MLHttpRequest, textStatus, errorThrown) {
    $status.html(textStatus);
     }
});

functions.php

function psc_filter_posts() {
if( !isset( $_POST[\'nonce\'] ) || !wp_verify_nonce( $_POST[\'nonce\'], \'psc\' ) )
die(\'Permission denied\');

$value = intval($_POST[\'params\'][\'value\']);;
$term = sanitize_text_field($_POST[\'params\'][\'term\']);
$page = intval($_POST[\'params\'][\'page\']);
$qty  = intval($_POST[\'params\'][\'qty\']);

if ( $value == 0 ) : 
    $tax_qry[] = [
        \'taxonomy\' => \'category\',
        \'field\'    => \'term_id\',
        \'terms\'    => $value,
        \'operator\' => \'NOT IN\'
    ];
else :
    $tax_qry[] = [
        \'taxonomy\' => \'category\',
        \'field\'    => \'term_id\',
        \'terms\'    => $value,
    ];
 endif;

//Setup the query args for wp query
$args = [
\'paged\'          => $page,
\'post_status\'    => \'publish\',
\'posts_per_page\' => $qty,
\'tax_query\'      => $tax_qry
];

$qry = new WP_Query($args);

ob_start();
if ($qry->have_posts()) : ?>
    <div class="container">
            <?php while ($qry->have_posts()) : $qry->the_post(); ?>

            LOOP STUFF              

            <?php endwhile; ?>
    </div><!-- .container -->

    <nav class = "container mt-5 text-center">
        <div class="row">
            <div class="col-sm-12">
                <?php psc_ajax_pager($qry,$page,$value); ?>
            </div><!-- .col-sm-12 -->
        </div><!-- .row -->
    </nav>

<?php $response = [
\'status\'=> 200,
\'found\' => $qry->found_posts
];
else :
$response = [
    \'status\'  => 201,
    \'message\' => \'No posts found\'
];

endif;

$response[\'content\'] = ob_get_clean();

die(json_encode($response));

}

add_action(\'wp_ajax_filter_posts\', \'psc_filter_posts\');
add_action(\'wp_ajax_nopriv_filter_posts\', \'psc_filter_posts\');