根据下拉选择在同一页面上显示内容

Question

此代码目前无效。我正在使用wordpress并尝试根据所选的下拉列表显示内容。更具体地说，内容是基于分类法的不同循环。

<form method="post" action="">
<select name="only_criteria" onchange="submit();">
        <option selected="selected">Please Choose</option>
        <option value="one">One</option>
        <option value="two">Two</option>
        <option value="three">Three</option>
</select>
</form>

<div class="archive-wrap">
 <div class="carousel">
<?php 
 if(isset($_POST['only_criteria']) && $_POST['only_criteria'] == '')  {   
$loop = new WP_Query( array( 
    'post_type' => 'my_custom_post_type',
    'posts_per_page' => -1,
    'tax_query' => array(
        'relation' => 'AND',
            array(
                'taxonomy' => 'my_taxonomy',
                'terms'    => array( 'tax_one','tax_two','tax_three'),
      ),
    ),
  ) );
  } else if(isset($_POST['only_criteria']) && $_POST['only_criteria'] == 'one')  {   
$loop = new WP_Query( array( 
    'post_type' => 'my_custom_post_type',
    'posts_per_page' => -1,
    'tax_query' => array(
        'relation' => 'AND',
            array(
                'taxonomy' => 'my_taxonomy',
                'terms'    => array( 'tax_one'),
      ),
    ),
  ) );
  } else if(isset($_POST['only_criteria']) && $_POST['only_criteria'] == 'two')  {   
$loop = new WP_Query( array( 
    'post_type' => 'my_custom_post_type',
    'posts_per_page' => -1,
    'tax_query' => array(
        'relation' => 'AND',
            array(
                'taxonomy' => 'my_taxonomy',
                'terms'    => array( 'tax_two'),
      ),
    ),
  ) );
  } else if(isset($_POST['only_criteria']) && $_POST['only_criteria'] == 'three')  {   
$loop = new WP_Query( array( 
    'post_type' => 'my_custom_post_type',
    'posts_per_page' => -1,
    'tax_query' => array(
        'relation' => 'AND',
            array(
                'taxonomy' => 'my_taxonomy',
                'terms'    => array('tax_three'),
      ),
    ),
  ) );
  }
?>

我通过将每个循环放在一个标签中来完成与标签类似的事情。我希望使用该表单，因为我认为它会减少加载时间并提高效率。