title: Add a DropDown Taxonomy Filter on Archive Page
body: <p>I need to add a taxonomy dropdwon filter in archive page so that I can display the posts assigned to selected taxonomy.</p>
  
  <p>Here is the HTML Output for taxonomies:</p>
  
  <pre><code>&lt;form method="post" action="&lt;?php echo $_SERVER['PHP_SELF']; ?&gt;"&gt;
    &lt;select name="services" id="selectservice" class="postform" onchange="submit();"&gt;
      &lt;option value=""&gt;Select Service&lt;/option&gt;
      &lt;option value="intensive-support"&gt;Intensive Support&lt;/option&gt;
      &lt;option value="recovery-work"&gt;Recovery Work&lt;/option&gt;
      &lt;option value="tenant-support"&gt;Tenant Support&lt;/option&gt;
    &lt;/select&gt;
  &lt;/form&gt;
  </code></pre>
  
  <p>Below is the Query Code :</p>
  
  <pre><code>&lt;table class="dataTable"&gt;
      &lt;tr&gt;
        &lt;th&gt;Name&lt;/th&gt;
        &lt;th&gt;Location&lt;/th&gt;
        &lt;th&gt;Website&lt;/th&gt;
        &lt;th&gt;Service(s)&lt;/th&gt;
      &lt;/tr&gt;
      &lt;?php $service_query = new WP_Query('post_type=ptype_service&amp;posts_per_page=-1'); ?&gt;
      &lt;?php $j = 0 ?&gt;
      &lt;?php while ($service_query-&gt;have_posts()) : $service_query-&gt;the_post(); ?&gt;
      &lt;?php $additional_class = (++$j % 2 == 0) ? 'even' : 'odd'; ?&gt;
      &lt;tr class="&lt;?php echo $additional_class ?&gt;"&gt;
        &lt;td&gt;&lt;?php the_title()?&gt;&lt;/td&gt;
        &lt;td&gt;&lt;?php echo (get_post_meta($post-&gt;ID, 'pir_groups_location', true))?&gt;&lt;/td&gt;
        &lt;td&gt;&lt;a target="_blank" href="http://&lt;?php echo (get_post_meta($post-&gt;ID, 'pir_groups_website', true))?&gt;"&gt;&lt;?php echo (get_post_meta($post-&gt;ID, 'pir_groups_website', true))?&gt;&lt;/a&gt;&lt;/td&gt;
        &lt;td&gt;
          &lt;?php
          $terms = get_the_terms( $post-&gt;ID, 'services' );
          if ( $terms &amp;&amp; ! is_wp_error( $terms ) ) :      
              $services_links = array();  
              foreach ( $terms as $term ) {
                  $services_links[] = $term-&gt;name;
              }                               
              $on_draught = join( ", ", $services_links );
          ?&gt;
          &lt;?php echo $on_draught; ?&gt;
          &lt;?php endif; ?&gt;
        &lt;/td&gt;
      &lt;/tr&gt;
      &lt;?php endwhile; ?&gt;
    &lt;/table&gt;
  </code></pre>
  
  <p>Regards</p>