child taxonomy and it's template

hi there, i have a taxonomy called “brand” with child taxonomies of cities like “koeln” linked to a custom post type called “distributors” where i can add shops with name, address and so on.

since i create a link to the list of cities of each brand on another custom post type, called “marken”, i (think i have to) pass a variable with GET to check on which page of “marken” i am.

that works pretty good, and by clicking on the main link, the list of cities for the dependend brand is listed. now my problem:

by clicking on a city name, each entry of “distributors” linked to it shall show custom fields like the name, address, etc.

this works ONLY if i save a new file for the child taxonomy, as example: “taxonomy-{taxname}-{name-of-child-tax}.php” or in detail “taxonomy-brand-koeln-welder.php”.

the problem is the huge amount of child taxonomies and that i have to edit all of them if i want to make a change to the template…

i tried it with conditional tags, like asking if it’s a parent page and so on… here you can see the actual example. and sorry for my messy code – i’m not working that long with wordpress and php:

<?php get_header(); ?>
<?php
$queried_object = get_queried_object();
$current_id = $queried_object->term_id;
$current_slug = $queried_object->slug;
?>
<?php if($term->parent > 0) { // here begins the part of the child taxonomy output ?>
<?php

$args=array(
  'name' => $current_slug,
  'post_type' => 'marken',
  'post_status' => 'publish',
  'showposts' => 1,
  'caller_get_posts'=> 1
);

$my_posts = get_posts($args);
if( $my_posts ) {
$my_id = $my_posts[0]->ID;
echo '<div id="single-brand">';
echo '<div class="headline"><h2 class="line"><span class="white-bg"><img src="'.get_field('logo', $my_id).'" alt="'.get_the_title($my_id).'" ></span></h2></div></div>';
}
wp_reset_query();
$args = array(
  'post_type'   => 'distributors',
  'tax_query' => array(
		array(
			'taxonomy' => 'brand',
		)
	)
);
?>
<?php $query = new WP_Query( $args ); ?>
<?php if ( have_posts() ) : while ( have_posts() ) : the_post(); ?>
<?php if( has_term( $current_slug, 'brand' ) ) {?>
<div class="distributor">
<table><tr><td>
<img src="<?php bloginfo('template_directory'); ?>/images/icon-pin-big.png" alt="<?php the_title(); ?>" />
</td>
<td>
<h2><?php the_title(); ?></h2>
<p><?php the_field('distributor_address'); ?></p>
<p>Tel. <?php the_field('distributor_phone'); ?><br>
Fax <?php the_field('distributor_fax'); ?></p>
</td></tr></table>
<a href="http://<?php the_field('distributor_web'); ?>" class="button" target="_blank">Shopseite besuchen</a>
</div>
<?php } endwhile; endif; ?>
<?php wp_reset_query(); ?>
<a href="<?php bloginfo('url'); ?>/index.php/brand/<?php echo $current_slug; ?>/" >Zurück zur Händlerliste</a>	

<?php
}
else // here begins the list of the cities {
$args=array(
  'name' => $current_slug,
  'post_type' => 'marken',
  'post_status' => 'publish',
  'showposts' => 1,
  'caller_get_posts'=> 1
);
$my_posts = get_posts($args);
if( $my_posts ) {
$my_id = $my_posts[0]->ID;
echo '<div id="single-brand">';
echo '<div class="headline"><h2 class="line"><span class="white-bg"><img src="'.get_field('logo', $my_id).'" alt="'.get_the_title($my_id).'" ></span></h2></div></div>';
}
wp_reset_query();

$args=array(
  'post_type' => 'distributors',
  'post_status' => 'publish',
  'showposts' => 1,
  'tax_query' => array(
        array(
            'taxonomy' => 'brand',
            'field' => 'slug',
            'terms' => $current_slug
        )
    )
);
$my_posts = get_posts($args);
if( $my_posts ) {
	$term_id = $current_id;
	$taxonomyName = "brand";
	$termchildren = get_term_children( $term_id, $taxonomyName );
echo '<h3>Händlerliste</h3>';
echo '<ul>';
foreach ($termchildren as $child) {
    $term = get_term_by( 'id', $child, $taxonomyName );
	$term_link = get_term_link( $term, $taxonomyName );
echo '<li><a href="'.$term_link.'?marke='.$current_slug.'">'.$term->name.'</a></li>';
}
echo '</ul>';
}}	?>
<?php get_footer(); ?>

the conditional “if($term->parent > 0)” works for the list of cities, but the output of child taxonomy is not shown. is there anything wrong with all my queries? as i said: when i make a separate file for the child taxonomy with the first code part, everything works… i really despair of it 🙁

thx in advance