<div class="related_posts">

<p>Похожие материалы</p>

<?php

$tags = wp_get_post_tags($post->ID);

$categories = get_the_category($post->ID);

if (!empty($tags)) {
    
    $tag_ids = array();
    
    foreach ($tags as $individual_tag)
    
        $tag_ids[] = $individual_tag->term_id;
    
    $args = array(
        
        'tag__in' => $tag_ids,
        'orderby' => rand,
        'post__not_in' => array(
        
            $post->ID
        ),
        'showposts' => 4
        
    );
    
    $my_query = new wp_query($args);    
    
    echo '<ul>';
    
    while ($my_query->have_posts()) {
        
        $my_query->the_post();
        
        $title = the_title();
        
        $link = the_permalink();
        
        $thumbnail = the_post_thumbnail();
        
        $trim_title = trim_title_words(7, '...');
        
        echo '<li><a href="' . $link . '" rel="bookmark" title="' . $title . '">' . $thumbnail . '<br />' . $trim_title . '</a></li>';
    }
    
    echo '</ul>';
    
} else {
    
    $category_ids = array();
    
    foreach ($categories as $individual_category)
    
        $category_ids[] = $individual_category->term_id;
    
    $args = array(
        'category__in' => $category_ids,
        'post__not_in' => array(
        
            $post->ID
        ),
        'showposts' => 4,
        'orderby' => rand,
        'caller_get_posts' => 1
    );
    
    $my_query = new wp_query($args);
    
    echo '<ul>';
    
    while ($my_query->have_posts()) {
        
        $my_query->the_post();
        
        $title = the_title();
        
        $link = the_permalink();
        
        $thumbnail = the_post_thumbnail();
        
        $trim_title = trim_title_words(7, '...');
        
        echo '<li><a href="' . $link . '" rel="bookmark" title="' . $title . '">' . $thumbnail . '<br />' . $trim_title . '</a></li>';
    }
    echo '</ul>';
}

wp_reset_query();

?>

</div>