Related posts by tagging

shortcode.php

add_shortcode( 'tag-relations', 'posts_relations_by_tags' );
/**
 *Renders all post relations defined by tags-relation
 * 
 * @author Floris P. Lof
 */
function posts_relations_by_tags() {

	$found_posts = false;
	$found_posts_ids = array();
	$max_posts = 10;

	$tags = wp_get_object_terms( get_the_id(), 'post_tag', array( 'fields' => 'ids' ) );

	if ( ! is_array( $tags ) || ( empty( $tags ) ) ) {
		return;
	}

	// The args
	$args = array(
		'posts_per_page'	=> $max_posts,
		'tag__in'			=> $tags,
		'post__not_in'		=> array( get_the_id() ),
		'cache_results'		=> false,
		'no_found_rows'		=> true,
	);

	// The Query
	$the_query = new WP_Query( $args );

	// The Loop
	if ( $the_query->have_posts() ) {

		$list		= '';
		$found_posts	= true;

		while ( $the_query->have_posts() ) {
			$the_query->the_post();

			$list .= '<li><a href="' . get_permalink() . '" title="' . esc_attr( get_the_title() ) . '">&raquo; ' . get_the_title() . '</a></li>';
		}
	} 

	/* Restore original Post Data */
	wp_reset_postdata();	

	if ( $found_posts ) {
		$html = '';

		$html .= '<h4 class="widget-title">' . __( 'Related articles', 'fpl-child-theme' ) . '</h4>';
		$html .= '<ul class="related-posts">';
		$html .= 	$list;
		$html .= '</ul>';

		return $html;
	}
	
	return '';

}