How to display related posts on your WordPress site

Here is a code snippet that registers a new shortcode you can embed on all the posts where you want to display the nice cards with related content.

<?php
declare( strict_types = 1 );
namespace IuliaCazanSnippets\RelatedContent;
\add_shortcode( 'lps_related_articles', __NAMESPACE__ . '\\lps_related_articles', 10 );

/**
 * Related articles shortcode.
 * Snippet by Iulia Cazan - https://iuliacazan.ro.
 * 
 * @param  array $args Shortcode arguments.
 * @return string
 */
function lps_related_articles( $args ): string {
	$args = \wp_parse_args( $args, [
		'taxonomy' => '',
		'terms'    => '',
		'search'   => '',
		'limit'    => 4,
		'display'  => 'title,content-small',
	] );

	// You can put here the LPS shortcode base you want to use.
	$base = 'latest-selected-content ver="2" limit="' . (int) $args['limit'] . '" display="' . \esc_attr( $args['display'] ) . '" titletag="h4" chrlimit="160" more="…" url="yes" image="thumbnail" elements="25" css="four-columns as-column has-shadow hover-zoom content-space-between light has-img-spacing" type="post" status="publish" orderby="dateD" show_extra="trim"';

	if ( ! empty( $args['search'] ) ) {
		$base  .= ' search="' . \esc_attr( $args['search'] ) . '"';
		$result = \do_shortcode( '[' . $base . ']' );
	} elseif ( ! empty( $args['taxonomy'] ) ) {
		if ( empty( $args['terms'] ) ) {
			// Get dynamically the current post taxonomy terms.
			$tax_terms = \wp_get_object_terms( \get_the_ID(), $args['taxonomy'], [ 'fields' => 'all' ] );
			if ( ! empty( $tax_terms ) && ! \is_wp_error( $tax_terms ) ) {
				$slugs = \wp_list_pluck( $tax_terms, 'slug' );
				$terms = implode( ',', $slugs );
			}
		} else {
			// Specified taxonomy terms.
			$terms = $args['terms'];
		}

		if ( ! empty( $terms ) ) {
			$base  .= ' taxonomy="' . \esc_attr( $args['taxonomy'] ) . '" term="' . \esc_attr( $terms ) . '"';
			$result = \do_shortcode( '[' . $base . ']' );
		}
	}

	if ( ! empty( $result ) ) {
		return '<h2>' . \__( 'Related Articles', 'lps' ) . '</h2>' . $result;
	}

	return '';
}