Related Posts Plugin Generated by AI - Version 1

speckyboy-related-posts.php

<?php
/*
Plugin Name: Speckyboy Related Posts
Plugin URI:  https://speckyboy.com/
Description: Displays related posts based on categories and tags at the bottom of each post.
Version:     1.0
Author:      Eric Karkovack
Author URI:  https://karks.com/
License:     GPL2
*/

if (!defined('ABSPATH')) exit; // Exit if accessed directly

function rpd_get_related_posts($post_id) {
    $categories = wp_get_post_categories($post_id);
    $tags = wp_get_post_tags($post_id, array('fields' => 'ids'));

    if (empty($categories) && empty($tags)) {
        return []; // No categories or tags, return empty array
    }

    $args = [
        'post_type'      => 'post',
        'post_status'    => 'publish',
        'posts_per_page' => 4,
        'post__not_in'   => [$post_id],
        'orderby'        => 'rand',
        'tax_query'      => [
            'relation' => 'OR',
        ]
    ];

    if (!empty($categories)) {
        $args['tax_query'][] = [
            'taxonomy' => 'category',
            'field'    => 'term_id',
            'terms'    => $categories,
        ];
    }
    
    if (!empty($tags)) {
        $args['tax_query'][] = [
            'taxonomy' => 'post_tag',
            'field'    => 'term_id',
            'terms'    => $tags,
        ];
    }

    $query = new WP_Query($args);
    return $query->posts;
}

function rpd_display_related_posts($content) {
    if (!is_single() || !in_the_loop() || !is_main_query()) {
        return $content;
    }

    global $post;
    $related_posts = rpd_get_related_posts($post->ID);

    if (empty($related_posts)) {
        return $content;
    }

    $output = '<div class="related-posts"><h3>Related Posts</h3><ul>';
    foreach ($related_posts as $related) {
        $output .= '<li><a href="' . get_permalink($related->ID) . '">' . esc_html(get_the_title($related->ID)) . '</a></li>';
    }
    $output .= '</ul></div>';

    return $content . $output;
}
add_filter('the_content', 'rpd_display_related_posts');