How to Add Breadcrumbs to Your WordPress Theme Easily

Code

<?php
// Add breadcrumbs to WordPress theme

// Hook the breadcrumbs function to an appropriate action
add_action('wp_dudecom_breadcrumbs', 'wp_dudecom_display_breadcrumbs');

/**
 * Display breadcrumbs navigation
 */
function wp_dudecom_display_breadcrumbs() {
    // Security check: Ensure this is not accessed directly
    if (!defined('ABSPATH')) {
        exit;
    }

    // Start the breadcrumbs output
    echo '<nav class="wp-dudecom-breadcrumbs" aria-label="breadcrumb">';
    echo '<ul>';

    // Home link
    echo '<li><a href="' . esc_url(home_url('/')) . '">' . esc_html__('Home', 'textdomain') . '</a></li>';

    // Check if we are on a category, tag, or custom taxonomy archive
    if (is_category() || is_tag() || is_tax()) {
        $term = get_queried_object();
        if ($term->parent != 0) {
            $ancestors = array_reverse(get_ancestors($term->term_id, $term->taxonomy));
            foreach ($ancestors as $ancestor) {
                $ancestor_term = get_term($ancestor, $term->taxonomy);
                echo '<li><a href="' . esc_url(get_term_link($ancestor_term)) . '">' . esc_html($ancestor_term->name) . '</a></li>';
            }
        }
        echo '<li>' . esc_html($term->name) . '</li>';
    }

    // Check if we are on a single post
    elseif (is_single()) {
        $post_type = get_post_type();
        if ($post_type != 'post') {
            $post_type_object = get_post_type_object($post_type);
            echo '<li><a href="' . esc_url(get_post_type_archive_link($post_type)) . '">' . esc_html($post_type_object->labels->singular_name) . '</a></li>';
        }
        $categories = get_the_category();
        if ($categories) {
            $category = $categories[0];
            $ancestors = array_reverse(get_ancestors($category->term_id, 'category'));
            foreach ($ancestors as $ancestor) {
                $ancestor_category = get_category($ancestor);
                echo '<li><a href="' . esc_url(get_category_link($ancestor_category)) . '">' . esc_html($ancestor_category->name) . '</a></li>';
            }
            echo '<li><a href="' . esc_url(get_category_link($category)) . '">' . esc_html($category->name) . '</a></li>';
        }
        echo '<li>' . esc_html(get_the_title()) . '</li>';
    }

    // Check if we are on a page
    elseif (is_page()) {
        global $post;
        if ($post->post_parent) {
            $ancestors = array_reverse(get_post_ancestors($post->ID));
            foreach ($ancestors as $ancestor) {
                echo '<li><a href="' . esc_url(get_permalink($ancestor)) . '">' . esc_html(get_the_title($ancestor)) . '</a></li>';
            }
        }
        echo '<li>' . esc_html(get_the_title()) . '</li>';
    }

    // Check if we are on a search page
    elseif (is_search()) {
        echo '<li>' . esc_html__('Search results for:', 'textdomain') . ' ' . esc_html(get_search_query()) . '</li>';
    }

    // Check if we are on a 404 page
    elseif (is_404()) {
        echo '<li>' . esc_html__('Error 404', 'textdomain') . '</li>';
    }

    echo '</ul>';
    echo '</nav>';
}

/**
 * Function to display breadcrumbs
 */
function wp_dudecom_get_breadcrumbs() {
    do_action('wp_dudecom_breadcrumbs');
}
?>