Tutorial : WordPress – Custom Author & Contributor Page

<?php
/*
Plugin Name: EasyCodingWithAI - Custom User Page
Description: Overrides the default WordPress user page with a custom template, flags users who edit posts as contributors, and adds a shortcode to display authors and contributors. Contributors are now stored in a custom database table.
Version: 1.5
Author: EasyCodingWithAI
*/

// Create a custom table on plugin activation
function easycoding_create_contributors_table() {
    global $wpdb;
    $table_name = $wpdb->prefix . 'post_contributors';

    // Check if table exists
    if ($wpdb->get_var("SHOW TABLES LIKE '$table_name'") != $table_name) {
        // Create the table if it does not exist
        $charset_collate = $wpdb->get_charset_collate();
        $sql = "CREATE TABLE $table_name (
            id bigint(20) UNSIGNED NOT NULL AUTO_INCREMENT,
            post_id bigint(20) UNSIGNED NOT NULL,
            user_id bigint(20) UNSIGNED NOT NULL,
            PRIMARY KEY (id),
            UNIQUE KEY post_user (post_id, user_id)
        ) $charset_collate;";

        require_once(ABSPATH . 'wp-admin/includes/upgrade.php');
        dbDelta($sql);
    }
}
register_activation_hook(__FILE__, 'easycoding_create_contributors_table');

// Redirect author page to custom template
add_action('template_redirect', 'easycoding_custom_user_page_redirect');
function easycoding_custom_user_page_redirect() {
    if (is_author()) {
        include(plugin_dir_path(__FILE__) . 'templates/template-author.php');
        exit();
    }
}

// Enqueue CSS for the custom author page
function easycoding_custom_user_page_styles() {
    if (is_author()) {
        wp_enqueue_style('easycoding-author-page-style', plugin_dir_url(__FILE__) . 'assets/css/easycoding-user-enhancements.css');
    }
}
add_action('wp_enqueue_scripts', 'easycoding_custom_user_page_styles');

// Mark users who edit posts as contributors and store in the custom table
add_action('save_post', 'easycoding_mark_contributor_on_edit', 10, 3);
function easycoding_mark_contributor_on_edit($post_id, $post, $update) {
    // Don't run on autosave or if this is a revision
    if (defined('DOING_AUTOSAVE') && DOING_AUTOSAVE) return;
    if ($post->post_type == 'revision') return;

    // Get the user who edited the post
    $user_id = get_current_user_id();
    if ($user_id > 0) {
        global $wpdb;
        $table_name = $wpdb->prefix . 'post_contributors';

        // Check if the user is already a contributor for this post
        $existing_contributor = $wpdb->get_var($wpdb->prepare(
            "SELECT user_id FROM $table_name WHERE post_id = %d AND user_id = %d",
            $post_id,
            $user_id
        ));

        if (!$existing_contributor) {
            // Add user as a contributor
            $wpdb->insert(
                $table_name,
                array(
                    'post_id' => $post_id,
                    'user_id' => $user_id
                )
            );
        }
    }
}

// Add "Contributors" column to the posts list in admin
add_filter('manage_posts_columns', 'easycoding_add_contributors_column');
function easycoding_add_contributors_column($columns) {
    $columns['contributors'] = 'Contributors';
    return $columns;
}

// Display the contributors in the new column
add_action('manage_posts_custom_column', 'easycoding_show_contributors_in_column', 10, 2);
function easycoding_show_contributors_in_column($column_name, $post_id) {
    if ($column_name == 'contributors') {
        global $wpdb;
        $table_name = $wpdb->prefix . 'post_contributors';

        // Get all contributors for the post
        $contributors = $wpdb->get_results($wpdb->prepare(
            "SELECT user_id FROM $table_name WHERE post_id = %d",
            $post_id
        ));

        if ($contributors) {
            // Get the display names of contributors
            $main_author_id = get_post_field('post_author', $post_id);
            $contributors = array_map(function($contributor) {
                $user = get_user_by('id', $contributor->user_id);
                return $user ? $user->display_name : 'Unknown Contributor';
            }, $contributors);

            // Exclude the main author
            $contributors = array_diff($contributors, [get_user_by('id', $main_author_id)->display_name]);

            echo implode(', ', $contributors);
        } else {
            echo 'No contributors';
        }
    }
}

// Shortcode to display the main author and additional contributors
add_shortcode('contributors_list', 'easycoding_contributors_list_shortcode');
function easycoding_contributors_list_shortcode($atts) {
    global $post;

    $post_id = $post->ID;
    $main_author_id = $post->post_author;
    $main_author = get_user_by('id', $main_author_id);

    // Get contributors from the custom table
    global $wpdb;
    $table_name = $wpdb->prefix . 'post_contributors';
    $contributors = $wpdb->get_results($wpdb->prepare(
        "SELECT user_id FROM $table_name WHERE post_id = %d",
        $post_id
    ));

    $output = '';

    if ($main_author) {
        // Make the main author's name a clickable link to their author page
        $output .= '<strong>Authored by:</strong> <a href="' . get_author_posts_url($main_author->ID) . '">' . esc_html($main_author->display_name) . '</a>';
    }

    if ($contributors) {
        // Exclude the main author from the list of contributors
        $contributors = array_filter($contributors, function($contributor) use ($main_author_id) {
            return $contributor->user_id != $main_author_id;
        });

        if ($contributors) {
            // Map contributors to profile links
            $contributors = array_map(function($contributor) {
                $user = get_user_by('id', $contributor->user_id);
                if ($user) {
                    return '<a href="' . get_author_posts_url($user->ID) . '">' . esc_html($user->display_name) . '</a>';
                }
                return 'Unknown Contributor';
            }, $contributors);

            $output .= '<br><strong>Additional contributions by:</strong> ' . implode(', ', $contributors);
        }
    }

    return $output;
}

// Add the contributors meta box to the post editor
add_action('add_meta_boxes', 'easycoding_add_contributors_meta_box');
function easycoding_add_contributors_meta_box() {
    add_meta_box(
        'contributors_meta_box',
        'Contributors',
        'easycoding_contributors_meta_box_callback',
        'post',
        'side',
        'default'
    );
}

function easycoding_contributors_meta_box_callback($post) {
    global $wpdb;
    $table_name = $wpdb->prefix . 'post_contributors';

    // Get contributors for this post (including the author)
    $contributors = $wpdb->get_results($wpdb->prepare(
        "SELECT user_id FROM $table_name WHERE post_id = %d",
        $post->ID
    ));

    $main_author_id = $post->post_author;

    // Filter out the main author from the contributors list
    $contributors = array_filter($contributors, function($contributor) use ($main_author_id) {
        return $contributor->user_id != $main_author_id;
    });

    // Check if we have contributors (excluding the main author)
    if ($contributors && count($contributors) > 0) {
        echo '<ul>';
        foreach ($contributors as $contributor) {
            $user = get_user_by('id', $contributor->user_id);
            if ($user) {
                echo '<b><li>' . esc_html($user->display_name) . '</li></b>';
            }
        }
        echo '</ul>';
    } else {
        // If no contributors exist and the post author is the only one, show "No contributors yet."
        echo '<p>No other users have contributed to this post.</p>';

    }
}

?>

<?php
/* Template for displaying custom author pages */

get_header();

// Get the queried author object
$author = get_queried_object();
?>

<div class="custom-author-page">
    <div class="author-header">
        <?php echo get_avatar($author->ID, 120); // Display avatar with size 120px ?>
        <div class="author-details">
            <h1><?php echo esc_html($author->display_name); ?></h1>
            <p><?php echo esc_html($author->description); ?></p>
        </div>
    </div>

    <h2>Posts by <?php echo esc_html($author->display_name); ?></h2>
    <ul>
        <?php
        // Query to get posts authored by the author
        $args = array(
            'author' => $author->ID,
            'posts_per_page' => 10,
        );
        $author_posts = new WP_Query($args);

        if ($author_posts->have_posts()) {
            while ($author_posts->have_posts()) {
                $author_posts->the_post();
                echo '<li><a href="' . get_permalink() . '">' . get_the_title() . '</a></li>';
            }
        } else {
            echo '<p>No posts by this author.</p>';
        }
        wp_reset_postdata();
        ?>
    </ul>

    <h2>Posts Contributed To</h2>
    <ul>
        <?php
        // Query to get posts contributed to by this author
        global $wpdb;

        // Prepare the SQL query to select posts where the author is a contributor
$query = "
    SELECT p.ID, p.post_title
    FROM {$wpdb->posts} p
    INNER JOIN {$wpdb->prefix}post_contributors c ON p.ID = c.post_id
    WHERE c.user_id = %d
    AND p.post_author != c.user_id
    LIMIT 10
";



        // Prepare the SQL query for this author
        $results = $wpdb->get_results($wpdb->prepare($query, $author->ID));

        if ($results) {
            foreach ($results as $post) {
                echo '<li><a href="' . get_permalink($post->ID) . '">' . esc_html($post->post_title) . '</a></li>';
            }
        } else {
            echo '<p>No posts contributed to by this author.</p>';
        }
        ?>
    </ul>
</div>

<?php get_footer(); ?>

/* Custom styles for the author page */
.custom-author-page {
    max-width: 1024px;
    margin: 0 auto;
    box-sizing: border-box;
    width:100%;
    padding: 20px;
}

.custom-author-page h1 {
    font-size: 2em;
    color: #333;
}

.custom-author-page ul {
    list-style-type: none;
    padding: 0;
}

.custom-author-page ul li {
    margin: 10px 0;
}

.custom-author-page a {
    text-decoration: none;
    color: #0073aa;
}

.custom-author-page a:hover {
    color: #005177;
}
/* Styling for the author header with avatar and details */
.author-header {
    display: flex;
    align-items: center;
    margin-bottom: 20px;
}

.author-header img.avatar {
    width: 120px;
    height: 120px;
    border-radius: 50%;
    margin-right: 20px;
}

.author-details {
    display: flex;
    flex-direction: column;
}

.author-details h1 {
    margin: 0;
}

.author-details p {
    margin: 8px 0 0;
    color: #666;
    font-size: 1em;
}