Tutorial : WordPress – Custom Icon Shortcodes

<?php
/**
 * Plugin Name: EasyCodingWithAI - Custom Icon Shortcodes
 * Description: Allows users to insert icons in posts using HTML entities. Comes with an admin panel for managing icon mappings.
 * Version: 1.0
 * Author: EasyCodingWithAI
 */

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

// Create the database table on plugin activation.
function easycoding_custom_icons_install() {
    global $wpdb;

    $table_name = $wpdb->prefix . 'custom_icons'; // Table name
    $charset_collate = $wpdb->get_charset_collate();

    // SQL to create the table
    $sql = "CREATE TABLE $table_name (
        id mediumint(9) NOT NULL AUTO_INCREMENT,
        name tinytext NOT NULL,
        entity_code text NOT NULL,
        PRIMARY KEY  (id)
    ) $charset_collate;";

    // Include the WordPress file to handle database operations
    require_once(ABSPATH . 'wp-admin/includes/upgrade.php');

    // Create the table and handle errors
    if ($wpdb->get_var("SHOW TABLES LIKE '$table_name'") != $table_name) {
        if (!dbDelta($sql)) {
            error_log("Database table creation failed for $table_name");
        }
    }

    // Pre-install some common icons
    $icons = [
        ['name' => 'heart', 'entity_code' => '♥'],
        ['name' => 'star', 'entity_code' => '&star;'],
        // Add more icons as needed
    ];

    foreach ($icons as $icon) {
        $wpdb->insert($table_name, $icon);
    }
}
register_activation_hook(__FILE__, 'easycoding_custom_icons_install');

// Register the shortcode
function easycoding_custom_icon_shortcode($atts) {
    global $wpdb;

    // Extract shortcode attributes
    $atts = shortcode_atts(['name' => ''], $atts);
    $name = sanitize_text_field($atts['name']);

    // Retrieve the icon from the database
    $table_name = $wpdb->prefix . 'custom_icons';
    $icon = $wpdb->get_row($wpdb->prepare("SELECT entity_code FROM $table_name WHERE name = %s", $name));

    // Check if the icon exists
    if ($icon) {
        return $icon->entity_code; // Return the HTML entity
    } else {
        error_log("Icon not found: $name");
        return ''; // Return an empty string if the icon is not found
    }
}
add_shortcode('icon', 'easycoding_custom_icon_shortcode');

// Create the admin menu
function easycoding_custom_icons_menu() {
    add_menu_page('Custom Icons', 'Custom Icons', 'manage_options', 'easycoding-custom-icons', 'easycoding_custom_icons_admin_page');
}
add_action('admin_menu', 'easycoding_custom_icons_menu');

// Admin page for managing icons
function easycoding_custom_icons_admin_page() {
    global $wpdb;
    $table_name = $wpdb->prefix . 'custom_icons';

    // Handle form submissions
    if ($_SERVER['REQUEST_METHOD'] == 'POST') {
        if (isset($_POST['add_icon'])) {
            $name = sanitize_text_field($_POST['icon_name']);
            $entity_code = wp_kses_post($_POST['icon_entity_code']);
            $wpdb->insert($table_name, ['name' => $name, 'entity_code' => $entity_code]);
            echo '<div class="notice notice-success is-dismissible"><p>Icon added successfully!</p></div>';
        } elseif (isset($_POST['delete_icon'])) {
            $id = intval($_POST['icon_id']);
            $wpdb->delete($table_name, ['id' => $id]);
            echo '<div class="notice notice-success is-dismissible"><p>Icon deleted successfully!</p></div>';
        }
    }

    // Fetch existing icons
    $icons = $wpdb->get_results("SELECT * FROM $table_name");
    ?>
    <div class="wrap">
        <h1 class="wp-heading-inline">Custom Icons</h1>
        <form method="post" class="post">
            <h2>Add New Icon</h2>
            <table class="form-table">
                <tr>
                    <th scope="row"><label for="icon_name">Icon Name</label></th>
                    <td><input type="text" name="icon_name" id="icon_name" required></td>
                </tr>
                <tr>
                    <th scope="row"><label for="icon_entity_code">HTML Entity Code</label></th>
                    <td><input type="text" name="icon_entity_code" id="icon_entity_code" required></td>
                </tr>
            </table>
            <?php submit_button('Add Icon', 'primary', 'add_icon'); ?>
        </form>

        <h2>Existing Icons</h2>
        <table class="wp-list-table widefat striped">
            <thead>
                <tr>
                    <th>ID</th>
                    <th>Name</th>
                    <th>Entity Code</th>
                    <th>Action</th>
                </tr>
            </thead>
            <tbody>
                <?php if ($icons): foreach ($icons as $icon): ?>
                    <tr>
                        <td><?php echo esc_html($icon->id); ?></td>
                        <td><?php echo esc_html($icon->name); ?></td>
                        <td><?php echo esc_html($icon->entity_code); ?></td>
                        <td>
                            <form method="post" style="display:inline;">
                                <input type="hidden" name="icon_id" value="<?php echo esc_attr($icon->id); ?>">
                                <?php submit_button('Delete', 'secondary', 'delete_icon', false); ?>
                            </form>
                        </td>
                    </tr>
                <?php endforeach; else: ?>
                    <tr>
                        <td colspan="4">No icons found.</td>
                    </tr>
                <?php endif; ?>
            </tbody>
        </table>
    </div>
    <?php
}
?>