HNP Empty Plugin – WordPress Demo Code

Das HNP Empty Plugin ist ein einfaches Demo-Plugin für WordPress, das entwickelt wurde, um grundlegende Funktionen eines Plugins zu demonstrieren. Es zeigt, wie man Styles und Skripte sowohl im Frontend als auch im Backend von WordPress einbindet. Außerdem bietet es eine Benutzeroberfläche zur Verwaltung von Plugin-Optionen über das WordPress-Dashboard. Der Plugin-Demo Code besitzt alle wichtigen Sicherheitsoptionen und Code-Qualitätsanforderungen, damit ein Plugin im offiziellen WordPress Verzeichnis aufgenommen wird. Zudem Funktionen, welche im Jahr 2024 auf dem neuesten Stand sind. Somit eine gute Grundlage für WordPress-Plugin-Entwickler. Geteste Kompatibilität: WordPress 6.5.2 und PHP 8.3. Das Plugin wird aber auch mit neueren und älteren PHP und WordPress Versionen kompatibel sein.

Features:

• Frontend und Backend Styling: Das Plugin fügt sowohl dem Frontend als auch dem Backend von WordPress benutzerdefinierte CSS- und JavaScript-Dateien hinzu, um das Erscheinungsbild anzupassen.
• Plugin-Optionen: Es bietet eine einfache Möglichkeit, Plugin-Optionen über das WordPress-Dashboard zu konfigurieren, einschließlich Textfelder, Zahlenfelder, Farbwähler, Dropdown-Listen und Checkboxen.
• Shortcode: Das Plugin stellt einen Shortcode bereit, mit dem Benutzer die konfigurierten Optionen auf beliebigen Seiten oder Beiträgen anzeigen können.
• Sicherheitsmaßnahmen: Das Plugin implementiert Sicherheitsmaßnahmen wie Nonce-Überprüfung, um unerwünschte Zugriffe auf die Plugin-Einstellungen zu verhindern.

Plugin-Download:

<?php
/*
  Plugin Name: HNP Empty Plugin
  Description: Creates a Demo Plugin in WordPress
  Version: 2.0
  Author: HNP C.R. 
  Author URI: https://homepage-nach-preis.de/
  License: GPLv3
  License URI: https://www.gnu.org/licenses/gpl-3.0.html
 */

// Security check to prevent direct access to the plugin file
defined('ABSPATH') or die('No script kiddies please!');

// Function to enqueue the Frontend CSS and JS
function hnp_empty_plugin_frontend_scripts() {
    // Define a version number
    $version = '2.0';

    // Check if CSS is not already enqueued
    if (!wp_style_is('hnp_empty_plugin_frontend-css')) {
        // Enqueue CSS with the defined version
        wp_enqueue_style('hnp_empty_plugin_frontend-css', plugin_dir_url(__FILE__) . '/frontend/css/hnp_empty_plugin_frontend.css', array(), $version);
    }

    // Check if JavaScript is not already enqueued
    if (!wp_script_is('hnp_empty_plugin_frontend-js')) {
        // Enqueue JavaScript with the defined version
        wp_enqueue_script('hnp_empty_plugin_frontend-js', plugin_dir_url(__FILE__) . '/frontend/js/hnp_empty_plugin_frontend.js', array(), $version, true);
    }
}
add_action('wp_enqueue_scripts', 'hnp_empty_plugin_frontend_scripts');

// Function to enqueue Backend CSS and JS
function hnp_empty_plugin_backend_scripts() {
    // Define a version number
    $version = '2.0';

    // Check if CSS is not already enqueued
    if (!wp_style_is('hnp_empty_plugin_backend-css')) {
        // Enqueue CSS with the defined version
        wp_enqueue_style('hnp_empty_plugin_backend-css', plugin_dir_url(__FILE__) . '/backend/css/hnp_empty_plugin_backend.css', array(), $version);
    }

    // Check if JavaScript is not already enqueued
    if (!wp_script_is('hnp_empty_plugin_backend-js')) {
        // Enqueue JavaScript with the defined version
        wp_enqueue_script('hnp_empty_plugin_backend-js', plugin_dir_url(__FILE__) . '/backend/js/hnp_empty_plugin_backend.js', array(), $version, true);
    }
}
add_action('admin_enqueue_scripts', 'hnp_empty_plugin_backend_scripts');

// Function for Test - with load Options and Fallback
function hnp_empty_plugin_echo_func() {
    // Get option values
    $name = get_option('hnp_empty_plugin_name_field', 'Name');
    $number = get_option('hnp_empty_plugin_number_field', '12');
    $color = get_option('hnp_empty_plugin_color_field', '#ff0000');
    $description = get_option('hnp_empty_plugin_description_field', 'Im a Desc Field');
    $dropdown = get_option('hnp_empty_plugin_dropdown_field', 'option1');
    $checkbox = get_option('hnp_empty_plugin_checkbox_field', 0);

    // Echo option values
    echo '<p>Name Field: ' . esc_html($name) . '</p>';
    echo '<p>Number Field: ' . esc_html($number) . '</p>';
    echo '<p>Color Field: ' . esc_html($color) . '</p>';
    echo '<p>Description Field: ' . esc_html($description) . '</p>';
    echo '<p>Dropdown Field: ' . esc_html($dropdown) . '</p>';
    echo '<p>Checkbox Field: ' . ($checkbox ? 'Enabled' : 'Disabled') . '</p>';
}
add_shortcode('hnp_empty_plugin_echo_func', 'hnp_empty_plugin_echo_func');


// Function to add plugin options to the main menu
function hnp_empty_plugin_add_plugin_options_page() {
    // Check permission
    if (current_user_can('manage_options')) {
        add_menu_page(
            'HNP Empty Plugin Settings',
            'HNP Empty Plugin',
            'manage_options',
            'hnp-empty-plugin-settings',
            'hnp_empty_plugin_render_plugin_options_page',
            plugin_dir_url(__FILE__) . 'img/hnp-favi.png' 
        );
    }
}
add_action('admin_menu', 'hnp_empty_plugin_add_plugin_options_page');


// Function to render plugin options page
function hnp_empty_plugin_render_plugin_options_page() {
    ?>
    <div class="wrap hnp-empty-plugin-settings">
        <h1>HNP Empty Plugin Settings</h1>
        <form method="post" action="options.php">
            <?php settings_fields('hnp_empty_plugin_settings_group'); ?>
            <?php do_settings_sections('hnp-empty-plugin-settings'); ?>
            
            <?php 
                // Add nonce
                wp_nonce_field('hnp_empty_plugin_settings_nonce', 'hnp_empty_plugin_settings_nonce'); 
            ?>
            
            <?php submit_button(); ?>
        </form>
    </div>
    <?php
}

// Function to register plugin options
function hnp_empty_plugin_register_plugin_options() {
    // Name
    add_settings_section(
        'hnp_empty_plugin_name_section',
        'Demo',
        'hnp_empty_plugin_demo_section_callback',
        'hnp-empty-plugin-settings'
    );

    // Name
    add_settings_field(
        'hnp_empty_plugin_name_field', 
        'Name Field', 
        'hnp_empty_plugin_name_field_callback', 
        'hnp-empty-plugin-settings', 
        'hnp_empty_plugin_name_section' 
    );

    // Number
    add_settings_field(
        'hnp_empty_plugin_number_field',
        'Number Field',
        'hnp_empty_plugin_number_field_callback',
        'hnp-empty-plugin-settings',
        'hnp_empty_plugin_name_section'
    );

    // Color
    add_settings_field(
        'hnp_empty_plugin_color_field',
        'Color Field',
        'hnp_empty_plugin_color_field_callback',
        'hnp-empty-plugin-settings',
        'hnp_empty_plugin_name_section'
    );

    // Description
    add_settings_field(
        'hnp_empty_plugin_description_field',
        'Description Field',
        'hnp_empty_plugin_description_field_callback',
        'hnp-empty-plugin-settings',
        'hnp_empty_plugin_name_section'
    );

    // Dropdown
    add_settings_field(
        'hnp_empty_plugin_dropdown_field',
        'Dropdown Field',
        'hnp_empty_plugin_dropdown_field_callback',
        'hnp-empty-plugin-settings',
        'hnp_empty_plugin_name_section'
    );

    // Checkbox
    add_settings_field(
        'hnp_empty_plugin_checkbox_field',
        'Checkbox Field',
        'hnp_empty_plugin_checkbox_field_callback',
        'hnp-empty-plugin-settings',
        'hnp_empty_plugin_name_section'
    );
}
add_action('admin_init', 'hnp_empty_plugin_register_plugin_options');

// Callback function for demo section
function hnp_empty_plugin_demo_section_callback() {
    echo 'This a Demo Plugin. Frontend-Shortcode: &#x5B;hnp_empty_plugin_echo_func]</p>';
}

// Callback function for name field
function hnp_empty_plugin_name_field_callback() {
    $value = get_option('hnp_empty_plugin_name_field', 'Name'); // Fallback value is 'Name'
    echo '<input type="text" name="hnp_empty_plugin_name_field" value="' . esc_attr($value) . '" />';
}

// Callback functions for number fields
function hnp_empty_plugin_number_field_callback() {
    $value = get_option('hnp_empty_plugin_number_field', '12'); // Fallback value is '12'
    echo '<input type="number" name="hnp_empty_plugin_number_field" value="' . esc_attr($value) . '" />';
}

// Callback function for Color Field
function hnp_empty_plugin_color_field_callback() {
    $value = get_option('hnp_empty_plugin_color_field', '#ff0000'); // Fallback value is red color
    echo '<input type="color" name="hnp_empty_plugin_color_field" value="' . esc_attr($value) . '" />';
}

// Callback function for Description Field
function hnp_empty_plugin_description_field_callback() {
    $value = get_option('hnp_empty_plugin_description_field', 'Im a Desc Field'); // Fallback value is 'Im a Desc Field'
    echo '<textarea name="hnp_empty_plugin_description_field">' . esc_html($value) . '</textarea>';
}

// Callback function for dropdown field
function hnp_empty_plugin_dropdown_field_callback() {
    $value = get_option('hnp_empty_plugin_dropdown_field', 'option1'); // Fallback value is 'option1'
    ?>
    <select name="hnp_empty_plugin_dropdown_field">
        <option value="option1" <?php selected($value, 'option1'); ?>>Option 1</option>
        <option value="option2" <?php selected($value, 'option2'); ?>>Option 2</option>
        <option value="option3" <?php selected($value, 'option3'); ?>>Option 3</option>
    </select>
    <?php
}

// Callback function for checkbox field
function hnp_empty_plugin_checkbox_field_callback() {
    $value = get_option('hnp_empty_plugin_checkbox_field', 0); // Fallback value is 0 (not checked)
    ?>
    <label for="hnp_empty_plugin_checkbox_field">
        <input type="checkbox" name="hnp_empty_plugin_checkbox_field" id="hnp_empty_plugin_checkbox_field" value="1" <?php checked($value, 1); ?>>
        Enable Checkbox
    </label>
    <?php
}

// Security measures: Nonce verification and save options
function hnp_empty_plugin_register_security_options() {
    // Check if the current page is our plugin options page
    if (isset($_POST['option_page']) && $_POST['option_page'] == 'hnp_empty_plugin_settings_group') {
        // Check if the nonce is set and valid
        if (!isset($_POST['hnp_empty_plugin_settings_nonce']) || !wp_verify_nonce($_POST['hnp_empty_plugin_settings_nonce'], 'hnp_empty_plugin_settings_nonce')) {
            // Unauthorized request, do not save options
            wp_die('Unauthorized request.'); // Output error message for unauthorized requests
        }

        // Save options
        update_option('hnp_empty_plugin_name_field', $_POST['hnp_empty_plugin_name_field']);
        update_option('hnp_empty_plugin_number_field', sanitize_text_field($_POST['hnp_empty_plugin_number_field']));
        update_option('hnp_empty_plugin_color_field', sanitize_text_field($_POST['hnp_empty_plugin_color_field']));
        update_option('hnp_empty_plugin_description_field', sanitize_textarea_field($_POST['hnp_empty_plugin_description_field']));
        update_option('hnp_empty_plugin_dropdown_field', sanitize_text_field($_POST['hnp_empty_plugin_dropdown_field']));
        update_option('hnp_empty_plugin_checkbox_field', isset($_POST['hnp_empty_plugin_checkbox_field']) ? 1 : 0);
    }
}
add_action('admin_init', 'hnp_empty_plugin_register_security_options');

// Register plugin options and security measures
function hnp_empty_plugin_register_settings() {
    // Register setting and sanitize callback
    register_setting('hnp_empty_plugin_settings_group', 'hnp_empty_plugin_name_field');
    register_setting('hnp_empty_plugin_settings_group', 'hnp_empty_plugin_number_field');
    register_setting('hnp_empty_plugin_settings_group', 'hnp_empty_plugin_color_field');
    register_setting('hnp_empty_plugin_settings_group', 'hnp_empty_plugin_description_field');
    register_setting('hnp_empty_plugin_settings_group', 'hnp_empty_plugin_dropdown_field');
    register_setting('hnp_empty_plugin_settings_group', 'hnp_empty_plugin_checkbox_field');
}
add_action('admin_init', 'hnp_empty_plugin_register_settings');


// Security measures: Nonce verification for options update
function hnp_empty_plugin_validate_settings($input) {
    return $input; // Simply return the input, no further validation here
}