Plugin Development from Scratch: Adding Menus and Submenus to the Administrative Panel

WordPress is a powerful and flexible platform that allows users to expand its functionality through the use of plugins. Developing a plugin from scratch may seem like a daunting task, but with a little knowledge of PHP and the WordPress API, you can create custom tools that integrate seamlessly with your WordPress admin panel. One of the most common features when developing plugins is the addition of menus and submenus in the administrative panel, which allow users to interact with the new functionalities offered by your plugin.

Understanding the Menu Structure in WordPress

Before we start adding menus and submenus, it's important to understand how WordPress organizes these elements. The WordPress admin panel is divided into several sections, each with its own menus and submenus. These sections include posts, media, pages, comments, appearance, plugins, users, tools and settings.

Menus are the main options that appear in the sidebar of the administrative panel, and submenus are additional options that unfold from a main menu. When developing a plugin, you can choose to add your own main menu or insert submenus into existing menus.

Adding a Main Menu

To add a new main menu to the admin panel, you will use the add_menu_page() function. This function accepts several parameters that define the page title, the menu title, the capabilities needed to access the menu, the menu slug, the callback function that renders the page content, the menu icon, and the menu position in the sidebar.

function my_plugin_add_menu() {
    add_menu_page(
        'Plugin Page Title', // Page title
        'My Plugin', // Menu title
        'manage_options', // Required capacity
        'my-plugin-slug', // Menu slug
        'my_plugin_render_page', // Callback function
        'dashicons-admin-generic', // Menu icon
        6 // Menu position
    );
}
add_action('admin_menu', 'my_plugin_add_menu');

The my_plugin_renderize_pagina() callback function is where you will place the HTML and PHP needed to display the content of your menu page. Here is a simple example of how this function might be structured:

function my_plugin_render_page() {
    ?>
    

        
My Plugin Settings
        

            
            
        
    
    

function my_plugin_add_submenu() {
    add_submenu_page(
        'options-general.php', // Main menu slug
        'Plugin Submenu Settings', // Page title
        'Plugin submenu', // Menu title
        'manage_options', // Required capacity
        'my-plugin-submenu-slug', // Submenu slug
        'my_plugin_render_subpage' // Callback function
    );
}
add_action('admin_menu', 'my_plugin_add_submenu');