[WordPress] WordPress Menu Page (And A Submenu Page or Two, Too!)

00-plugins-loaded.php

<?php
add_action( 'plugins_loaded', 'acme_directory_importer' );
/**
 * Starts the plugin.
 *
 * @since 1.0.0
 */
function acme_directory_importer() {

	if ( ! is_admin() ) {
		return;
	}
  
  	// Start the machine...
  
}

01-class-menu.php

<?php

class Menu {
  
	private $settings;

	private $import;
  
	public function __construct( $container ) {

		$this->settings = $container->get( 'settings-page' );
		$this->import   = $container->get( 'import-page' );
	}
  
 	 // Irrelevant code removed, for now.
  
}

02-init-display.php

<?php

public function display() {

	add_menu_page(
		'Settings',
		'Settings',
		'manage_options',
		'acme-directory',
		array( $this->settings, 'display' ),
		'',
		30
	);

	add_submenu_page(
		'acme-directory',
		'Settings',
		'Settings',
		'manage_options',
		'acme-settings',
		array( $this->settings, 'display' )
	);
  
}

03-class-menu.php

<?php

class Menu {
  
	private $settings;
  
	private $import;
  
	public function __construct( $container ) {

		$this->settings = $container->get( 'settings-page' );
		$this->import   = $container->get( 'import-page' );
	}

	public function init() {
		add_action( 'admin_menu', array( $this, 'admin_menu' ) );
	}

	public function admin_menu() {

		add_menu_page(
		'Settings',
		'Settings',
		'manage_options',
		'acme-directory',
		array( $this->settings, 'display' ),
		'',
		30
		);

		add_submenu_page(
		'acme-directory',
		'Settings',
		'Settings',
		'manage_options',
		'acme-settings',
		array( $this->settings, 'display' )
		);
	}
}