felixarntz/oop-admin-pages

<?php
/**
 * WordPress_Admin_Submenu_Page class
 *
 * @package Leaves_And_Love\OOP_Admin_Pages\Admin_Page
 * @since 1.0.0
 */

namespace Leaves_And_Love\OOP_Admin_Pages\Admin_Page;

/**
 * Class representing a WordPress admin page that also has a submenu entry.
 *
 * @since 1.0.0
 */
class WordPress_Admin_Submenu_Page extends WordPress_Admin_Page {

    const PARENT_SLUG = 'parent_slug';
    const MENU_TITLE  = 'menu_title';

    /**
     * Gets the callback to use to register the admin page within WordPress.
     *
     * @since 1.0.0
     *
     * @return callable Callback to hook into the respective menu action.
     */
    protected function get_register_hook_callback() {
        return function() {
            $slug        = $this->getConfigKey( self::SLUG );
            $title       = $this->getConfigKey( self::TITLE );
            $capability  = $this->getConfigKey( self::CAPABILITY );
            $parent_slug = $this->getConfigKey( self::PARENT_SLUG );
            $menu_title  = $this->hasConfigKey( self::MENU_TITLE ) ? $this->getConfigKey( self::MENU_TITLE ) : $title;

            $hook_suffix = add_submenu_page( $parent_slug, $title, $menu_title, $capability, $slug, array( $this, 'render' ) );

            add_action( "load-{$hook_suffix}", array( $this, 'initialize' ) );
        };
    }

    /**
     * Gets the parent file for the admin page URL in WordPress.
     *
     * May contain query parameters.
     *
     * @since 1.0.0
     *
     * @return string Parent file for the URL.
     */
    protected function get_parent_file() {
        $parent_slug = $this->getConfigKey( self::PARENT_SLUG );

        if ( false !== strpos( $parent_slug, '?' ) ) {
            list( $base_slug, $query ) = explode( '?', $parent_slug, 2 );
        } else {
            $base_slug = $parent_slug;
        }

        if ( '.php' === substr( $base_slug, -4 ) ) {
            return $parent_slug;
        }

        return 'admin.php';
    }

    /**
     * Gets the configuration keys that are required for an admin page.
     *
     * @since 1.0.0
     *
     * @return array Array of configuration keys.
     */
    protected function get_required_config_keys() {
        $required_keys   = parent::get_required_config_keys();
        $required_keys[] = self::PARENT_SLUG;

        return $required_keys;
    }
}