From 19bfd01599e9409f6f2907a4dc941955ec8663c1 Mon Sep 17 00:00:00 2001
From: Jeff Stieler <jeff.m.stieler@gmail.com>
Date: Tue, 7 May 2019 12:42:42 -0600
Subject: [PATCH] Add new page controller class, replace page registration
 function.

---
 .../includes/class-wc-admin-loader.php        |  31 +----
 .../class-wc-admin-page-controller.php        | 120 ++++++++++++++++++
 .../page-controller-functions.php             |  17 +++
 3 files changed, 140 insertions(+), 28 deletions(-)
 create mode 100644 plugins/woocommerce-admin/includes/page-controller/class-wc-admin-page-controller.php
 create mode 100644 plugins/woocommerce-admin/includes/page-controller/page-controller-functions.php

diff --git a/plugins/woocommerce-admin/includes/class-wc-admin-loader.php b/plugins/woocommerce-admin/includes/class-wc-admin-loader.php
index d06f2e83641..beffdab10de 100644
--- a/plugins/woocommerce-admin/includes/class-wc-admin-loader.php
+++ b/plugins/woocommerce-admin/includes/class-wc-admin-loader.php
@@ -6,34 +6,6 @@
  * @package Woocommerce Admin
  */
 
-if ( ! function_exists( 'wc_admin_register_page' ) ) {
-	/**
-	 * Add a single page to a given parent top-level-item.
-	 *
-	 * @param array $options {
-	 *     Array describing the menu item.
-	 *
-	 *     @type string $title Menu title
-	 *     @type string $parent Parent path or menu ID
-	 *     @type string $path Path for this page, full path in app context; ex /analytics/report
-	 * }
-	 */
-	function wc_admin_register_page( $options ) {
-		$defaults = array(
-			'parent' => '/analytics',
-		);
-		$options  = wp_parse_args( $options, $defaults );
-		add_submenu_page(
-			'/' === $options['parent'][0] ? "wc-admin#{$options['parent']}" : $options['parent'],
-			$options['title'],
-			$options['title'],
-			'manage_options',
-			"wc-admin#{$options['path']}",
-			array( 'WC_Admin_Loader', 'page_wrapper' )
-		);
-	}
-}
-
 /**
  * WC_Admin_Loader Class.
  */
@@ -145,6 +117,9 @@ class WC_Admin_Loader {
 	 * Class loader for enabled WooCommerce Admin features/sections.
 	 */
 	public static function load_features() {
+		require_once WC_ADMIN_ABSPATH . 'includes/page-controller/class-wc-admin-page-controller.php';
+		require_once WC_ADMIN_ABSPATH . 'includes/page-controller/page-controller-functions.php';
+
 		$features = self::get_features();
 		foreach ( $features as $feature ) {
 			$feature = strtolower( $feature );
diff --git a/plugins/woocommerce-admin/includes/page-controller/class-wc-admin-page-controller.php b/plugins/woocommerce-admin/includes/page-controller/class-wc-admin-page-controller.php
new file mode 100644
index 00000000000..c8d18f172aa
--- /dev/null
+++ b/plugins/woocommerce-admin/includes/page-controller/class-wc-admin-page-controller.php
@@ -0,0 +1,120 @@
+<?php
+/**
+ * WC_Admin_Page_Controller
+ *
+ * @package Woocommerce Admin
+ */
+
+/**
+ * WC_Admin_Page_Controller
+ */
+class WC_Admin_Page_Controller {
+	// JS-powered page root.
+	const PAGE_ROOT = 'wc-admin#';
+
+	/**
+	 * Singleton instance of self.
+	 *
+	 * @var WC_Admin_Page_Controller
+	 */
+	private static $instance = false;
+
+	/**
+	 * Registered pages
+	 * Contains information (breadcrumbs, menu info) about JS powered pages and classic WooCommerce pages.
+	 *
+	 * @var array
+	 */
+	private $pages = array();
+
+	/**
+	 * We want a single instance of this class so we can accurately track registered menus and pages.
+	 */
+	public static function get_instance() {
+		if ( ! self::$instance ) {
+			self::$instance = new self();
+		}
+
+		return self::$instance;
+	}
+
+	/**
+	 * Returns the path from an ID.
+	 *
+	 * @param  string $id  ID to get path for.
+	 * @return string|null Path for the given ID.
+	 */
+	public function get_path_from_id( $id ) {
+		if ( isset( $this->pages[ $id ] ) && isset( $this->pages[ $id ]['path'] ) ) {
+			return $this->pages[ $id ]['path'];
+		}
+		return null;
+	}
+
+	/**
+	 * Adds a JS powered page to wc-admin.
+	 *
+	 * @param array $options {
+	 *   Array describing the page.
+	 *
+	 *   @type string      id           Id to reference the page.
+	 *   @type string      title        Page title. Used in menus and breadcrumbs.
+	 *   @type string|null parent       Parent ID. Null for new top level page.
+	 *   @type string      path         Path for this page, full path in app context; ex /analytics/report
+	 *   @type string      capability   Capability needed to access the page.
+	 *   @type string      icon         Icon. Dashicons helper class, base64-encoded SVG, or 'none'.
+	 *   @type int         position     Menu item position.
+	 * }
+	 */
+	public function register_page( $options ) {
+		$defaults = array(
+			'id'         => null,
+			'parent'     => null,
+			'title'      => '',
+			'capability' => 'manage_options',
+			'path'       => '',
+			'icon'       => '',
+			'position'   => null,
+		);
+
+		$options         = wp_parse_args( $options, $defaults );
+		$options['path'] = self::PAGE_ROOT . $options['path'];
+
+		// TODO: check for null ID, or collision.
+		$this->pages[ $options['id'] ] = $options;
+
+		if ( is_null( $options['parent'] ) ) {
+			add_menu_page(
+				$options['title'],
+				$options['title'],
+				$options['capability'],
+				$options['path'],
+				array( __CLASS__, 'page_wrapper' ),
+				$options['icon'],
+				$options['position']
+			);
+		} else {
+			$parent_path = $this->get_path_from_id( $options['parent'] );
+			// TODO: check for null path.
+			add_submenu_page(
+				$parent_path,
+				$options['title'],
+				$options['title'],
+				$options['capability'],
+				$options['path'],
+				array( __CLASS__, 'page_wrapper' )
+			);
+		}
+	}
+
+	/**
+	 * Set up a div for the app to render into.
+	 */
+	public static function page_wrapper() {
+		?>
+		<div class="wrap">
+			<div id="root"></div>
+		</div>
+		<?php
+	}
+}
diff --git a/plugins/woocommerce-admin/includes/page-controller/page-controller-functions.php b/plugins/woocommerce-admin/includes/page-controller/page-controller-functions.php
new file mode 100644
index 00000000000..37c7eb141dd
--- /dev/null
+++ b/plugins/woocommerce-admin/includes/page-controller/page-controller-functions.php
@@ -0,0 +1,17 @@
+<?php
+/**
+ * Convenience functions for WC_Admin_Page_Controller.
+ *
+ * @package Woocommerce Admin
+ */
+
+/**
+ * Register JS-powered WooCommerce Admin Page.
+ * Passthrough to WC_Admin_Page_Controller::register_page().
+ *
+ * @param array $options Options for WC_Admin_Page_Controller::register_page().
+ */
+function wc_admin_register_page( $options ) {
+	$controller = WC_Admin_Page_Controller::get_instance();
+	$controller->register_page( $options );
+}