From b225075d021271bdd99639d4f987809041e5622c Mon Sep 17 00:00:00 2001
From: Anton Kachurin <kachurinanton@gmail.com>
Date: Thu, 25 Oct 2018 16:34:52 -0400
Subject: [PATCH 1/9] Add class that allows to calculate changes in post
 hierarchy

---
 includes/class-tree-view.php | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/includes/class-tree-view.php b/includes/class-tree-view.php
index eedf577..9acee49 100644
--- a/includes/class-tree-view.php
+++ b/includes/class-tree-view.php
@@ -316,6 +316,37 @@ public function add_node_prefix( $id ) {
 
 }
 
+class BU_Navigation_Tree_Hierarchy {
+
+	const HIERARCHICAL_PROPERTIES = array( 'ID', 'excluded', 'menu_order', 'post_parent' );
+	public $query;
+
+	public function __construct( $query ) {
+		$this->query = $query;
+	}
+
+	public function as_object() {
+		$hierarchy = $this->query->posts_by_parent();
+		foreach ( $hierarchy as $parent ) {
+			foreach ( $parent as $child ) {
+				foreach ( $child as $prop_name => $prop_value ) {
+					if ( ! in_array( $prop_name, self::HIERARCHICAL_PROPERTIES ) ) {
+						unset( $child->$prop_name );
+					}
+				}
+			}
+		}
+
+		return $hierarchy;
+	}
+
+	public function as_hash() {
+		$obj = $this->as_object();
+		$str = json_encode( $obj );
+		return md5( $str );
+	}
+}
+
 /**
  * WP_Query-like class optimized for querying hierarchical post types
  *

From e1b5a958865cb822a177e14495cac0ca3f7a2f95 Mon Sep 17 00:00:00 2001
From: Anton Kachurin <kachurinanton@gmail.com>
Date: Thu, 25 Oct 2018 16:40:27 -0400
Subject: [PATCH 2/9] Refactor instantiation of BU_Navigation_Tree_View into
 separate method

---
 admin/manager.php | 68 ++++++++++++++++++++++++++---------------------
 1 file changed, 38 insertions(+), 30 deletions(-)

diff --git a/admin/manager.php b/admin/manager.php
index b1ab7df..04d26a8 100644
--- a/admin/manager.php
+++ b/admin/manager.php
@@ -126,37 +126,8 @@ public function add_scripts( $page ) {
 			wp_register_script( 'bu-jquery-validate', $vendor_url . '/jquery.validate' . $suffix . '.js', array( 'jquery' ), '1.8.1', true );
 			wp_register_script( 'bu-navman', $scripts_url . '/manage' . $suffix . '.js', array( 'bu-navigation', 'jquery-ui-dialog', 'bu-jquery-validate' ), BU_Navigation_Plugin::VERSION, true );
 
-			// Strings for localization
-			$nav_menu_label = __( 'Appearance > Primary Navigation', 'bu-navigation' );
-			$strings = array(
-				'optionsLabel' => __( 'options', 'bu-navigation' ),
-				'optionsEditLabel' => __( 'Edit', 'bu-navigation' ),
-				'optionsViewLabel' => __( 'View', 'bu-navigation' ),
-				'optionsDeleteLabel' => __( 'Delete', 'bu-navigation' ),
-				'optionsTrashLabel' => __( 'Move to Trash', 'bu-navigation' ),
-				'addLinkDialogTitle' => __( 'Add a Link', 'bu-navigation' ),
-				'editLinkDialogTitle' => __( 'Edit Link', 'bu-navigation' ),
-				'cancelLinkBtn' => __( 'Cancel', 'bu-navigation' ),
-				'confirmLinkBtn' => __( 'Ok', 'bu-navigation' ),
-				'noTopLevelNotice' => __( 'You are not allowed to create top level published content.', 'bu-navigation' ),
-				'noLinksNotice' => __( 'You are not allowed to add links', 'bu-navigation' ),
-				'createLinkNotice' => __( 'Select a page that you can edit and click "Add a Link" to create a new link below the selected page.', 'bu-navigation' ),
-				'allowTopNotice' => sprintf( __( 'Site administrators can change this behavior by visiting %s and enabling the "Allow Top-Level Pages" setting.', 'bu-navigation' ), $nav_menu_label ),
-				'noChildLinkNotice' => __( 'Links are not permitted to have children.', 'bu-navigation' ),
-				'unloadWarning' => __( 'You have made changes to your navigation that have not yet been saved.', 'bu-navigation' ),
-				'saveNotice' => __( 'Saving navigation changes...', 'bu-navigation' ),
-				);
-
-			// Setup dynamic script context for manage.js
-			$script_context = array(
-				'postTypes' => $this->post_type,
-				'postStatuses' => array( 'publish', 'private' ),
-				'nodePrefix' => 'nm',
-				'lazyLoad' => true,
-				'showCounts' => true,
-				);
 			// Navigation tree view will handle actual enqueuing of our script
-			$treeview = new BU_Navigation_Tree_View( 'bu_navman', array_merge( $script_context, $strings ) );
+			$treeview = $this->get_navigation_tree();
 			$treeview->enqueue_script( 'bu-navman' );
 
 			// Register custom jQuery UI stylesheet if it isn't already
@@ -174,6 +145,43 @@ public function add_scripts( $page ) {
 
 	}
 
+	/**
+	 * Get fully configured instance of BU_Navigation_Tree_View
+	 */
+	public function get_navigation_tree() {
+		// Strings for localization
+		$nav_menu_label = __( 'Appearance > Primary Navigation', 'bu-navigation' );
+		$strings = array(
+			'optionsLabel' => __( 'options', 'bu-navigation' ),
+			'optionsEditLabel' => __( 'Edit', 'bu-navigation' ),
+			'optionsViewLabel' => __( 'View', 'bu-navigation' ),
+			'optionsDeleteLabel' => __( 'Delete', 'bu-navigation' ),
+			'optionsTrashLabel' => __( 'Move to Trash', 'bu-navigation' ),
+			'addLinkDialogTitle' => __( 'Add a Link', 'bu-navigation' ),
+			'editLinkDialogTitle' => __( 'Edit Link', 'bu-navigation' ),
+			'cancelLinkBtn' => __( 'Cancel', 'bu-navigation' ),
+			'confirmLinkBtn' => __( 'Ok', 'bu-navigation' ),
+			'noTopLevelNotice' => __( 'You are not allowed to create top level published content.', 'bu-navigation' ),
+			'noLinksNotice' => __( 'You are not allowed to add links', 'bu-navigation' ),
+			'createLinkNotice' => __( 'Select a page that you can edit and click "Add a Link" to create a new link below the selected page.', 'bu-navigation' ),
+			'allowTopNotice' => sprintf( __( 'Site administrators can change this behavior by visiting %s and enabling the "Allow Top-Level Pages" setting.', 'bu-navigation' ), $nav_menu_label ),
+			'noChildLinkNotice' => __( 'Links are not permitted to have children.', 'bu-navigation' ),
+			'unloadWarning' => __( 'You have made changes to your navigation that have not yet been saved.', 'bu-navigation' ),
+			'saveNotice' => __( 'Saving navigation changes...', 'bu-navigation' ),
+		);
+
+		// Setup dynamic script context for manage.js
+		$script_context = array(
+			'postTypes' => $this->post_type,
+			'postStatuses' => array( 'publish', 'private' ),
+			'nodePrefix' => 'nm',
+			'lazyLoad' => true,
+			'showCounts' => true,
+		);
+
+		return new BU_Navigation_Tree_View( 'bu_navman', array_merge( $script_context, $strings ) );
+	}
+
 	/**
 	 * Handle admin page setup
 	 */

From 4d55b062a56bbdfdc21629141dc950b55088dd6f Mon Sep 17 00:00:00 2001
From: Anton Kachurin <kachurinanton@gmail.com>
Date: Thu, 25 Oct 2018 16:43:23 -0400
Subject: [PATCH 3/9] Submit original page hierarchy hash when saving page
 order

---
 admin/manager.php            | 2 +-
 includes/class-tree-view.php | 3 +++
 templates/edit-order.php     | 1 +
 3 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/admin/manager.php b/admin/manager.php
index 04d26a8..8c9fdbe 100644
--- a/admin/manager.php
+++ b/admin/manager.php
@@ -329,7 +329,7 @@ public function render() {
 		$notices = $this->get_notice_list();
 		$include_links = $this->plugin->supports( 'links' ) && 'page' == $this->post_type;
 		$disable_add_link = ! $this->can_publish_top_level( $this->post_type );
-
+		$tree = $this->get_navigation_tree();
 		// Render interface
 		include( BU_NAV_PLUGIN_DIR . '/templates/edit-order.php' );
 
diff --git a/includes/class-tree-view.php b/includes/class-tree-view.php
index 9acee49..3f2a431 100644
--- a/includes/class-tree-view.php
+++ b/includes/class-tree-view.php
@@ -12,6 +12,8 @@ class BU_Navigation_Tree_View {
 	private $plugin;
 
 	private $query;
+	
+	public $hierarchy;
 
 	/**
 	 * Setup an object capable of creating the navigation management interface
@@ -60,6 +62,7 @@ public function __construct( $instance = 'legacy', $script_context = array() ) {
 			'suppress_urls' => $this->settings['suppressUrls']
 		);
 		$this->query = new BU_Navigation_Tree_Query( $query_args );
+		$this->hierarchy = new BU_Navigation_Tree_Hierarchy( $this->query );
 
 		// No need to register scripts during AJAX requests
 		if( ! defined('DOING_AJAX') || ! DOING_AJAX ) {
diff --git a/templates/edit-order.php b/templates/edit-order.php
index 0652559..b87cede 100644
--- a/templates/edit-order.php
+++ b/templates/edit-order.php
@@ -5,6 +5,7 @@
 
 	<div id="navman-container">
 		<form method="post" id="navman_form" action="">
+			<input type="hidden" id="navman-hash" name="navman-hash" value="<?php echo esc_attr( $tree->hierarchy->as_hash() ); ?>" />
 			<input type="hidden" id="navman-moves" name="navman-moves" value="" />
 			<input type="hidden" id="navman-inserts" name="navman-inserts" value="" />
 			<input type="hidden" id="navman-updates" name="navman-updates" value="" />

From 86a937337ca9e0931de79284a3a7d07cdcae8ff0 Mon Sep 17 00:00:00 2001
From: Anton Kachurin <kachurinanton@gmail.com>
Date: Thu, 25 Oct 2018 16:45:57 -0400
Subject: [PATCH 4/9] Show error if page hierarchy hash changed before new
 changes submitted

---
 admin/manager.php | 34 ++++++++++++++++++++++++++--------
 1 file changed, 26 insertions(+), 8 deletions(-)

diff --git a/admin/manager.php b/admin/manager.php
index 8c9fdbe..52a20a1 100644
--- a/admin/manager.php
+++ b/admin/manager.php
@@ -145,9 +145,6 @@ public function add_scripts( $page ) {
 
 	}
 
-	/**
-	 * Get fully configured instance of BU_Navigation_Tree_View
-	 */
 	public function get_navigation_tree() {
 		// Strings for localization
 		$nav_menu_label = __( 'Appearance > Primary Navigation', 'bu-navigation' );
@@ -178,7 +175,7 @@ public function get_navigation_tree() {
 			'lazyLoad' => true,
 			'showCounts' => true,
 		);
-
+		
 		return new BU_Navigation_Tree_View( 'bu_navman', array_merge( $script_context, $strings ) );
 	}
 
@@ -187,8 +184,20 @@ public function get_navigation_tree() {
 	 */
 	public function load() {
 
-		// Save if post data is present
-		$saved = $this->save();
+		if ( array_key_exists( 'navman-hash', $_POST ) ) {
+			$tree = $this->get_navigation_tree();
+			$hash_stayed_same = $tree->hierarchy->as_hash() == $_POST['navman-hash'];
+		}
+		else {
+			$hash_stayed_same = true;
+		}
+
+		if ( $hash_stayed_same ) {
+			$saved = $this->save();
+		}
+		else {
+			$saved = false;
+		}
 
 		// Post/Redirect/Get
 		if ( ! is_null( $saved ) ) {
@@ -197,8 +206,16 @@ public function load() {
 			$url = remove_query_arg( array( 'message', 'notice' ), wp_get_referer() );
 
 			// Notifications
-			if ( $saved === true ) { $url = add_query_arg( 'message', 1, $url );
-			} else { $url = add_query_arg( 'notice', 1, $url ); }
+			if ( $saved === true ) {
+				$url = add_query_arg( 'message', 1, $url );
+			} else {
+				if ( ! $hash_stayed_same ) {
+					$url = add_query_arg( 'notice', 3, $url );
+				}
+				else {
+					$url = add_query_arg( 'notice', 1, $url ); 
+				}
+			}
 
 			wp_redirect( $url );
 
@@ -250,6 +267,7 @@ public function get_notice_by_code( $type, $code ) {
 				0 => '',
 				1 => __( 'Errors occurred while saving your navigation changes.', 'bu-navigation' ),
 				2 => sprintf( __( "Warning: %s is currently editing this site's navigation.", 'bu-navigation' ), $user_markup ),
+				3 => __( "Error: Another user made changes to this site's navigation menu. Please retry.", 'bu-navigation' ),
 			),
 		);
 

From ce24ff5f52804e9b658e0c9f5d1c91fced6a60a6 Mon Sep 17 00:00:00 2001
From: Anton Kachurin <kachurinanton@gmail.com>
Date: Thu, 25 Oct 2018 16:58:44 -0400
Subject: [PATCH 5/9] Add docs to method

---
 admin/manager.php | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/admin/manager.php b/admin/manager.php
index 52a20a1..106babe 100644
--- a/admin/manager.php
+++ b/admin/manager.php
@@ -145,6 +145,9 @@ public function add_scripts( $page ) {
 
 	}
 
+	/**	
+	 * Get fully configured instance of BU_Navigation_Tree_View	
+	 */
 	public function get_navigation_tree() {
 		// Strings for localization
 		$nav_menu_label = __( 'Appearance > Primary Navigation', 'bu-navigation' );
@@ -175,7 +178,7 @@ public function get_navigation_tree() {
 			'lazyLoad' => true,
 			'showCounts' => true,
 		);
-		
+
 		return new BU_Navigation_Tree_View( 'bu_navman', array_merge( $script_context, $strings ) );
 	}
 

From c6804b7fd3c67c89892bbbadd3bacd5c74991bc5 Mon Sep 17 00:00:00 2001
From: Anton Kachurin <kachurinanton@gmail.com>
Date: Thu, 25 Oct 2018 17:14:16 -0400
Subject: [PATCH 6/9] Exclude php 5.4 and 5.5 from testing

---
 .travis.yml | 2 --
 1 file changed, 2 deletions(-)

diff --git a/.travis.yml b/.travis.yml
index 991cdc9..f3c856a 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -3,8 +3,6 @@ language: php
 sudo: false
 
 php:
-    - 5.4
-    - 5.5
     - 5.6
     - 7.0
     - 7.1

From 90ffdbb2d647ad3a8c54ec887cfebab93554991b Mon Sep 17 00:00:00 2001
From: Anton Kachurin <kachurinanton@gmail.com>
Date: Mon, 26 Nov 2018 16:56:18 -0500
Subject: [PATCH 7/9] Refactor and document hierarchy class

---
 includes/class-tree-view.php | 43 ++++++++++++++++++++++++++++++------
 1 file changed, 36 insertions(+), 7 deletions(-)

diff --git a/includes/class-tree-view.php b/includes/class-tree-view.php
index 3f2a431..6e77194 100644
--- a/includes/class-tree-view.php
+++ b/includes/class-tree-view.php
@@ -319,17 +319,33 @@ public function add_node_prefix( $id ) {
 
 }
 
+/**
+ * Collection of methods that allow the page hierarchy be represented as 
+ * a hash value. By comparing two hash values, we can tell if there were
+ * any changes in the hierarchy.
+ */
 class BU_Navigation_Tree_Hierarchy {
 
-	const HIERARCHICAL_PROPERTIES = array( 'ID', 'excluded', 'menu_order', 'post_parent' );
-	public $query;
+	/**
+	 * Holds the BU_Navigation_Tree_Query instance passed into constructor.
+	 */
+	private $tree_query;
 
-	public function __construct( $query ) {
-		$this->query = $query;
-	}
+	/**
+	 * Post properties that describe hierarchy. If any of these changed,
+	 * the hierarchy changed.
+	 */
+	const HIERARCHICAL_PROPERTIES = array( 'ID', 'menu_order', 'post_parent' );
 
-	public function as_object() {
-		$hierarchy = $this->query->posts_by_parent();
+	/**
+	 * By taking the posts structure and leaving only hierarchy-related
+	 * preperties of it, we get the object that stays the same as long as
+	 * the post hierarchy stays the same.
+	 * 
+	 * @return array Object that represents post tree hierarchy
+	 */
+	private function as_object() {
+		$hierarchy = $this->tree_query->posts_by_parent();
 		foreach ( $hierarchy as $parent ) {
 			foreach ( $parent as $child ) {
 				foreach ( $child as $prop_name => $prop_value ) {
@@ -343,6 +359,19 @@ public function as_object() {
 		return $hierarchy;
 	}
 
+	/**
+	 * Constructor.
+	 */
+	public function __construct( BU_Navigation_Tree_Query $tree_query ) {
+		$this->tree_query = $tree_query;
+	}
+
+	/**
+	 * Gets hashed representation of the BU_Navigation_Tree_Query instance
+	 * passed into the constructor of this class.
+	 * 
+	 * @return String hashed representation of the post hierarchy
+	 */
 	public function as_hash() {
 		$obj = $this->as_object();
 		$str = json_encode( $obj );

From d885b3e354ff79f450d6918076d7933f46527c6a Mon Sep 17 00:00:00 2001
From: Anton Kachurin <kachurinanton@gmail.com>
Date: Mon, 26 Nov 2018 18:03:25 -0500
Subject: [PATCH 8/9] Improve notice language

---
 admin/manager.php | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/admin/manager.php b/admin/manager.php
index 106babe..a86db1f 100644
--- a/admin/manager.php
+++ b/admin/manager.php
@@ -260,6 +260,7 @@ public function setup_notices() {
 	public function get_notice_by_code( $type, $code ) {
 
 		$user_markup = '<strong>%s</strong>';
+		$post_type = get_post_type_object( $this->post_type );
 
 		$notices = array(
 			'message' => array(
@@ -270,7 +271,7 @@ public function get_notice_by_code( $type, $code ) {
 				0 => '',
 				1 => __( 'Errors occurred while saving your navigation changes.', 'bu-navigation' ),
 				2 => sprintf( __( "Warning: %s is currently editing this site's navigation.", 'bu-navigation' ), $user_markup ),
-				3 => __( "Error: Another user made changes to this site's navigation menu. Please retry.", 'bu-navigation' ),
+				3 => sprintf( __( '%s order has been modified by someone else. Please retry.', 'bu-navigation' ),  $post_type->labels->singular_name),
 			),
 		);
 

From bf41a61e053f5fe6c53872dff117ea8630f7ac09 Mon Sep 17 00:00:00 2001
From: Anton Kachurin <kachurinanton@gmail.com>
Date: Thu, 6 Dec 2018 12:24:32 -0500
Subject: [PATCH 9/9] Release 1.2.14

---
 bu-navigation.php | 4 ++--
 readme.md         | 5 ++++-
 readme.txt        | 7 ++++++-
 3 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/bu-navigation.php b/bu-navigation.php
index e61dab0..930e1cc 100644
--- a/bu-navigation.php
+++ b/bu-navigation.php
@@ -5,7 +5,7 @@
 Author: Boston University (IS&T)
 Author URI: http://sites.bu.edu/web/
 Description: Provides alternative navigation elements designed for blogs with large page counts
-Version: 1.2.13
+Version: 1.2.14
 Text Domain: bu-navigation
 Domain Path: /languages
 */
@@ -60,7 +60,7 @@ class BU_Navigation_Plugin {
 	// Plugin settings
 	public $settings;
 
-	const VERSION = '1.2.13';
+	const VERSION = '1.2.14';
 
 	public function __construct() {
 
diff --git a/readme.md b/readme.md
index 96dc004..e3b72e2 100644
--- a/readme.md
+++ b/readme.md
@@ -3,7 +3,7 @@
 **Tags:** navigation, hierarchical, post type, boston university, bu  
 **Requires at least:** 3.1  
 **Tested up to:** 4.6.1  
-**Stable tag:** 1.2.13  
+**Stable tag:** 1.2.14  
 **License:** GPLv2 or later  
 **License URI:** http://www.gnu.org/licenses/gpl-2.0.html  
 
@@ -99,6 +99,9 @@ Please see this page for the details:
 
 ## Changelog 
 
+### 1.2.14
+
+* Add hash comparison before saving changes to post hierarchy in Change Order page.
 
 ### 1.2.13 
 
diff --git a/readme.txt b/readme.txt
index cee6888..10a95ba 100644
--- a/readme.txt
+++ b/readme.txt
@@ -3,7 +3,7 @@ Contributors: ntk, mgburns, gcorne, jtwiest, awbauer, inderpreet99
 Tags: navigation, hierarchical, post type, boston university, bu
 Requires at least: 3.1
 Tested up to: 4.6.1
-Stable tag: 1.2.13
+Stable tag: 1.2.14
 License: GPLv2 or later
 License URI: http://www.gnu.org/licenses/gpl-2.0.html
 
@@ -78,6 +78,11 @@ Please see this page for the details:
 
 == Changelog ==
 
+= 1.2.14 =
+
+* Add hash comparison before saving changes to post hierarchy in Change Order page.
+
+
 = 1.2.13 =
 
 * Add missing parameter to `the_title` filter call. Part 2.