From 7c49bb4acadcaea1986c332e7d7a0be6eecbbfc1 Mon Sep 17 00:00:00 2001
From: Marc Goodson <marc@snowmoon.co.uk>
Date: Sun, 12 Jun 2016 16:54:13 +0100
Subject: [PATCH] Event Handler to wire up to publishing and moving events to
 track Url changes, and then create appropriate 301 redirects using the new
 RedirectUrlService to maintain google juice

---
 .../Redirects/RedirectTrackingEventHandler.cs | 123 ++++++++++++++++++
 src/Umbraco.Web/Umbraco.Web.csproj            |   1 +
 2 files changed, 124 insertions(+)
 create mode 100644 src/Umbraco.Web/Redirects/RedirectTrackingEventHandler.cs

diff --git a/src/Umbraco.Web/Redirects/RedirectTrackingEventHandler.cs b/src/Umbraco.Web/Redirects/RedirectTrackingEventHandler.cs
new file mode 100644
index 0000000000..6bc5259850
--- /dev/null
+++ b/src/Umbraco.Web/Redirects/RedirectTrackingEventHandler.cs
@@ -0,0 +1,123 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Umbraco.Core;
+using Umbraco.Core.Models;
+using Umbraco.Core.Services;
+using Umbraco.Core.Strings;
+
+namespace Umbraco.Web.Redirects
+{
+    //when content is renamed or moved, we want to create a permanent 301 redirect from it's old url
+    public class RedirectTrackingEventHandler : ApplicationEventHandler
+    {
+        protected override void ApplicationStarting
+              (UmbracoApplicationBase umbracoApplication,
+               ApplicationContext applicationContext)
+        {
+            //create a redirect if the item is published
+            // on the publishing event the previous Url won't have been updated in the cache yet
+            ContentService.Publishing += ContentService_Publishing;
+
+            // create a redirect if the item is being moved
+            ContentService.Moving += ContentService_Moving;
+
+            //rolled back items have to be published, so publishing will take care of that
+
+            // do we want to do anything if a content item is unpublished or deleted ?
+            // eg. remove any redirects to the node or associated redirects created by previous nodes
+            // for now it will just 404 which is correct I think
+        }
+        private void ContentService_Publishing(Core.Publishing.IPublishingStrategy sender, Core.Events.PublishEventArgs<IContent> e)
+        {
+            foreach (var publishedEntity in e.PublishedEntities)
+            {
+                CreateRedirectsIfUrlHasChanged(publishedEntity);
+            }
+        }
+        private void ContentService_Moving(IContentService sender, Core.Events.MoveEventArgs<IContent> e)
+        {
+            var umbracoHelper = new Umbraco.Web.UmbracoHelper(Umbraco.Web.UmbracoContext.Current);
+            var redirectUrlService = ApplicationContext.Current.Services.RedirectUrlService;
+
+            foreach (var moveEventInfo in e.MoveInfoCollection)
+            {
+                var entityBeingMoved = moveEventInfo.Entity;
+                //entity hasn't moved yet so current Url is ?
+                var currentUrl = umbracoHelper.Url(moveEventInfo.Entity.Id);
+                if (!String.IsNullOrWhiteSpace(currentUrl) && currentUrl != "/")
+                {
+                    //create redirectUrl
+                    var redirectUrl = new RedirectUrl()
+                    {
+                        ContentId = entityBeingMoved.Id,
+                        Url = currentUrl,
+                        CreateDateUtc = DateTime.UtcNow
+                    };
+                    redirectUrlService.Save(redirectUrl);
+
+                    // has the moved item got descendants ?
+                    CreateRedirectsForDescendants(entityBeingMoved);
+                }
+
+                // thoughts
+                // is the entity being moved from the recycle bin ?
+            }
+        }
+        private void CreateRedirectsIfUrlHasChanged(IContent entity)
+        {
+            var umbracoHelper = new Umbraco.Web.UmbracoHelper(Umbraco.Web.UmbracoContext.Current);
+            var redirectUrlService = ApplicationContext.Current.Services.RedirectUrlService;
+            //url won't have changed in the cache yet
+            var currentUrl = umbracoHelper.UrlAbsolute(entity.Id);
+            if (!String.IsNullOrWhiteSpace(currentUrl))
+            {
+                //get last segment of current url    
+                var currentUri = new Uri(currentUrl);
+                var currentLastSegment = (currentUri != null && currentUri.Segments.Any()) ? currentUri.Segments.LastOrDefault().Replace("/", "") : String.Empty;
+                // get segment of update entity
+                var updatedUrlSegment = entity.GetUrlSegment();
+                if (!String.IsNullOrWhiteSpace(currentLastSegment) && !currentLastSegment.InvariantEquals(updatedUrlSegment))
+                {
+                    //url has changed...
+                    //create redirectUrl
+                    var redirectUrl = new RedirectUrl()
+                    {
+                        ContentId = entity.Id,
+                        Url = currentUrl,
+                        CreateDateUtc = DateTime.UtcNow
+                    };
+                    //create redirect for any descendants
+                    CreateRedirectsForDescendants(entity);
+                }
+            }
+        }
+        private void CreateRedirectsForDescendants(IContent entity)
+        {
+            var umbracoHelper = new Umbraco.Web.UmbracoHelper(Umbraco.Web.UmbracoContext.Current);
+            var redirectUrlService = ApplicationContext.Current.Services.RedirectUrlService;
+            var descendants = entity.Descendants();
+            if (descendants.Any())
+            {
+                foreach (var descendant in descendants)
+                {
+                    // create redirect url for each descendant item
+                    var currentUrl = umbracoHelper.Url(descendant.Id);
+                    if (!String.IsNullOrWhiteSpace(currentUrl))
+                    {
+                        //create redirectUrl
+                        var redirectUrl = new RedirectUrl()
+                        {
+                            ContentId = descendant.Id,
+                            Url = currentUrl,
+                            CreateDateUtc = DateTime.UtcNow
+                        };
+
+                    }
+                }
+            }
+        }
+    }
+}
diff --git a/src/Umbraco.Web/Umbraco.Web.csproj b/src/Umbraco.Web/Umbraco.Web.csproj
index 3ca753db63..18a4ded950 100644
--- a/src/Umbraco.Web/Umbraco.Web.csproj
+++ b/src/Umbraco.Web/Umbraco.Web.csproj
@@ -358,6 +358,7 @@
     <Compile Include="PropertyEditors\DecimalPropertyEditor.cs" />
     <Compile Include="PropertyEditors\ValueConverters\ImageCropDataSetConverter.cs" />
     <Compile Include="PropertyEditors\ValueConverters\ImageCropperValueConverter.cs" />
+    <Compile Include="Redirects\RedirectTrackingEventHandler.cs" />
     <Compile Include="RequestLifespanMessagesFactory.cs" />
     <Compile Include="RouteDataExtensions.cs" />
     <Compile Include="Routing\ContentFinderByRedirectUrl.cs" />