ContentFinderByRedirectUrlWithQueryStrings.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Web;
using Umbraco.Core;
using Umbraco.Core.Logging;
using Umbraco.Web.Routing;

namespace Obviuse.Utilities.Umbraco.Routing
{
    // Based on the original ContentFinderByRedirectUrl from Umbraco-Core: https://github.com/umbraco/Umbraco-CMS/blob/1bb593d264a085f94a3ce3bd710392b350561430/src/Umbraco.Web/Routing/ContentFinderByRedirectUrl.cs#L47

    /// <summary>
    /// Provides an implementation of <see cref="IContentFinder"/> that handles page url rewrites
    /// This implementation is based on the <see cref="ContentFinderByRedirectUrl" /> but is extended with support for QueryStrigs.
    /// that are stored when moving, saving, or deleting a node.
    /// </summary>
    /// <remarks>
    /// <para>Assigns a permanent redirect notification to the request.</para>
    /// </remarks>
    public class ContentFinderByRedirectUrlWithQueryStrings : IContentFinder
    {
        /// <summary>
        /// Tries to find and assign an Umbraco document to a <c>PublishedContentRequest</c>.
        /// </summary>
        /// <param name="contentRequest">The <c>PublishedContentRequest</c>.</param>
        /// <returns>A value indicating whether an Umbraco document was found and assigned.</returns>
        /// <remarks>Optionally, can also assign the template or anything else on the document request, although that is not required.</remarks>
        public bool TryFindContent(PublishedContentRequest contentRequest)
        {
            var route = contentRequest.HasDomain
                ? contentRequest.UmbracoDomain.RootContentId + DomainHelper.PathRelativeToDomain(contentRequest.DomainUri, contentRequest.Uri.GetAbsolutePathDecoded())
                : contentRequest.Uri.GetAbsolutePathDecoded();

            var service = contentRequest.RoutingContext.UmbracoContext.Application.Services.RedirectUrlService;
            var redirectUrl = service.GetMostRecentRedirectUrl(route);
            
            if (redirectUrl == null)
            {
                LogHelper.Debug<ContentFinderByRedirectUrlWithQueryStrings>("No match for route: \"{0}\".", () => route);
                return false;
            }

            var content = contentRequest.RoutingContext.UmbracoContext.ContentCache.GetById(redirectUrl.ContentId);
            var url = content == null ? "#" : content.Url;
            if (url.StartsWith("#"))
            {
                LogHelper.Debug<ContentFinderByRedirectUrlWithQueryStrings>("Route \"{0}\" matches content {1} which has no url.", () => route, () => redirectUrl.ContentId);
                return false;
            }

            LogHelper.Debug<ContentFinderByRedirectUrlWithQueryStrings>("Route \"{0}\" matches content {1} with url \"{2}\", redirecting.", () => route, () => content.Id, () => url);

            // From: http://stackoverflow.com/a/22468386/5018
            // See http://issues.umbraco.org/issue/U4-8361#comment=67-30532
            // Setting automatic 301 redirects to not be cached because browsers cache these very aggressively which then leads 
            // to problems if you rename a page back to it's original name or create a new page with the original name

            HttpContextBase cb = new HttpContextWrapper(HttpContext.Current);
            cb.Response.Cache.SetCacheability(HttpCacheability.NoCache);
            cb.Response.Cache.AppendCacheExtension("no-store, must-revalidate");
            cb.Response.AppendHeader("Pragma", "no-cache");
            cb.Response.AppendHeader("Expires", "0");

            // Can't set these values since they are internal.
            //contentRequest.Cacheability = HttpCacheability.NoCache;
            //contentRequest.CacheExtensions = new List<string> { "no-store, must-revalidate" };
            //contentRequest.Headers = new Dictionary<string, string> { { "Pragma", "no-cache" }, { "Expires", "0" } };

            // Check if the incomming request has a querystring, in that add the querystring to the redirect.
            url = string.IsNullOrEmpty(contentRequest.Uri.Query) ? url : url + contentRequest.Uri.Query;

            contentRequest.SetRedirectPermanent(url);

            return true;
        }
    }

}