Adding rss endpoint for tagged content items

src/Orchard.Web/Core/Feeds/StandardQueries/ContainerFeedQuery.cs

@@ -44,8 +44,11 @@ namespace Orchard.Core.Feeds.StandardQueries {
 
             var limitValue = context.ValueProvider.GetValue("limit");
             var limit = 20;
-            if (limitValue != null)
-                limit = (int)limitValue.ConvertTo(typeof(int));
+            if (limitValue != null) {
+                Int32.TryParse(Convert.ToString(limitValue), out limit);
+            }
+            
+            limit = Math.Min(limit, 100);
 
             var containerId = (int)containerIdValue.ConvertTo(typeof(int));
             var container = _contentManager.Get(containerId);

src/Orchard.Web/Modules/Orchard.Comments/Feeds/CommentedOnContainerFeedQuery.cs

@@ -30,6 +30,8 @@ namespace Orchard.Comments.Feeds {
                 Int32.TryParse(Convert.ToString(limitValue), out limit);
             }
 
+            limit = Math.Min(limit, 100);
+
             var comments = _contentManager
                 .Query<CommentPart, CommentPartRecord>()
                 .Where(x => x.CommentedOnContainer == commentedOnContainer && x.Status == CommentStatus.Approved)

src/Orchard.Web/Modules/Orchard.Tags/Feeds/TagFeedQuery.cs

@@ -0,0 +1,109 @@
+using System;
+using System.Collections.Generic;
+using System.Web.Mvc;
+using System.Xml.Linq;
+using JetBrains.Annotations;
+using Orchard.ContentManagement;
+using Orchard.Core.Common.Models;
+using Orchard.Core.Feeds.Models;
+using Orchard.Core.Feeds.StandardBuilders;
+using Orchard.Mvc.Extensions;
+using Orchard.Services;
+using Orchard.Utility.Extensions;
+using Orchard.Core.Feeds;
+using Orchard.Tags.Services;
+using Orchard.Localization;
+using System.Web.Routing;
+using Orchard.Environment.Extensions;
+
+namespace Orchard.Tags.Feeds {
+    [OrchardFeature("Orchard.Tags.Feeds")]
+    public class TagFeedQuery : IFeedQueryProvider, IFeedQuery {
+        private readonly IContentManager _contentManager;
+        private readonly IEnumerable<IHtmlFilter> _htmlFilters;
+        private readonly ITagService _tagService;
+
+        public TagFeedQuery(
+            IContentManager contentManager, 
+            IEnumerable<IHtmlFilter> htmlFilters,
+            ITagService tagService) {
+            _contentManager = contentManager;
+            _tagService = tagService;
+            _htmlFilters = htmlFilters;
+
+            T = NullLocalizer.Instance;
+        }
+
+        public Localizer T { get; set; }
+
+        public FeedQueryMatch Match(FeedContext context) {
+            var tagIdValue = context.ValueProvider.GetValue("tag");
+            if (tagIdValue == null)
+                return null;
+
+            var tagName = (string)tagIdValue.ConvertTo(typeof(string));
+            var tag = _tagService.GetTagByName(tagName);
+            
+            if (tag == null) {
+                return null;
+            }
+            
+            return new FeedQueryMatch { FeedQuery = this, Priority = -5 };
+        }
+
+        public void Execute(FeedContext context) {
+            var tagIdValue = context.ValueProvider.GetValue("tag");
+            if (tagIdValue == null)
+                return;
+
+            var limitValue = context.ValueProvider.GetValue("limit");
+            var limit = 20;
+            if (limitValue != null) { 
+                Int32.TryParse(Convert.ToString(limitValue), out limit);
+            }
+            
+            limit = Math.Min(limit, 100);
+
+            var tagName = (string)tagIdValue.ConvertTo(typeof(string));
+            var tag = _tagService.GetTagByName(tagName);
+
+            if (tag == null) {
+                return;
+            }
+
+            var displayRouteValues = new RouteValueDictionary {
+                {"area", "Orchard.Tags"},
+                {"controller", "Home"},
+                {"action", "Search"},
+                {"tagName", tag.TagName}
+            };
+
+            if (context.Format == "rss") {
+                var link = new XElement("link");
+                context.Response.Element.SetElementValue("title", tag.TagName);
+                context.Response.Element.Add(link);
+                context.Response.Element.SetElementValue("description", T("Content tagged with {0}", tag.TagName).ToString());
+
+                context.Response.Contextualize(requestContext => {
+                    var urlHelper = new UrlHelper(requestContext);
+                    var uriBuilder = new UriBuilder(urlHelper.MakeAbsolute("/")) { Path = urlHelper.RouteUrl(displayRouteValues) };
+                    link.Add(uriBuilder.Uri.OriginalString);
+                });
+            }
+            else {
+                context.Builder.AddProperty(context, null, "title", tag.TagName);
+                context.Builder.AddProperty(context, null, "description", T("Content tagged with {0}", tag.TagName).ToString());
+                context.Response.Contextualize(requestContext => {
+                    var urlHelper = new UrlHelper(requestContext);
+                    context.Builder.AddProperty(context, null, "link", urlHelper.MakeAbsolute(urlHelper.RouteUrl(displayRouteValues)));
+                });
+            }
+
+            var items = _tagService.GetTaggedContentItems(tag.Id, 0, limit);
+
+            foreach (var item in items) {
+                context.Builder.AddItem(context, item.ContentItem);
+            }
+        }
+    }
+}

src/Orchard.Web/Modules/Orchard.Tags/Orchard.Tags.csproj

@@ -68,6 +68,7 @@
     <Compile Include="AdminMenu.cs" />
     <Compile Include="Controllers\AdminController.cs" />
     <Compile Include="Drivers\TagCloudDriver.cs" />
+    <Compile Include="Feeds\TagFeedQuery.cs" />
     <Compile Include="Feeds\TagsFeedItemBuilder.cs" />
     <Compile Include="Handlers\TagCloudHandler.cs" />
     <Compile Include="Migrations.cs" />