items-feed support (#28)

Related to issue #20

Kontent.Statiq.Tests/Tools/KontentSetupHelpers.cs

@@ -1,6 +1,7 @@
 using FakeItEasy;
 using Kentico.Kontent.Delivery.Abstractions;
 using System.Collections.Generic;
+using System.Threading.Tasks;
 
 namespace Kontent.Statiq.Tests.Tools
 {
@@ -15,6 +16,24 @@ public static IDeliveryClient WithFakeContent<TContent>(this IDeliveryClient cli
 
             return client;
         }
+
+        public static IDeliveryClient WithFakeContentFeed<TContent>(this IDeliveryClient client, params TContent[] content)
+        {
+            var response = A.Fake<IDeliveryItemsFeed<TContent>>();
+            var moreData = true;
+            A.CallTo(() => response.HasMoreResults).ReturnsLazily( _ => moreData );
+            A.CallTo(() => response.FetchNextBatchAsync()).ReturnsLazily(_ =>
+            {
+                moreData = false; // return a single batch
+                var data = A.Fake<IDeliveryItemsFeedResponse<TContent>>();
+                A.CallTo(() => data.Items).Returns(content);
+                return Task.FromResult(data);
+            });
+            A.CallTo(() => client.GetItemsFeed<TContent>(A<IEnumerable<IQueryParameter>>._))
+                .Returns(response);
+
+            return client;
+        }
 
         public static IDeliveryClient WithFakeTaxonomy(this IDeliveryClient client, params ITaxonomyGroup[] taxonomies)
         {

Kontent.Statiq.Tests/When_using_the_items_feed.cs

@@ -0,0 +1,47 @@
+using FakeItEasy;
+using FluentAssertions;
+using Kentico.Kontent.Delivery.Abstractions;
+using Kontent.Statiq.Tests.Models;
+using Kontent.Statiq.Tests.Tools;
+using Statiq.Common;
+using System;
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using Xunit;
+
+namespace Kontent.Statiq.Tests
+{
+    public class When_using_the_items_feed
+    {
+        [Fact]
+        public async Task It_should_invoke_the_correct_endpoint()
+        {
+            // Arrange
+            var content = new Article
+            {
+                System = new TestContentItemSystemAttributes
+                {
+                    Type = "article",
+                    Id = "cf106f4e-30a4-42ef-b313-b8ea3fd3e5c5",
+                    Language = "en-US",
+                    Codename = "coffee_beverages_explained",
+                    Name = "Coffee Beverages Explained",
+                    LastModified = new DateTime(2019, 09, 18, 10, 58, 38, 917)
+                }
+            };
+
+            var deliveryClient = A.Fake<IDeliveryClient>()
+                .WithFakeContentFeed(content);
+
+            var sut = new Kontent<Article>(deliveryClient)
+                .WithItemsFeed();
+
+            // Act
+            var docs = await sut.ExecuteAsync(A.Fake<IExecutionContext>());
+
+            // Assert
+            docs.Should().HaveCount(1);
+            A.CallTo(() => deliveryClient.GetItemsFeed<Article>(A<IEnumerable<IQueryParameter>>._)).MustHaveHappenedOnceExactly();
+        }
+    }
+}

Kontent.Statiq/Kontent.cs

@@ -18,6 +18,7 @@ public sealed class Kontent<TContentModel> : Module where TContentModel : class
         internal Func<TContentModel, string>? GetContent { get; set; }
 
         private readonly IDeliveryClient _client;
+        private bool _useItemFeed;
 
         internal List<IQueryParameter> QueryParameters { get; } = new List<IQueryParameter>();
 
@@ -29,16 +30,50 @@ public sealed class Kontent<TContentModel> : Module where TContentModel : class
         public Kontent(IDeliveryClient client)
         {
             _client = client ?? throw new ArgumentNullException(nameof(client), $"{nameof(client)} must not be null");
+            _useItemFeed = false;
         }
 
+        /// <summary>
+        /// Use the items-feed endpoint instead of the items endpoint.
+        /// <para>Use this when you have a lot of content and get a bad request response.</para>
+        /// </summary>
+        /// <returns>The module.</returns>
+        public Kontent<TContentModel> WithItemsFeed()
+        {
+            _useItemFeed = true;
+            return this;
+        }
+
         /// <inheritdoc />
         protected override async Task<IEnumerable<IDocument>> ExecuteContextAsync(IExecutionContext context)
         {
-            var items = await _client.GetItemsAsync<TContentModel>(QueryParameters);
+            if (_useItemFeed)
+            {
+                var feed = _client.GetItemsFeed<TContentModel>(QueryParameters);
+
+                var documents = new List<IDocument>();
+
+                while (feed.HasMoreResults)
+                {
+                    var nextBatch = await feed.FetchNextBatchAsync();
+
+                    var documentTasks = nextBatch.Items.Select(item => KontentDocumentHelpers.CreateDocument(context, item, GetContent)).ToArray();
+
+                    var documentBatch = await Task.WhenAll(documentTasks);
+
+                    documents.AddRange(documentBatch);
+                }
+
+                return documents;
+            }
+            else
+            {
+                var items = await _client.GetItemsAsync<TContentModel>(QueryParameters);
 
-            var documentTasks = items.Items.Select(item => KontentDocumentHelpers.CreateDocument(context, item, GetContent)).ToArray();
+                var documentTasks = items.Items.Select(item => KontentDocumentHelpers.CreateDocument(context, item, GetContent)).ToArray();
 
-            return await Task.WhenAll(documentTasks);
+                return await Task.WhenAll(documentTasks);    
+            }
         }
     }
 }

README.md

@@ -444,6 +444,10 @@ Implement and register a link resolver. See the [Kontent docs](https://github.co
 
 Make sure all your classes are in a namespace.
 
+> A _Bad request_ occurs while loading data from Kontent
+
+If you have a lot of content items, use the items-feed by calling `.WithItemsFeed()` method on the Kontent module.
+
 ## How do I build this repo?
 
 You'll need a .NET Core development setup: Windows, Mac, Linux with VisualStudio, VS Code or Rider.