Provide a mechanism for IProductFeedGeneratrorService implementations to declare the format they generate. Use this format declaration to return the correct output within ProductFeedController.

Author: Ben White

src/Umbraco.Commerce.ProductFeeds.Core/Features/FeedGenerators/Application/FeedFormat.cs

@@ -0,0 +1,15 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Umbraco.Commerce.ProductFeeds.Core.Features.FeedGenerators.Application
+{
+    public enum FeedFormat
+    {
+        Unknown,
+        Xml,
+        Json
+    }
+}

src/Umbraco.Commerce.ProductFeeds.Core/Features/FeedGenerators/Application/IProductFeedGeneratorService.cs

@@ -1,3 +1,4 @@
+using System.Text.Json;
 using System.Xml;
 using Umbraco.Commerce.ProductFeeds.Core.Features.FeedSettings.Application;
 
@@ -14,6 +15,12 @@ public interface IProductFeedGeneratorService
         /// Returns a user friendly name of the value extractor.
         /// </summary>
         public string DisplayName { get; }
-        Task<XmlDocument> GenerateFeedAsync(ProductFeedSettingReadModel feedSetting);
+
+        /// <summary>
+        /// Returns the feed format that this generator can generate.
+        /// </summary>
+        public FeedFormat Format { get; }
+        Task<XmlDocument> GenerateXmlFeedAsync(ProductFeedSettingReadModel feedSetting) => throw new NotImplementedException();
+        Task<JsonDocument> GenerateJsonFeedAsync(ProductFeedSettingReadModel feedSetting) => throw new NotImplementedException();
     }
 }

src/Umbraco.Commerce.ProductFeeds.Core/Features/FeedGenerators/Implementations/GoogleMerchantCenterFeedService.cs

@@ -40,6 +40,8 @@ public class GoogleMerchantCenterFeedService : IProductFeedGeneratorService
 
         public string DisplayName => "Google Merchant Center Feed";
 
+        public FeedFormat Format => FeedFormat.Xml;
+
         public GoogleMerchantCenterFeedService(
             ILogger<GoogleMerchantCenterFeedService> logger,
             ICurrencyService currencyService,
@@ -62,7 +64,7 @@ public GoogleMerchantCenterFeedService(
         /// <param name="feedSetting"></param>
         /// <returns></returns>
         /// <exception cref="IdPropertyNodeMappingNotFoundException"></exception>
-        public async Task<XmlDocument> GenerateFeedAsync(ProductFeedSettingReadModel feedSetting)
+        public async Task<XmlDocument> GenerateXmlFeedAsync(ProductFeedSettingReadModel feedSetting)
         {
             ArgumentNullException.ThrowIfNull(feedSetting, nameof(feedSetting));
 

src/Umbraco.Commerce.ProductFeeds.Startup/Initializations/CustomRouting.cs

@@ -27,7 +27,7 @@ public void CreateRoutes(IEndpointRouteBuilder endpoints)
                 new
                 {
                     controller = "ProductFeed",
-                    Action = "Xml",
+                    Action = "Generate",
                 });
         }
     }

src/Umbraco.Commerce.ProductFeeds.Web/Apis/Publics/ProductFeedController.cs

@@ -1,3 +1,4 @@
+using System.Text.Json;
 using System.Threading.Tasks;
 using System.Xml;
 using Microsoft.AspNetCore.Mvc;
@@ -19,7 +20,7 @@ public ProductFeedController(
             _feedConfigService = feedConfigService;
         }
 
-        public async Task<IActionResult> Xml(string path)
+        public async Task<IActionResult> Generate(string path)
         {
             ProductFeedSettingReadModel? feedSettings = await _feedConfigService
                 .FindSettingAsync(new FindSettingParams { FeedRelativePath = path })
@@ -30,10 +31,20 @@ public async Task<IActionResult> Xml(string path)
             }
 
             IProductFeedGeneratorService feedGenerator = _feedGeneratorFactory.GetGenerator(feedSettings.FeedGeneratorId);
-            XmlDocument feed = await feedGenerator.GenerateFeedAsync(feedSettings);
 
-            var result = new XmlActionResult(feed) { Formatting = Formatting.Indented };
-            return result;
+            switch (feedGenerator.Format)
+            {
+                case FeedFormat.Xml:
+                    XmlDocument xmlFeed = await feedGenerator.GenerateXmlFeedAsync(feedSettings);
+                    var result = new XmlActionResult(xmlFeed) { Formatting = Formatting.Indented };
+                    return result;
+                case FeedFormat.Json:
+                    JsonDocument jsonFeed = await feedGenerator.GenerateJsonFeedAsync(feedSettings);
+                    var jsonResult = new JsonResult(jsonFeed.RootElement);
+                    return jsonResult;
+                default:
+                    return Problem("Unknown feed format.");
+            }
         }
     }
 }