Fix HttpClient injection on server-side blazor

src/Server/Startup.cs

@@ -1,10 +1,13 @@
 using Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.Components;
 using Microsoft.AspNetCore.Hosting;
 using Microsoft.AspNetCore.ResponseCompression;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Hosting;
 using Newtonsoft.Json.Serialization;
+using System;
 using System.Linq;
+using System.Net.Http;
 
 namespace tmp.Server
 {
@@ -20,6 +23,21 @@ namespace tmp.Server
                 opts.MimeTypes = ResponseCompressionDefaults.MimeTypes.Concat(
                     new[] { "application/octet-stream" });
             });
+				
+						// Server Side Blazor doesn't register HttpClient by default
+            if (!services.Any(x => x.ServiceType == typeof(HttpClient)))
+            {
+                // Setup HttpClient for server side in a client side compatible fashion
+                services.AddScoped<HttpClient>(s =>
+                {
+                    // Creating the URI helper needs to wait until the JS Runtime is initialized, so defer it.      
+                    var uriHelper = s.GetRequiredService<NavigationManager>();
+                    return new HttpClient
+                    {
+                        BaseAddress = new Uri(uriHelper.BaseUri)
+                    };
+                });
+            }
         }
 
         // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.

src/Server/Steeltoe.Server.csproj

@@ -12,6 +12,7 @@
   <ItemGroup>
     <PackageReference Include="Microsoft.AspNetCore.Blazor.Server" Version="3.0.0-preview9.19465.2" />
     <PackageReference Include="Microsoft.AspNetCore.Mvc.NewtonsoftJson" Version="3.0.0" />
+    <PackageReference Include="System.Net.Http" Version="4.3.4" />
   </ItemGroup>
 
   <ItemGroup>