Move React server-side rendering into more general SpaServices package

src/Microsoft.AspNet.SpaServices/Prerendering/Prerenderer.cs

@@ -0,0 +1,32 @@
+using System;
+using System.Threading.Tasks;
+using Microsoft.AspNet.NodeServices;
+using Newtonsoft.Json.Linq;
+
+namespace Microsoft.AspNet.SpaServices.Prerendering
+{
+    public static class Prerenderer
+    {
+        private static Lazy<StringAsTempFile> nodeScript;
+        
+        static Prerenderer() {
+            nodeScript = new Lazy<StringAsTempFile>(() => {
+                var script = EmbeddedResourceReader.Read(typeof(Prerenderer), "/Content/Node/prerenderer.js");
+                return new StringAsTempFile(script); // Will be cleaned up on process exit
+            });
+        }
+        
+        public static async Task<RenderToStringResult> RenderToString(INodeServices nodeServices, string componentModuleName, string componentExportName, string requestAbsoluteUrl, string requestPathAndQuery) {
+            return await nodeServices.InvokeExport<RenderToStringResult>(nodeScript.Value.FileName, "renderToString", 
+                /* bootModulePath */ componentModuleName,
+                /* bootModuleExport */ componentExportName,
+                /* absoluteRequestUrl */ requestAbsoluteUrl,
+                /* requestPathAndQuery */ requestPathAndQuery);
+        }
+    }
+    
+    public class RenderToStringResult {
+        public string Html;
+        public JObject Globals;
+    }
+}