Add simpler prerendering API. Fixes #607

src/Microsoft.AspNetCore.SpaServices/Prerendering/DefaultSpaPrerenderer.cs

@@ -0,0 +1,49 @@
+using System.Threading;
+using Microsoft.AspNetCore.Hosting;
+using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.NodeServices;
+using System.Threading.Tasks;
+
+namespace Microsoft.AspNetCore.SpaServices.Prerendering
+{
+    /// <summary>
+    /// Default implementation of a DI service that provides convenient access to
+    /// server-side prerendering APIs. This is an alternative to prerendering via
+    /// the asp-prerender-module tag helper.
+    /// </summary>
+    internal class DefaultSpaPrerenderer : ISpaPrerenderer
+    {
+        private readonly string _applicationBasePath;
+        private readonly CancellationToken _applicationStoppingToken;
+        private readonly IHttpContextAccessor _httpContextAccessor;
+        private readonly INodeServices _nodeServices;
+
+        public DefaultSpaPrerenderer(
+            INodeServices nodeServices,
+            IApplicationLifetime applicationLifetime,
+            IHostingEnvironment hostingEnvironment,
+            IHttpContextAccessor httpContextAccessor)
+        {
+            _applicationBasePath = hostingEnvironment.ContentRootPath;
+            _applicationStoppingToken = applicationLifetime.ApplicationStopping;
+            _httpContextAccessor = httpContextAccessor;
+            _nodeServices = nodeServices;
+        }
+
+        public Task<RenderToStringResult> RenderToString(
+            string moduleName,
+            string exportName = null,
+            object customDataParameter = null,
+            int timeoutMilliseconds = default(int))
+        {
+            return Prerenderer.RenderToString(
+                _applicationBasePath,
+                _nodeServices,
+                _applicationStoppingToken,
+                new JavaScriptModuleExport(moduleName) { ExportName = exportName },
+                _httpContextAccessor.HttpContext,
+                customDataParameter,
+                timeoutMilliseconds);
+        }
+    }
+}