Allow Javascript engines to be bypassed entirely.

If no server-side rendering will occur on a page, for instance if
component render is called with clientOnly: true, it is
pointless to initialize a Javascript engine on the server. This allows the
consumer to easily disable all server side Javascript if the server is
under heavy load.

Author: Dustin Masters

src/React.AspNet/HtmlHelperExtensions.cs

@@ -5,26 +5,26 @@
  *  This source code is licensed under the BSD-style license found in the
  *  LICENSE file in the root directory of this source tree. An additional grant
  *  of patent rights can be found in the PATENTS file in the same directory.
- */
-
+ */
+
 using React.Exceptions;
-using React.TinyIoC;
-
+using React.TinyIoC;
+
 #if LEGACYASPNET
 using System.Web;
 using System.Web.Mvc;
-using IHtmlHelper = System.Web.Mvc.HtmlHelper;
+using IHtmlHelper = System.Web.Mvc.HtmlHelper;
 #else
 using Microsoft.AspNet.Mvc.Rendering;
 using IHtmlString = Microsoft.AspNet.Html.Abstractions.IHtmlContent;
 #endif
-
+
 #if LEGACYASPNET
-namespace React.Web.Mvc
+namespace React.Web.Mvc
 #else
 namespace React.AspNet
 #endif
-{
+{
 	/// <summary>
 	/// HTML Helpers for utilising React from an ASP.NET MVC application.
 	/// </summary>
@@ -81,7 +81,7 @@ public static IHtmlString React<T>(
 			string containerClass = null
 		)
 		{
-			var reactComponent = Environment.CreateComponent(componentName, props, containerId);
+			var reactComponent = Environment.CreateComponent(componentName, props, containerId, clientOnly);
 			if (!string.IsNullOrEmpty(htmlTag))
 			{
 				reactComponent.ContainerTag = htmlTag;
@@ -118,7 +118,7 @@ public static IHtmlString ReactWithInit<T>(
 			string containerClass = null
 		)
 		{
-			var reactComponent = Environment.CreateComponent(componentName, props, containerId);
+			var reactComponent = Environment.CreateComponent(componentName, props, containerId, clientOnly);
 			if (!string.IsNullOrEmpty(htmlTag))
 			{
 				reactComponent.ContainerTag = htmlTag;
@@ -146,9 +146,9 @@ public static IHtmlString ReactWithInit<T>(
 		/// attach event handlers to the server-rendered HTML.
 		/// </summary>
 		/// <returns>JavaScript for all components</returns>
-		public static IHtmlString ReactInitJavaScript(this IHtmlHelper htmlHelper)
+		public static IHtmlString ReactInitJavaScript(this IHtmlHelper htmlHelper, bool clientOnly = false)
 		{
-			var script = Environment.GetInitJavaScript();
+			var script = Environment.GetInitJavaScript(clientOnly);
 #if LEGACYASPNET
 			var tag = new TagBuilder("script")
 			{

src/React.Core/IReactEnvironment.cs

@@ -5,12 +5,11 @@
  *  This source code is licensed under the BSD-style license found in the
  *  LICENSE file in the root directory of this source tree. An additional grant 
  *  of patent rights can be found in the PATENTS file in the same directory.
- */
-
-using System;
-
+ */
+
+
 namespace React
-{
+{
 	/// <summary>
 	/// Request-specific ReactJS.NET environment. This is unique to the individual request and is 
 	/// not shared.
@@ -71,24 +70,26 @@ public interface IReactEnvironment
 		/// </summary>
 		/// <param name="name">Name of the variable</param>
 		/// <returns><c>true</c> if the variable exists; <c>false</c> otherwise</returns>
-		bool HasVariable(string name);
-
+		bool HasVariable(string name);
+
 		/// <summary>
 		/// Creates an instance of the specified React JavaScript component.
 		/// </summary>
 		/// <typeparam name="T">Type of the props</typeparam>
 		/// <param name="componentName">Name of the component</param>
 		/// <param name="props">Props to use</param>
 		/// <param name="containerId">ID to use for the container HTML tag. Defaults to an auto-generated ID</param>
+		/// <param name="clientOnly">True if server-side rendering will be bypassed. Defaults to false.</param>
 		/// <returns>The component</returns>
-		IReactComponent CreateComponent<T>(string componentName, T props, string containerId = null);
-
+		IReactComponent CreateComponent<T>(string componentName, T props, string containerId = null, bool clientOnly = false);
+
 		/// <summary>
 		/// Renders the JavaScript required to initialise all components client-side. This will 
 		/// attach event handlers to the server-rendered HTML.
 		/// </summary>
+		/// <param name="clientOnly">True if server-side rendering will be bypassed. Defaults to false.</param>
 		/// <returns>JavaScript for all components</returns>
-		string GetInitJavaScript();
+		string GetInitJavaScript(bool clientOnly = false);
 
 		/// <summary>
 		/// Gets the JSX Transformer for this environment.

src/React.Core/ReactComponent.cs

@@ -5,8 +5,8 @@
  *  This source code is licensed under the BSD-style license found in the
  *  LICENSE file in the root directory of this source tree. An additional grant
  *  of patent rights can be found in the PATENTS file in the same directory.
- */
-
+ */
+
 using System;
 using System.Linq;
 using System.Text.RegularExpressions;
@@ -15,7 +15,7 @@
 using React.Exceptions;
 
 namespace React
-{
+{
 	/// <summary>
 	/// Represents a React JavaScript component.
 	/// </summary>
@@ -89,7 +89,11 @@ public ReactComponent(IReactEnvironment environment, IReactSiteConfiguration con
 		/// <returns>HTML</returns>
 		public virtual string RenderHtml(bool renderContainerOnly = false, bool renderServerOnly = false)
 		{
-			EnsureComponentExists();
+			if (!renderContainerOnly)
+			{
+				EnsureComponentExists();
+			}
+
 			try
 			{
 				var html = string.Empty;

src/React.Core/ReactEnvironment.cs

@@ -5,21 +5,19 @@
  *  This source code is licensed under the BSD-style license found in the
  *  LICENSE file in the root directory of this source tree. An additional grant 
  *  of patent rights can be found in the PATENTS file in the same directory.
- */
-
+ */
+
 using System;
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Reflection;
 using System.Text;
 using System.Threading;
 using JavaScriptEngineSwitcher.Core;
-using JavaScriptEngineSwitcher.Core.Helpers;
-using Newtonsoft.Json;
 using React.Exceptions;
 
 namespace React
-{
+{
 	/// <summary>
 	/// Request-specific ReactJS.NET environment. This is unique to the individual request and is 
 	/// not shared.
@@ -247,39 +245,48 @@ public virtual bool HasVariable(string name)
 			{
 				throw WrapJavaScriptRuntimeException(ex);
 			}
-		}
-
+		}
+
 		/// <summary>
 		/// Creates an instance of the specified React JavaScript component.
 		/// </summary>
 		/// <typeparam name="T">Type of the props</typeparam>
 		/// <param name="componentName">Name of the component</param>
 		/// <param name="props">Props to use</param>
 		/// <param name="containerId">ID to use for the container HTML tag. Defaults to an auto-generated ID</param>
+		/// <param name="clientOnly">True if server-side rendering will be bypassed. Defaults to false.</param>
 		/// <returns>The component</returns>
-		public virtual IReactComponent CreateComponent<T>(string componentName, T props, string containerId = null)
-		{
-			EnsureUserScriptsLoaded();
+		public virtual IReactComponent CreateComponent<T>(string componentName, T props, string containerId = null, bool clientOnly = false)
+		{
+			if (!clientOnly)
+			{
+				EnsureUserScriptsLoaded();
+			}
+
 			var component = new ReactComponent(this, _config, componentName, containerId)
 			{
 				Props = props
 			};
 			_components.Add(component);
 			return component;
-		}
-
+		}
+
 		/// <summary>
 		/// Renders the JavaScript required to initialise all components client-side. This will 
 		/// attach event handlers to the server-rendered HTML.
 		/// </summary>
+		/// <param name="clientOnly">True if server-side rendering will be bypassed. Defaults to false.</param>
 		/// <returns>JavaScript for all components</returns>
-		public virtual string GetInitJavaScript()
+		public virtual string GetInitJavaScript(bool clientOnly = false)
 		{
-			var fullScript = new StringBuilder();
-			
-			// Propagate any server-side console.log calls to corresponding client-side calls.
-			var consoleCalls = Execute<string>("console.getCalls()");
-			fullScript.Append(consoleCalls);
+			var fullScript = new StringBuilder();
+
+			// Propagate any server-side console.log calls to corresponding client-side calls.
+			if (!clientOnly)
+			{
+				var consoleCalls = Execute<string>("console.getCalls()");
+				fullScript.Append(consoleCalls);
+			}
 
 			foreach (var component in _components)
 			{