Added a conditional AntiForgery.

Author: NTaylorMullen

src/Microsoft.AspNet.Mvc.TagHelpers/FormTagHelper.cs

@@ -16,6 +16,7 @@ namespace Microsoft.AspNet.Mvc.TagHelpers
     public class FormTagHelper : TagHelper
     {
         private const string RouteAttributePrefix = "route-";
+        private static readonly bool DefaultAntiForgeryBehavior = true;
 
         [Activate]
         private ViewContext ViewContext { get; set; }
@@ -41,6 +42,12 @@ public class FormTagHelper : TagHelper
         /// </summary>
         public string Method { get; set; }
 
+        /// <summary>
+        /// Whether the anti-forgery token should be generated. Defaults to <c>true</c>.
+        /// </summary>
+        [HtmlAttributeName("anti-forgery")]
+        public bool? AntiForgery { get; set; }
+
         /// <inheritdoc />
         /// <remarks>Does nothing if <see cref="Action"/> contains a '/'.</remarks>
         public override void Process(TagHelperContext context, TagHelperOutput output)
@@ -78,9 +85,11 @@ public override void Process(TagHelperContext context, TagHelperOutput output)
 
                 output.Merge(tagBuilder);
 
-                // TODO: Make this behavior optional once https://github.com/aspnet/Razor/issues/121 is completed.
-                var antiForgeryTag = Generator.GenerateAntiForgery(ViewContext);
-                output.Content += antiForgeryTag.ToString(TagRenderMode.SelfClosing);
+                if (AntiForgery ?? DefaultAntiForgeryBehavior)
+                {
+                    var antiForgeryTag = Generator.GenerateAntiForgery(ViewContext);
+                    output.Content += antiForgeryTag.ToString(TagRenderMode.SelfClosing);
+                }
             }
         }