added ${aspnet-user-isAuthenticated}

NLog.Web.AspNetCore/LayoutRenderers/AspNetUserIsAuthenticatedLayoutRenderer.cs

@@ -0,0 +1,40 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+using NLog.LayoutRenderers;
+using NLog.Web.LayoutRenderers;
+
+namespace NLog.Web.AspNetCore.LayoutRenderers
+{
+    /// <summary>
+    /// Is the user authenticated? 0 = not authenticated, 1 = authenticated
+    /// 
+    /// ${aspnet-user-isAuthenticated}
+    /// </summary>
+    [LayoutRenderer("aspnet-user-isAuthenticated")]
+    public class AspNetUserIsAuthenticatedLayoutRenderer : AspNetLayoutRendererBase
+    {
+        /// <summary>
+        /// Render 0 or 1
+        /// </summary>
+        /// <param name="builder"></param>
+        /// <param name="logEvent"></param>
+        protected override void DoAppend(StringBuilder builder, LogEventInfo logEvent)
+        {
+            var httpContext = HttpContextAccessor.HttpContext;
+            if (httpContext == null)
+            {
+                return;
+            }
+
+            if (httpContext.User?.Identity?.IsAuthenticated == true)
+            {
+                builder.Append(1);
+            }
+            else
+            {
+                builder.Append(0);
+            }
+        }
+    }
+}

NLog.Web/NLog.Web.csproj

@@ -70,6 +70,8 @@
     <Compile Include="..\NLog.Web.AspNetCore\LayoutRenderers\AspNetSessionValueLayoutRenderer.cs" />
     <Compile Include="..\NLog.Web.AspNetCore\LayoutRenderers\AspNetUserAuthTypeLayoutRenderer.cs" />
     <Compile Include="..\NLog.Web.AspNetCore\LayoutRenderers\AspNetUserIdentityLayoutRenderer.cs" />
+    <Compile Include="..\NLog.Web.AspNetCore\LayoutRenderers\AspNetUserIsAuthenticatedLayoutRenderer.cs" />
+
     <Compile Include="..\NLog.Web.AspNetCore\LayoutRenderers\IISInstanceNameLayoutRenderer.cs" />
     <Compile Include="..\NLog.Web.AspNetCore\LayoutRenderers\AspNetRequestReferrerRenderer.cs" />
     <Compile Include="..\NLog.Web.AspNetCore\LayoutRenderers\AspNetRequestUrlRenderer.cs" />