Merge pull request #15 from NLog/aspnet-item-renderer

Aspnet-item renderer

NLog.Web.Tests/LayoutRenderers/AspNetSessionValueLayoutRendererTests.cs

@@ -67,6 +67,90 @@ public void NestedProps()
             ExecTest("a", o, "c", appSettingLayoutRenderer);
         }
 
+        [TestMethod()]
+        public void NestedProps2()
+        {
+            var appSettingLayoutRenderer = new AspNetSessionValueLayoutRenderer()
+            {
+                Variable = "a.b.c",
+                EvaluateAsNestedProperties = true
+            };
+
+            var o = new { b = "c" };
+            //set in "a"
+            ExecTest("a", o, "", appSettingLayoutRenderer);
+        }
+
+        [TestMethod()]
+        public void NestedProps3()
+        {
+            var appSettingLayoutRenderer = new AspNetSessionValueLayoutRenderer()
+            {
+                Variable = "a.b..c",
+                EvaluateAsNestedProperties = true
+            };
+
+            var o = new { b = "c" };
+            //set in "a"
+            ExecTest("a", o, "", appSettingLayoutRenderer);
+        }
+
+        [TestMethod()]
+        public void EmptyPath()
+        {
+            var appSettingLayoutRenderer = new AspNetSessionValueLayoutRenderer()
+            {
+                Variable = "",
+                EvaluateAsNestedProperties = true
+            };
+
+            var o = new { b = "c" };
+            //set in "a"
+            ExecTest("a", o, "", appSettingLayoutRenderer);
+        }
+
+        [TestMethod()]
+        public void EmptyVarname()
+        {
+            var appSettingLayoutRenderer = new AspNetSessionValueLayoutRenderer()
+            {
+                Variable = "",
+                EvaluateAsNestedProperties = false
+            };
+
+            var o = new { b = "c" };
+            //set in "a"
+            ExecTest("a", o, "", appSettingLayoutRenderer);
+        }
+
+        [TestMethod()]
+        public void NullPath()
+        {
+            var appSettingLayoutRenderer = new AspNetSessionValueLayoutRenderer()
+            {
+                Variable = null,
+                EvaluateAsNestedProperties = true
+            };
+
+            var o = new { b = "c" };
+            //set in "a"
+            ExecTest("a", o, "", appSettingLayoutRenderer);
+        }
+
+        [TestMethod()]
+        public void NullVarname()
+        {
+            var appSettingLayoutRenderer = new AspNetSessionValueLayoutRenderer()
+            {
+                Variable = null,
+                EvaluateAsNestedProperties = false
+            };
+
+            var o = new { b = "c" };
+            //set in "a"
+            ExecTest("a", o, "", appSettingLayoutRenderer);
+        }
+
         /// <summary>
         /// set in Session and test
         /// </summary>

NLog.Web/Internal/PropertyReader.cs

@@ -0,0 +1,38 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace NLog.Web.Internal
+{
+    internal class PropertyReader
+    {
+        /// <summary>
+        /// Get value of a property
+        /// </summary>
+        /// <param name="key">key</param>
+        /// <param name="getVal">function to get a value with this key</param>
+        /// <param name="evaluateAsNestedProperties">evaluate <paramref name="key"/> as a nested property path. E.g. A.B is property B inside A.</param>
+        /// <returns>value</returns>
+        public static object GetValue(string key, Func<string, object> getVal, bool evaluateAsNestedProperties)
+        {
+            object value;
+            if (evaluateAsNestedProperties)
+            {
+                var path = key.Split(new[] { '.' }, StringSplitOptions.RemoveEmptyEntries);
+
+                value = getVal(path.First());
+
+                foreach (var property in path.Skip(1))
+                {
+                    var propertyInfo = value.GetType().GetProperty(property);
+                    value = propertyInfo.GetValue(value, null);
+                }
+            }
+            else
+            {
+                value = getVal(key);
+            }
+            return value;
+        }
+    }
+}

NLog.Web/LayoutRenderers/AspNetItemValueLayoutRenderer.cs

@@ -0,0 +1,77 @@
+using System;
+using System.Globalization;
+using System.Linq;
+using System.Text;
+using System.Web;
+using NLog.Config;
+using NLog.LayoutRenderers;
+using NLog.Web.Internal;
+
+namespace NLog.Web.LayoutRenderers
+{
+    /// <summary>
+    /// ASP.NET Item variable.
+    /// </summary>
+    /// <remarks>
+    /// Use this layout renderer to insert the value of the specified variable stored 
+    /// in the ASP.NET HttpContext.Current.Items dictionary.
+    /// </remarks>
+    /// <example>
+    /// <para>You can set the value of an ASP.NET Item variable by using the following code:</para>
+    /// <code lang="C#">
+    /// <![CDATA[
+    /// HttpContext.Current.Items["myvariable"] = 123;
+    /// HttpContext.Current.Items["stringvariable"] = "aaa BBB";
+    /// HttpContext.Current.Items["anothervariable"] = DateTime.Now;
+    /// ]]>
+    /// </code>
+    /// <para>Example usage of ${aspnet-item}:</para>
+    /// <code lang="NLog Layout Renderer">
+    /// ${aspnet-item:variable=myvariable} - produces "123"
+    /// ${aspnet-item:variable=anothervariable} - produces "01/01/2006 00:00:00"
+    /// ${aspnet-item:variable=anothervariable:culture=pl-PL} - produces "2006-01-01 00:00:00"
+    /// ${aspnet-item:variable=myvariable:padding=5} - produces "  123"
+    /// ${aspnet-item:variable=myvariable:padding=-5} - produces "123  "
+    /// ${aspnet-item:variable=stringvariable:upperCase=true} - produces "AAA BBB"
+    /// </code>
+    /// </example>
+    [LayoutRenderer("aspnet-item")]
+    public class AspNetItemValueLayoutRenderer : LayoutRenderer
+    {
+        /// <summary>
+        /// Gets or sets the item variable name.
+        /// </summary>
+        /// <docgen category='Rendering Options' order='10' />
+        [DefaultParameter]
+        public string Variable { get; set; }
+
+        /// <summary>
+        /// Gets or sets whether items with a dot are evaluated as properties or not
+        /// </summary>
+        /// <docgen category='Rendering Options' order='10' />
+        public bool EvaluateAsNestedProperties { get; set; }
+
+        /// <summary>
+        /// Renders the specified ASP.NET Item value and appends it to the specified <see cref="StringBuilder" />.
+        /// </summary>
+        /// <param name="builder">The <see cref="StringBuilder"/> to append the rendered data to.</param>
+        /// <param name="logEvent">Logging event.</param>
+        protected override void Append(StringBuilder builder, LogEventInfo logEvent)
+        {
+            if (Variable == null)
+            {
+                return;
+            }
+
+            HttpContext context = HttpContext.Current;
+            if (context == null)
+            {
+                return;
+            }
+
+            var value = PropertyReader.GetValue(Variable, k => context.Items[k], EvaluateAsNestedProperties);
+
+            builder.Append(Convert.ToString(value, CultureInfo.InvariantCulture));
+        }
+    }
+}

NLog.Web/LayoutRenderers/AspNetSessionValueLayoutRenderer.cs

@@ -3,8 +3,10 @@
 using System.Linq;
 using System.Text;
 using System.Web;
+using System.Web.SessionState;
 using NLog.Config;
 using NLog.LayoutRenderers;
+using NLog.Web.Internal;
 
 namespace NLog.Web.LayoutRenderers
 {
@@ -72,25 +74,7 @@ protected override void Append(StringBuilder builder, LogEventInfo logEvent)
             {
                 return;
             }
-
-
-            object value;
-            if (EvaluateAsNestedProperties)
-            {
-                var path = Variable.Split(new[] { '.' }, StringSplitOptions.RemoveEmptyEntries);
-
-                value = context.Session[path[0]];
-
-                foreach (var property in path.Skip(1))
-                {
-                    var propertyInfo = value.GetType().GetProperty(property);
-                    value = propertyInfo.GetValue(value, null);
-                } 
-            }
-            else
-            {
-                value = context.Session[Variable];
-            }
+            var value = PropertyReader.GetValue(Variable, k => context.Session[k], EvaluateAsNestedProperties);
 
             builder.Append(Convert.ToString(value, CultureInfo.InvariantCulture));
         }

NLog.Web/NLog.Web.csproj

@@ -54,12 +54,14 @@
   </ItemGroup>
   <ItemGroup>
     <Compile Include="LayoutRenderers\AspNetApplicationValueLayoutRenderer.cs" />
+    <Compile Include="LayoutRenderers\AspNetItemValueLayoutRenderer.cs" />
     <Compile Include="LayoutRenderers\AspNetRequestValueLayoutRenderer.cs" />
     <Compile Include="LayoutRenderers\AspNetSessionIDLayoutRenderer.cs" />
     <Compile Include="LayoutRenderers\AspNetSessionValueLayoutRenderer.cs" />
     <Compile Include="LayoutRenderers\AspNetUserAuthTypeLayoutRenderer.cs" />
     <Compile Include="LayoutRenderers\AspNetUserIdentityLayoutRenderer.cs" />
     <Compile Include="LayoutRenderers\IISInstanceNameLayoutRenderer.cs" />
+    <Compile Include="Internal\PropertyReader.cs" />
     <Compile Include="NLogHttpModule.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="Targets\AspNetTrace.cs" />

README.md

@@ -18,6 +18,7 @@ See [Target documentation at the NLog wiki](https://github.com/NLog/NLog/wiki/Ta
 * ${aspnet-application}
 * ${aspnet-request}
 * ${aspnet-session}
+* ${aspnet-item}
 * ${aspnet-sessionid}
 * ${aspnet-user-authtype}
 * ${aspnet-user-identity}