FilteringWrapper - Fix XSD for Filter-property

src/NLog/Targets/Wrappers/FilteringTargetWrapper.cs

@@ -104,6 +104,7 @@ public FilteringTargetWrapper(Target wrappedTarget, ConditionExpression conditio
         /// </summary>
         /// <docgen category='Filtering Options' order='10' />
         [RequiredParameter]
+        [NLogConfigurationIgnoreProperty]
         public Filter Filter { get; set; }
 
         /// <inheritdoc/>

tests/NLog.UnitTests/Targets/Wrappers/FilteringTargetWrapperTests.cs

@@ -31,6 +31,8 @@
 // THE POSSIBILITY OF SUCH DAMAGE.
 // 
 
+using NLog.Filters;
+
 namespace NLog.UnitTests.Targets.Wrappers
 {
     using System;
@@ -43,7 +45,7 @@ namespace NLog.UnitTests.Targets.Wrappers
     using Xunit;
 
     public class FilteringTargetWrapperTests : NLogTestBase
-	{
+    {
         [Fact]
         public void FilteringTargetWrapperSyncTest1()
         {
@@ -301,6 +303,57 @@ public void FilteringTargetWrapperWhenRepeatedFilter()
             Assert.Equal(5, myTarget.Logs.Count);
         }
 
+        [Fact]
+        public void FilteringTargetWrapperWithConditionAttribute_correctBehavior()
+        {
+            // Arrange
+            LogManager.Configuration = CreateConfigWithCondition();
+            var myTarget = LogManager.Configuration.FindTargetByName<MemoryTarget>("memory");
+
+            // Act
+            var logger = LogManager.GetLogger(nameof(FilteringTargetWrapperWhenRepeatedFilter));
+            logger.Info("Hello World");
+            logger.Info("2");     // Will be ignored
+            logger.Info("3");     // Will be ignored
+            LogManager.Flush();
+
+            // Assert
+            Assert.Equal(1, myTarget.Logs.Count);
+        }
+
+        [Fact]
+        public void FilteringTargetWrapperWithConditionAttribute_validCondition()
+        {
+            // Arrange
+            var expectedCondition = "(length(message) > 2)";
+
+            // Act
+            var config = CreateConfigWithCondition();
+
+            // Assert
+            var myTarget = config.FindTargetByName<FilteringTargetWrapper>("target1");
+
+            Assert.Equal(expectedCondition, myTarget.Condition?.ToString());
+            var conditionBasedFilter = Assert.IsType<ConditionBasedFilter>(myTarget.Filter);
+            Assert.Equal(expectedCondition, conditionBasedFilter.Condition?.ToString());
+        }
+
+        private static XmlLoggingConfiguration CreateConfigWithCondition()
+        {
+            return XmlLoggingConfiguration.CreateFromXmlString(@"
+            <nlog>
+                <targets>
+                      <target name='target1' type='FilteringWrapper' condition='length(message) &gt; 2' >
+                        <target name='memory' type='Memory' />
+                  </target>
+                </targets>
+                <rules>
+                    <logger name='*' minlevel='Debug' writeTo='target1'/>
+                </rules>
+            </nlog>");
+        }
+
+
         class MyAsyncTarget : Target
         {
             public int WriteCount { get; private set; }

tools/MakeNLogXSD/XsdFileGenerator.cs

@@ -313,7 +313,7 @@ private static string GetXsdType(string apiTypeName, bool attribute)
                     return attribute ? "SimpleLayoutAttribute" : "Layout";
 
                 case "NLog.Filters.Filter":
-                    return "Filter";
+                    return attribute ? "xs:string" : "Filter";
 
                 case "Condition":
                     return "Condition";