Merge pull request #3423 from NLog/all-props-skip-empty-values

${all-event-properties}: Added IncludeEmptyValues option

src/NLog/LayoutRenderers/AllEventPropertiesLayoutRenderer.cs

@@ -31,6 +31,8 @@
 // THE POSSIBILITY OF SUCH DAMAGE.
 // 
 
+using System.Collections;
+
 namespace NLog.LayoutRenderers
 {
     using System;
@@ -70,6 +72,14 @@ public AllEventPropertiesLayoutRenderer()
         /// <docgen category='Rendering Options' order='10' />
         public string Separator { get; set; }
 
+        /// <summary>
+        /// Get or set if empty values should be included.
+        ///
+        /// A value is empty when null or in case of a string, null or empty string.
+        /// </summary>
+        [DefaultValue(false)]
+        public bool IncludeEmptyValues { get; set; } = false;
+
 #if NET4_5
 
         /// <summary>
@@ -101,7 +111,7 @@ public string Format
 
                 _format = value;
 
-                var formatSplit = _format.Split(new [] { "[key]", "[value]" }, StringSplitOptions.None);
+                var formatSplit = _format.Split(new[] { "[key]", "[value]" }, StringSplitOptions.None);
                 if (formatSplit.Length == 3)
                 {
                     _beforeKey = formatSplit[0];
@@ -129,7 +139,12 @@ protected override void Append(StringBuilder builder, LogEventInfo logEvent)
                 var formatProvider = GetFormatProvider(logEvent);
 
                 bool first = true;
-                foreach (var property in GetProperties(logEvent))
+                IEnumerable<KeyValuePair<object, object>> properties = GetProperties(logEvent);
+                if (!IncludeEmptyValues)
+                {
+                    properties = properties.Where(p => !IsEmptyPropertyValue(p.Value));
+                }
+                foreach (var property in properties)
                 {
                     if (!first)
                     {
@@ -158,6 +173,16 @@ protected override void Append(StringBuilder builder, LogEventInfo logEvent)
             }
         }
 
+        private static bool IsEmptyPropertyValue(object value)
+        {
+            if (value is string s)
+            {
+                return string.IsNullOrEmpty(s);
+            }
+
+            return value == null;
+        }
+
 #if NET4_5
 
         /// <summary>
@@ -183,6 +208,7 @@ protected override void Append(StringBuilder builder, LogEventInfo logEvent)
         {
             var properties = logEvent.Properties;
 #if NET4_5
+
             if (IncludeCallerInformation)
             {
                 return properties;

tests/NLog.UnitTests/Layouts/AllEventPropertiesTests.cs

@@ -48,7 +48,7 @@ public void AllParametersAreSetToDefault()
         {
             var renderer = new AllEventPropertiesLayoutRenderer();
             var ev = BuildLogEventWithProperties();
-            
+
             var result = renderer.Render(ev);
 
             Assert.Equal("a=1, hello=world, 17=100", result);
@@ -141,8 +141,8 @@ public void AllEventWithFluent_without_callerInformation()
                 .Write();
 
 
-            AssertDebugLastMessage("m","Test=InfoWrite, coolness=200%, a=not b");
-            
+            AssertDebugLastMessage("m", "Test=InfoWrite, coolness=200%, a=not b");
+
         }
 
 #if NET3_5 || NET4_0
@@ -169,7 +169,7 @@ public void AllEventWithFluent_with_callerInformation()
                 </nlog>");
 
             LogManager.Configuration = configuration;
-      
+
             var logger = LogManager.GetCurrentClassLogger();
             logger.Debug()
                 .Message("This is a test fluent message '{0}'.", DateTime.Now.Ticks)
@@ -183,6 +183,31 @@ public void AllEventWithFluent_with_callerInformation()
             AssertDebugLastMessageContains("m", "CallerLineNumber=");
         }
 
+        [Theory]
+        [InlineData(null, "a=1, hello=world, 17=100, notempty=0")]
+        [InlineData(false, "a=1, hello=world, 17=100, notempty=0")]
+        [InlineData(true, "a=1, hello=world, 17=100, empty1=, empty2=, notempty=0")]
+        public void IncludeEmptyValuesTest(bool? includeEmptyValues, string expected)
+        {
+            // Arrange
+            var renderer = new AllEventPropertiesLayoutRenderer();
+            if (includeEmptyValues != null)
+            {
+                renderer.IncludeEmptyValues = includeEmptyValues.Value;
+            }
+
+            var ev = BuildLogEventWithProperties();
+            ev.Properties["empty1"] = null;
+            ev.Properties["empty2"] = "";
+            ev.Properties["notempty"] = 0;
+
+            // Act
+            var result = renderer.Render(ev);
+
+            // Assert
+            Assert.Equal(expected, result);
+        }
+
         private static LogEventInfo BuildLogEventWithProperties()
         {
             var ev = new LogEventInfo();