Added default logger formatter

#59

Author: Caldas

src/SplunkLogger/LoggerFactoryExtensions.cs

@@ -9,6 +9,8 @@ namespace Splunk
     /// </summary>
     public static class LoggerFactoryExtensions
     {
+        static readonly ILoggerFormatter DefaultLoggerFormatter = new BasicLoggerFormatter();
+
         /// <summary>
         /// Add <see cref="T:Splunk.Providers.SplunkHECRawLoggerProvider"/> as provider to logger factory.
         /// </summary>
@@ -17,6 +19,8 @@ public static class LoggerFactoryExtensions
         /// <param name="formatter">Custom text formatter.</param>
         public static ILoggerFactory AddHECRawSplunkLogger(this ILoggerFactory loggerFactory, SplunkLoggerConfiguration configuration, ILoggerFormatter formatter = null)
         {
+            if (formatter == null)
+                formatter = DefaultLoggerFormatter;
             loggerFactory.AddProvider(new SplunkHECRawLoggerProvider(configuration, formatter));
             return loggerFactory;
         }
@@ -29,6 +33,8 @@ public static ILoggerFactory AddHECRawSplunkLogger(this ILoggerFactory loggerFac
         /// <param name="formatter">Custom text formatter.</param>
         public static ILoggerFactory AddHECJsonSplunkLogger(this ILoggerFactory loggerFactory, SplunkLoggerConfiguration configuration, ILoggerFormatter formatter = null)
         {
+            if (formatter == null)
+                formatter = DefaultLoggerFormatter;
             loggerFactory.AddProvider(new SplunkHECJsonLoggerProvider(configuration, formatter));
             return loggerFactory;
         }
@@ -41,6 +47,8 @@ public static ILoggerFactory AddHECJsonSplunkLogger(this ILoggerFactory loggerFa
         /// <param name="formatter">Custom text formatter.</param>
         public static ILoggerFactory AddTcpSplunkLogger(this ILoggerFactory loggerFactory, SplunkLoggerConfiguration configuration, ILoggerFormatter formatter = null)
         {
+            if (formatter == null)
+                formatter = DefaultLoggerFormatter;
             loggerFactory.AddProvider(new SplunkTcpLoggerProvider(configuration, formatter));
             return loggerFactory;
         }
@@ -53,6 +61,8 @@ public static ILoggerFactory AddTcpSplunkLogger(this ILoggerFactory loggerFactor
         /// <param name="formatter">Custom text formatter.</param>
         public static ILoggerFactory AddUdpSplunkLogger(this ILoggerFactory loggerFactory, SplunkLoggerConfiguration configuration, ILoggerFormatter formatter = null)
         {
+            if (formatter == null)
+                formatter = DefaultLoggerFormatter;
             loggerFactory.AddProvider(new SplunkUdpLoggerProvider(configuration, formatter));
             return loggerFactory;
         }