+ Added more descriptive help for default parameters

Author: trueromanus

src/ExampleApp/Program.cs

@@ -1,4 +1,5 @@
 using FlowCommandLine;
+using static FlowCommandLine.FlowCommandParameter;
 
 await CommandLine.Console ()
     .Application ( "Console Application", "1.0.0", "Application full description.", "Copyright (c) Macroloft All right Reserved", "conapp" )
@@ -9,10 +10,10 @@ await CommandLine.Console ()
             Console.WriteLine ( "Param2: " + parameters.Param2 );
         },
         "Command description",
-        new List<FlowCommandParameter> {
-            FlowCommandParameter.CreateRequired(alias: "param1", help: "parameter description"),
-            FlowCommandParameter.Create(alias: "param2", help: "parameter2 description"),
-        }
+        [
+            CreateDefault(alias: "param1", help: "parameter description"),
+            Create(alias: "param2", help: "parameter2 description"),
+        ]
     )
     .RunCommandAsync ();
 

src/FlowCommandLine/CommandLine.cs

@@ -251,7 +251,30 @@ private void ShowCommandHelp ( string description, List<FlowCommandParameter> pa
         }
 
         private void ShowParameters ( List<FlowCommandParameter> commandParameters ) {
-            if ( commandParameters.Any ( a => a.Required ) ) {
+            var defaultParameters = commandParameters.Where ( a => a.Default ).ToArray ();
+            if ( defaultParameters.Any () ) {
+                var allDefaultParameters = string.Join (
+                    " ",
+                    defaultParameters
+                    .Select (
+                        a =>
+                            string.Join ( '/', new List<string> { a.ShortName, a.FullName, a.PropertyName }.Where ( a => !string.IsNullOrEmpty ( a ) ) )
+                    )
+                    .ToArray ()
+                );
+                m_commandLineProvider.WriteLine ( $"Default parameters in follow order: {allDefaultParameters}" );
+                foreach ( var defaultParameter in defaultParameters ) {
+                    m_commandLineProvider.WriteLine (
+                        "  " + string.Join (
+                            '/',
+                            new List<string> { defaultParameter.ShortName, defaultParameter.FullName, defaultParameter.PropertyName }
+                                .Where ( a => !string.IsNullOrEmpty ( a ) )
+                        ) + " " + defaultParameter.Description
+                    );
+                }
+                m_commandLineProvider.WriteLine ( "" );
+            }
+            if ( commandParameters.Any ( a => a.Required && !a.Default ) ) {
                 m_commandLineProvider.WriteLine ( "The following arguments are available:" );
                 var requiredParameters = commandParameters
                     .Where ( a => a.Required )
@@ -291,6 +314,13 @@ private void ShowParameters ( List<FlowCommandParameter> commandParameters ) {
             }
         }
 
+        private void ShowApplicationUsage () {
+            if ( !string.IsNullOrEmpty ( m_applicationExecutable ) ) {
+                m_commandLineProvider.WriteLine ( $"usage: {m_applicationExecutable} [<command>] [<parameters>]" );
+                m_commandLineProvider.WriteLine ( " " );
+            }
+        }
+
         /// <summary>
         /// Show application help and a list of available commands.
         /// </summary>
@@ -303,14 +333,12 @@ private void ShowHelp ( List<string> parts, bool fullInfo = false ) {
                     m_commandLineProvider.WriteLine ( m_applicationDescription );
                     m_commandLineProvider.WriteLine ( " " );
                 }
-                if ( !string.IsNullOrEmpty ( m_applicationExecutable ) ) {
-                    m_commandLineProvider.WriteLine ( $"usage: {m_applicationExecutable} [<command>] [<parameters>]" );
-                    m_commandLineProvider.WriteLine ( " " );
-                }
 
                 if ( m_commands.Any () || m_asyncCommands.Any () ) {
                     if ( parts.Any ( IsHelpParameter ) && ShowHelpBySingleCommand ( parts ) ) return;
 
+                    ShowApplicationUsage ();
+
                     var maximumLength = m_commands
                         .Select ( a => a.Key )
                         .Concat ( m_asyncCommands.Select ( b => b.Key ) )
@@ -336,6 +364,8 @@ private void ShowHelp ( List<string> parts, bool fullInfo = false ) {
             } else {
                 if ( !parts.Any () ) return;
 
+                ShowApplicationUsage ();
+
                 var command = parts.First ();
                 if ( m_commands.ContainsKey ( command ) || m_asyncCommands.ContainsKey ( command ) ) {
                     m_commandLineProvider.WriteLine ( $" " );
@@ -363,16 +393,23 @@ private void ShowOptionsHelp () {
             if ( m_options.Any () ) ShowParameters ( m_options );
         }
 
+        private void ShowCommandUsage ( string command, bool haveDefault ) {
+            m_commandLineProvider.WriteLine ( $"usage: {m_applicationExecutable} {command}{( haveDefault ? " [default parameters]" : "" )} [<parameters>]" );
+            m_commandLineProvider.WriteLine ( " " );
+        }
+
         private bool ShowHelpBySingleCommand ( List<string> parts ) {
             var command = parts.First ();
 
             if ( m_commands.ContainsKey ( command ) ) {
                 var selectedCommand = m_commands[command];
+                ShowCommandUsage ( command, selectedCommand.Parameters.Any ( a => a.Default ) );
                 ShowCommandHelp ( selectedCommand.Description, selectedCommand.Parameters );
                 return true;
             }
             if ( m_asyncCommands.ContainsKey ( command ) ) {
                 var selectedCommand = m_asyncCommands[command];
+                ShowCommandUsage ( command, selectedCommand.Parameters.Any ( a => a.Default ) );
                 ShowCommandHelp ( selectedCommand.Description, selectedCommand.Parameters );
                 return true;
             }

src/FlowCommandLine/FlowCommandLine.csproj

@@ -16,7 +16,7 @@
 		<PackageTags>command,line,commandline,command-line,parse,parser,parsing,shell</PackageTags>
 		<PackageLicenseFile>LICENSE</PackageLicenseFile>
 		<PackageReadmeFile>README.md</PackageReadmeFile>
-		<Version>1.0.11.0</Version>
+		<Version>1.0.12.0</Version>
 		<IsTrimmable>true</IsTrimmable>
 		<PublishTrimmed>true</PublishTrimmed>
 		<PackageReleaseNotes>