Merge pull request #557 from moh-hassan/HelpText

Enhance HelpText customization using a new overload AutoBuild method.

Author: moh-hassan

src/CommandLine/Text/CopyrightInfo.cs

@@ -27,11 +27,11 @@ public class CopyrightInfo
         /// <summary>
         /// An empty object used for initialization.
         /// </summary>
-        public static CopyrightInfo Empty 
+        public static CopyrightInfo Empty
         {
             get
             {
-               return new CopyrightInfo("author", 1); 
+                return new CopyrightInfo("author", DateTime.Now.Year);
             }
         }
 
@@ -115,12 +115,13 @@ public static CopyrightInfo Default
                     case MaybeType.Just:
                         return new CopyrightInfo(copyrightAttr.FromJustOrFail());
                     default:
-                        // if no copyright attribute exist but a company attribute does, use it as copyright holder
-                        return new CopyrightInfo(
-                                ReflectionHelper.GetAttribute<AssemblyCompanyAttribute>().FromJustOrFail(
-                                    new InvalidOperationException("CopyrightInfo::Default requires that you define AssemblyCopyrightAttribute or AssemblyCompanyAttribute.")
-                                ).Company,
-                                DateTime.Now.Year);
+                        var companyAttr = ReflectionHelper.GetAttribute<AssemblyCompanyAttribute>();
+                        return companyAttr.IsNothing()
+                            //if both copyrightAttr and companyAttr aren't available in Assembly,don't fire Exception
+                            ? Empty
+                            // if no copyright attribute exist but a company attribute does, use it as copyright holder
+                            : new CopyrightInfo(companyAttr.FromJust().Company, DateTime.Now.Year);
+                        
                 }
             }
         }
@@ -192,4 +193,4 @@ protected virtual string FormatYears(int[] years)
             return yearsPart.ToString();
         }
     }
-}
+}

src/CommandLine/Text/HelpText.cs

@@ -266,7 +266,7 @@ public bool AdditionalNewLineAfterOption
         /// </summary>
         public bool AddNewLineBetweenHelpSections
         {
-            get {  return addNewLineBetweenHelpSections; }
+            get { return addNewLineBetweenHelpSections; }
             set { addNewLineBetweenHelpSections = value; }
         }
 
@@ -389,7 +389,7 @@ public static HelpText AutoBuild<T>(
         }
 
         /// <summary>
-        /// Creates a new instance of the <see cref="CommandLine.Text.HelpText"/> class,
+        /// Creates a default instance of the <see cref="CommandLine.Text.HelpText"/> class,
         /// automatically handling verbs or options scenario.
         /// </summary>
         /// <param name='parserResult'>The <see cref="CommandLine.ParserResult{T}"/> containing the instance that collected command line arguments parsed with <see cref="CommandLine.Parser"/> class.</param>
@@ -400,6 +400,23 @@ public static HelpText AutoBuild<T>(
         /// <remarks>This feature is meant to be invoked automatically by the parser, setting the HelpWriter property
         /// of <see cref="CommandLine.ParserSettings"/>.</remarks>
         public static HelpText AutoBuild<T>(ParserResult<T> parserResult, int maxDisplayWidth = DefaultMaximumLength)
+        {
+            return AutoBuild<T>(parserResult, h => h, maxDisplayWidth);
+        }
+
+        /// <summary>
+        /// Creates a custom instance of the <see cref="CommandLine.Text.HelpText"/> class,
+        /// automatically handling verbs or options scenario.
+        /// </summary>
+        /// <param name='parserResult'>The <see cref="CommandLine.ParserResult{T}"/> containing the instance that collected command line arguments parsed with <see cref="CommandLine.Parser"/> class.</param>
+        ///  <param name='onError'>A delegate used to customize the text block of reporting parsing errors text block.</param>
+        /// <param name="maxDisplayWidth">The maximum width of the display.</param>
+        /// <returns>
+        /// An instance of <see cref="CommandLine.Text.HelpText"/> class.
+        /// </returns>
+        /// <remarks>This feature is meant to be invoked automatically by the parser, setting the HelpWriter property
+        /// of <see cref="CommandLine.ParserSettings"/>.</remarks>
+        public static HelpText AutoBuild<T>(ParserResult<T> parserResult, Func<HelpText, HelpText> onError, int maxDisplayWidth = DefaultMaximumLength)
         {
             if (parserResult.Tag != ParserResultType.NotParsed)
                 throw new ArgumentException("Excepting NotParsed<T> type.", "parserResult");
@@ -410,13 +427,25 @@ public static HelpText AutoBuild<T>(ParserResult<T> parserResult, int maxDisplay
                 return new HelpText($"{HeadingInfo.Default}{Environment.NewLine}") { MaximumDisplayWidth = maxDisplayWidth }.AddPreOptionsLine(Environment.NewLine);
 
             if (!errors.Any(e => e.Tag == ErrorType.HelpVerbRequestedError))
-                return AutoBuild(parserResult, current => DefaultParsingErrorsHandler(parserResult, current), e => e, maxDisplayWidth: maxDisplayWidth);
+                return AutoBuild(parserResult, current =>
+                {
+                    onError?.Invoke(current);
+                    return DefaultParsingErrorsHandler(parserResult, current);
+                }, e => e, maxDisplayWidth: maxDisplayWidth);
 
             var err = errors.OfType<HelpVerbRequestedError>().Single();
-            var pr = new NotParsed<object>(TypeInfo.Create(err.Type), Enumerable.Empty<Error>());
+            var pr = new NotParsed<object>(TypeInfo.Create(err.Type), new Error[] { err });
             return err.Matched
-                ? AutoBuild(pr, current => DefaultParsingErrorsHandler(pr, current), e => e, maxDisplayWidth: maxDisplayWidth)
-                : AutoBuild(parserResult, current => DefaultParsingErrorsHandler(parserResult, current), e => e, true, maxDisplayWidth);
+                  ? AutoBuild(pr, current =>
+                {
+                    onError?.Invoke(current);
+                    return DefaultParsingErrorsHandler(pr, current);
+                }, e => e, maxDisplayWidth: maxDisplayWidth)
+                : AutoBuild(parserResult, current =>
+                {
+                    onError?.Invoke(current);
+                    return DefaultParsingErrorsHandler(parserResult, current);
+                }, e => e, true, maxDisplayWidth);
         }
 
         /// <summary>
@@ -431,7 +460,6 @@ public static HelpText DefaultParsingErrorsHandler<T>(ParserResult<T> parserResu
 
             if (((NotParsed<T>)parserResult).Errors.OnlyMeaningfulOnes().Empty())
                 return current;
-
             var errors = RenderParsingErrorsTextAsLines(parserResult,
                 current.SentenceBuilder.FormatError,
                 current.SentenceBuilder.FormatMutuallyExclusiveSetErrors,
@@ -732,8 +760,8 @@ public override string ToString()
             var result = new StringBuilder(sbLength);
 
             result.Append(heading)
-                    .AppendWhen(!string.IsNullOrEmpty(copyright), 
-                        Environment.NewLine, 
+                    .AppendWhen(!string.IsNullOrEmpty(copyright),
+                        Environment.NewLine,
                         copyright)
                     .AppendWhen(preOptionsHelp.SafeLength() > 0,
                         NewLineIfNeededBefore(preOptionsHelp),
@@ -743,15 +771,15 @@ public override string ToString()
                         Environment.NewLine,
                         Environment.NewLine,
                         optionsHelp.SafeToString())
-                    .AppendWhen(postOptionsHelp.SafeLength() > 0, 
+                    .AppendWhen(postOptionsHelp.SafeLength() > 0,
                         NewLineIfNeededBefore(postOptionsHelp),
                         Environment.NewLine,
                         postOptionsHelp.ToString());
 
             string NewLineIfNeededBefore(StringBuilder sb)
             {
-                if (AddNewLineBetweenHelpSections 
-                        && result.Length > 0 
+                if (AddNewLineBetweenHelpSections
+                        && result.Length > 0
                         && !result.SafeEndsWith(Environment.NewLine)
                         && !sb.SafeStartsWith(Environment.NewLine))
                     return Environment.NewLine;
@@ -952,7 +980,7 @@ specification is OptionSpecification optionSpecification &&
 
             if (optionGroupSpecification != null)
             {
-                optionHelpText = "({0}: {1}) ".FormatInvariant(optionGroupWord, optionGroupSpecification.Group)  + optionHelpText;
+                optionHelpText = "({0}: {1}) ".FormatInvariant(optionGroupWord, optionGroupSpecification.Group) + optionHelpText;
             }
 
             //note that we need to indent trim the start of the string because it's going to be