public string FormatUsage <T>(string appName)
{
var usageBuilder = new StringBuilder();
usageBuilder.AppendLine(
$@"{appName} <option> <args> [optional parameters]
Options:");
foreach (var optionInfo in CommandLineOptionsHelper.EnumerateTypeOptionPropertyInfo(null, typeof(T), null))
{
if (optionInfo.FormattedShortName != null)
{
usageBuilder.Append(optionInfo.FormattedShortName);
if (optionInfo.FormattedLongName != null)
{
usageBuilder.AppendLine();
}
}
if (optionInfo.FormattedLongName != null)
{
usageBuilder.Append(optionInfo.FormattedLongName);
}
if (optionInfo.OptionAttribute.ArgumentDescription != null)
{
usageBuilder.Append($" <{optionInfo.OptionAttribute.ArgumentDescription}>");
}
if (optionInfo.OptionAttribute.Required)
{
usageBuilder.Append(" (required)");
}
usageBuilder.AppendLine();
if (optionInfo.OptionAttribute.Description != null)
{
usageBuilder.AppendLine(optionInfo.OptionAttribute.Description);
if (optionInfo.OptionAttribute.DefaultValue != null)
{
usageBuilder.AppendLine($"Default is {optionInfo.OptionAttribute.DefaultValue}.");
}
}
usageBuilder.AppendLine();
}
return(usageBuilder.ToString());
}
public T Parse <T>(string[] args)
{
var options = Activator.CreateInstance <T>();
var lookup = CommandLineOptionsHelper.BuildOptionNameLookup(options);
for (int i = 0; i < args.Length; i++)
{
var opt = args[i];
bool TryGetNextArg(out string arg)
{
arg = null;
if ((i + 1) > (args.Length - 1))
{
return(false);
}
arg = args[++i];
return(true);
}
string GetNextArg()
{
if (!TryGetNextArg(out var arg))
{
throw new MissingRequiredArgumentException($"Missing required argument for option: {opt}")
{
Option = opt
}
}
;
return(arg);
}
if (!lookup.TryGetValue(opt, out CommandLineOptionsHelper.OptionInfo optionInfo))
{
continue;
}
if (optionInfo.PropertyInfo.PropertyType == typeof(bool))
{
// Toggle
optionInfo.PropertyInfo.SetValue(optionInfo.Object, true);
}
else
{
// Simple value assignment
var arg = GetNextArg();
var converter = TypeDescriptor.GetConverter(optionInfo.PropertyInfo.PropertyType);
var value = converter.ConvertFromString(null, CultureInfo.InvariantCulture, arg);
optionInfo.PropertyInfo.SetValue(optionInfo.Object, value);
}
optionInfo.Assigned = true;
}
foreach (var lookupKvp in lookup)
{
var objProperty = lookupKvp.Value;
if (!objProperty.Assigned && (objProperty.OptionAttribute != null))
{
if (objProperty.OptionAttribute.Required)
{
throw new MissingRequiredOptionException($"Missing required option: {lookupKvp.Key}")
{
Option = lookupKvp.Key
}
}
;
if (objProperty.OptionAttribute.DefaultValue != null)
{
objProperty.PropertyInfo.SetValue(objProperty.Object, objProperty.OptionAttribute.DefaultValue);
}
}
}
return(options);
}
}
}
