private static void SetArrayType(FieldInfo field, string value, ProgramOptionsAttribute options, Func <Type, string, object> customValueParser)
{
var index = 0;
var values = SplitCollectionValues(options, value);
var arrayType = field.FieldType;
var array = (Array)field.GetValue(null);
if (array != null)
{
var oldArray = array;
array = (Array)Activator.CreateInstance(arrayType, new object[] { oldArray.Length + values.Length });
Array.Copy(oldArray, array, oldArray.Length);
index = oldArray.Length;
}
else
{
array = (Array)Activator.CreateInstance(arrayType, new object[] { values.Length });
}
foreach (var v in values)
{
array.SetValue(ParseValue(arrayType.GetElementType(), v, customValueParser), index++);
}
field.SetValue(null, array);
}
private static Action <string> ActionFor(ProgramOptionsAttribute options, FieldInfo field, Func <Type, string, object> customValueParser)
{
if (field.FieldType.IsArray && IsFlagsEnum(field.FieldType.GetElementType()))
{
throw new NotSupportedException("The parsing of a flags array is not supported. There would be no way to know which values to combine together into each element in the array");
}
if (field.FieldType.IsArray)
{
return(v => SetArrayType(field, v, options, customValueParser));
}
if (IsListField(field))
{
return(v => SetListType(field, v, options, customValueParser));
}
if (field.FieldType == typeof(bool))
{
return(v => SetBoolType(field, v));
}
if (IsFlagsEnum(field.FieldType))
{
return(v => SetFlagsEnumType(field, v, options));
}
return(v => SetBasicType(field, v, customValueParser));
}
private static IEnumerable <string> OptionNamesFor(ProgramOptionsAttribute options, FieldInfo field)
{
var name = NormalizeName(field.Name);
if (field.FieldType != typeof(bool))
{
name += "=";
}
if (options.Group == null)
{
yield return(name);
yield return(NormalizeName(field.DeclaringType.Name) + "." + name);
}
else
{
yield return(options.Group + "." + name);
}
foreach (var aliasAttr in field.GetCustomAttributes(typeof(OptionAliasAttribute), false))
{
if (field.FieldType != typeof(bool))
{
yield return($"{((OptionAliasAttribute)aliasAttr).Name}=");
}
else
{
yield return(((OptionAliasAttribute)aliasAttr).Name);
}
}
}
private static void SetFlagsEnumType(FieldInfo field, string value, ProgramOptionsAttribute options)
{
int finalValue =
SplitCollectionValues(options, value)
.Select(v => (int)ParseEnumValue(field.FieldType, v))
.Aggregate(0, (accum, current) => accum | current);
field.SetValue(null, finalValue);
}
private static void SetListType(FieldInfo field, string value, ProgramOptionsAttribute options, Func <Type, string, object> customValueParser)
{
var listType = field.FieldType;
var list = (IList)field.GetValue(null) ?? (IList)Activator.CreateInstance(listType);
foreach (var v in SplitCollectionValues(options, value))
{
list.Add(ParseValue(listType.GetGenericArguments()[0], v, customValueParser));
}
field.SetValue(null, list);
}
private static Action <string> ActionFor(ProgramOptionsAttribute options, FieldInfo field)
{
private static string[] SplitCollectionValues(ProgramOptionsAttribute options, string value)
{
return(value.Split(new[] { options.CollectionSeparator ?? "," }, StringSplitOptions.None));
}