/// <summary>
/// Creates a dictionary that is populated with key/value pairs from a command line
/// that supports syntax where options are provided in the form "/key=value".
/// This method supports the ability to specify delimiter characters for options in
/// the command line.
/// </summary>
/// <param name="arguments">Key/value pairs.</param>
/// <param name="keyCharacter">A character that precedes a key.</param>
/// <param name="valueCharacter">A character that separates a key from a value.</param>
/// <returns></returns>
public static CommandLineDictionary FromArguments(IEnumerable <string> arguments, char keyCharacter, char valueCharacter)
{
CommandLineDictionary cld = new CommandLineDictionary();
cld.KeyCharacter = keyCharacter;
cld.ValueCharacter = valueCharacter;
foreach (string argument in arguments)
{
cld.AddArgument(argument);
}
return(cld);
}
/// <summary>
/// Sets properties on an object from a series of key/value string
/// arguments that are in the form "/PropertyName=Value", where the
/// value is converted from a string into the property type.
/// </summary>
/// <param name="valueToPopulate">The object to set properties on.</param>
/// <param name="args">The key/value arguments describing the property names and values to set.</param>
/// <returns>
/// Indicates whether the properties were successfully set. Reasons for failure reasons include
/// a property name that does not exist or a value that cannot be converted from a string.
/// </returns>
/// <exception cref="System.ArgumentException">Thrown when one of the key/value strings cannot be parsed into a property.</exception>
public static void ParseArguments(this object valueToPopulate, IEnumerable <string> args)
{
CommandLineDictionary commandLineDictionary = CommandLineDictionary.FromArguments(args);
PropertyDescriptorCollection properties = TypeDescriptor.GetProperties(valueToPopulate);
// Ensure required properties are specified.
foreach (PropertyDescriptor property in properties)
{
// See whether any of the attributes on the property is a RequiredAttribute.
if (property.Attributes.Cast <Attribute>().Any(attribute => attribute is RequiredAttribute))
{
// If so, and the command line dictionary doesn't contain a key matching
// the property's name, it means that a required property isn't specified.
if (!commandLineDictionary.ContainsKey(property.Name))
{
throw new ArgumentException("A value for the " + property.Name + " property is required.");
}
}
}
foreach (KeyValuePair <string, string> keyValuePair in commandLineDictionary)
{
// Find a property whose name matches the kvp's key, ignoring case.
// We can't just use the indexer because that is case-sensitive.
PropertyDescriptor property = MatchProperty(keyValuePair.Key, properties, valueToPopulate.GetType());
// If the value is null/empty and the property is a bool, we
// treat it as a flag, which means its presence means true.
if (string.IsNullOrEmpty(keyValuePair.Value) && (property.PropertyType == typeof(bool) || property.PropertyType == typeof(bool?)))
{
property.SetValue(valueToPopulate, true);
continue;
}
object valueToSet;
// We support a limited set of collection types. Setting a List<T>
// is one of the most flexible types as it supports three different
// interfaces, but the catch is that we don't support the concrete
// Collection<T> type. We can expand it to support Collection<T>
// in the future, but the code will get a bit uglier.
switch (property.PropertyType.Name)
{
case "IEnumerable`1":
case "ICollection`1":
case "IList`1":
case "List`1":
MethodInfo methodInfo = typeof(CommandLineParser).GetMethod("FromCommaSeparatedList", BindingFlags.Static | BindingFlags.NonPublic);
Type[] genericArguments = property.PropertyType.GetGenericArguments();
MethodInfo genericMethodInfo = methodInfo.MakeGenericMethod(genericArguments);
valueToSet = genericMethodInfo.Invoke(null, new object[] { keyValuePair.Value });
break;
default:
TypeConverter typeConverter = TypeDescriptor.GetConverter(property.PropertyType);
if (typeConverter == null || !typeConverter.CanConvertFrom(typeof(string)))
{
throw new ArgumentException("Unable to convert from a string to a property of type " + property.PropertyType + ".");
}
valueToSet = typeConverter.ConvertFrom(keyValuePair.Value);
break;
}
property.SetValue(valueToPopulate, valueToSet);
}
}
