protected MetricUnit()
{
//access the SIUnitAttribute
MemberInfo info = this.GetType();
object[] attributes = (object[])info.GetCustomAttributes(true);
//get the UnitAttribute
MetricUnitAttribute siua = (MetricUnitAttribute)attributes.SingleOrDefault <object>(ut => ut is MetricUnitAttribute);
if (siua != null)
{
defaultUnitPrefix = MetricPrefix.FromPrefixName(siua.SiPrefix.ToString());
unitPrefix = MetricPrefix.FromPrefixName(siua.SiPrefix.ToString());
}
else
{
throw new UnitException("SIUnitAttribute Not Found");
}
//ReferenceUnit attribute may or may not appear
// if it appears then the unit is not a default SI unit
// but act as SI Unit {means take prefixes}. and accepted by the SI poids
// however the code of reference unit is in the base class code.
}
/// <summary>
/// Gets the default unit type of quantity type parameter based on the unit system (namespace)
/// under the Units name space.
/// The Default Unit Type for length in Imperial is Foot for example.
/// </summary>
/// <param name="quantityType">quantity type</param>
/// <param name="unitSystem">The Unit System or explicitly the namespace under Units Namespace</param>
/// <returns>Unit Type Based on the unit system</returns>
public static Type GetDefaultUnitTypeOf(Type quantityType, string unitSystem)
{
unitSystem = unitSystem.ToUpperInvariant();
if (unitSystem.Contains("METRIC.SI"))
{
Type oUnitType = GetDefaultSIUnitTypeOf(quantityType);
return(oUnitType);
}
else
{
//getting the generic type
if (!quantityType.IsGenericTypeDefinition)
{
//the passed type is AnyQuantity<object> for example
//I want to get the type without type parameters AnyQuantity<>
quantityType = quantityType.GetGenericTypeDefinition();
}
//predictor of default unit.
Func <Type, bool> SearchForQuantityType = unitType =>
{
//search in the attributes of the unit type
MemberInfo info = unitType as MemberInfo;
object[] attributes = (object[])info.GetCustomAttributes(true);
//get the UnitAttribute
UnitAttribute ua = (UnitAttribute)attributes.SingleOrDefault <object>(ut => ut is UnitAttribute);
if (ua != null)
{
if (ua.QuantityType == quantityType)
{
if (ua is DefaultUnitAttribute)
{
//explicitly default unit.
return(true);
}
else if (ua is MetricUnitAttribute)
{
//check if the unit has SystemDefault flag true or not.
MetricUnitAttribute mua = ua as MetricUnitAttribute;
if (mua.SystemDefault)
{
return(true);
}
else
{
return(false);
}
}
else
{
return(false);
}
}
else
{
return(false);
}
}
else
{
return(false);
}
};
string CurrentUnitSystem = unitSystem; //
Type SystemUnitType = null;
//search in upper namespaces also to get the default unit of the parent system.
while (string.IsNullOrEmpty(CurrentUnitSystem) == false && SystemUnitType == null)
{
//prepare the query that we will search in
var SystemUnitTypes = from ut in UnitTypes
where ut.Namespace.ToUpperInvariant().EndsWith(CurrentUnitSystem, StringComparison.Ordinal) ||
ut.Namespace.ToUpperInvariant().EndsWith("SHARED", StringComparison.Ordinal)
select ut;
//select the default by predictor from the query
SystemUnitType = SystemUnitTypes.SingleOrDefault(
SearchForQuantityType
);
if (CurrentUnitSystem.LastIndexOf('.') < 0)
{
CurrentUnitSystem = "";
}
else
{
CurrentUnitSystem = CurrentUnitSystem.Substring(0, CurrentUnitSystem.LastIndexOf('.'));
}
}
if (SystemUnitType == null && unitSystem.Contains("METRIC"))
{
//try another catch for SI unit for this quantity
// because SI and metric units are disordered for now
// so if the search of unit in parent metric doesn't exist then search for it in SI units.
SystemUnitType = GetDefaultSIUnitTypeOf(quantityType);
}
return(SystemUnitType);
}
}