/// <summary>
/// Attempts to case compareToThis as an DateTime
/// to do the comparison. If the cast
/// fails, then it compares the current
/// value against DateTime.MinValue.
/// </summary>
/// <param name="compareToThis"></param>
/// <returns></returns>
public int CompareTo(object compareToThis)
{
System.Type type = compareToThis.GetType();
DateTime compareTo = DateTime.MinValue;
try
{
if (type == typeof(PropertyDateTime))
{
compareTo = ((PropertyDateTime)compareToThis).m_value;
}
else if (type == typeof(string))
{
compareTo = PropertyDateTime.ParseIso8601((string)compareToThis);
}
else
{
compareTo = (DateTime)compareToThis;
}
}
catch
{
compareTo = DateTime.MinValue;
}
return(this.m_value.CompareTo(compareTo));
}
/// <summary>
/// This method is useful if metadata values are already obtained and a
/// comparison is needed. The method compares val1 against val2.
/// If the types don't match, then the type of val1 is
/// used to determine the semantics of val2, and an attempt
/// to cast val2 into the same type of val1 is made. This is useful
/// when val1 is a uri/number and val2 is a string.
/// </summary>
/// <param name="val1">a value of some type</param>
/// <param name="val2">another value of the same type, or a string that can be cast into the type of val1</param>
/// <param name="ignoreCase">indicates if we should ignore the case for text-related comparisons</param>
/// <returns>a comparison result: 0, 1, -1</returns>
public static int CompareTagValues(object val1, object val2, bool ignoreCase)
{
string type1 = val1.GetType().ToString();
string type2 = val2.GetType().ToString();
object v1 = val1;
object v2 = val2;
if (type1 != type2)
{
// If the data types for the two objects don't match
// I do my best to convert the second object
// into a data type of the first object.
string strval2 = val2.ToString();
switch (type1)
{
case "System.Char":
v2 = strval2[0];
break;
case "System.String":
v2 = strval2;
break;
case "System.Boolean":
if ((strval2 == "0") || (strval2 == "no"))
{
v2 = false;
}
else if ((strval2 == "1") || (strval2 == "yes"))
{
v2 = true;
}
else
{
try
{
v2 = bool.Parse(strval2);
}
catch
{
v2 = strval2;
}
}
break;
case "System.Uri":
//Uri is an exception - we'll always compare as a string.
v2 = strval2;
break;
case "System.Byte":
v2 = byte.Parse(strval2);
break;
case "System.UInt16":
v2 = UInt16.Parse(strval2);
break;
case "System.UInt32":
v2 = UInt32.Parse(strval2);
break;
case "System.Int32":
v2 = Int32.Parse(strval2);
break;
case "System.Int16":
v2 = Int16.Parse(strval2);
break;
case "System.SByte":
v2 = sbyte.Parse(strval2);
break;
case "System.Single":
v2 = Single.Parse(strval2);
break;
case "System.Double":
v2 = Double.Parse(strval2);
break;
case "System.DateTime":
DateTimeFormatInfo formatInfo = PropertyDateTime.GetFormatInfo();
v2 = DateTime.Parse(strval2, formatInfo);
break;
default:
throw new Exception("Cannot recast object of " + type2 + " into object of " + type1);
}
}
return(CompareObject(v1, v2, ignoreCase));
}
