Formats the inputed value based on the formatting system for this ruler.
        
        :param      value | <variant>

def formatValue( self, value ):
        """
        Formats the inputed value based on the formatting system for this ruler.
        
        :param      value | <variant>
        """
        formatter = self.formatter()
        if ( formatter is not None ):
            return formatter(value)
        
        elif ( self.format() ):
            rtype = self.rulerType()
            if ( rtype in (XChartRuler.Type.Date, XChartRuler.Type.Datetime,
                           XChartRuler.Type.Time) ):
                return value.toString(self.format())
            else:
                try:
                    return self.format() % value
                except TypeError:
                    return nativestring(value)
        
        return nativestring(value)