private static ValueOrError <CrontabSchedule> TryParse(string expression, ExceptionHandler onError)
{
if (expression == null)
{
throw new ArgumentNullException("expression");
}
var tokens = expression.Split(_separators, StringSplitOptions.RemoveEmptyEntries);
if (tokens.Length != 5)
{
return(ErrorHandling.OnError(() => new CrontabException(string.Format(
"'{0}' is not a valid crontab expression. It must contain at least 5 components of a schedule "
+ "(in the sequence of minutes, hours, days, months, days of week).",
expression)), onError));
}
var fields = new CrontabField[5];
for (var i = 0; i < fields.Length; i++)
{
var field = CrontabField.TryParse((CrontabFieldKind)i, tokens[i], onError);
if (field.IsError)
{
return(field.ErrorProvider);
}
fields[i] = field.Value;
}
return(new CrontabSchedule(fields[0], fields[1], fields[2], fields[3], fields[4]));
}
public static T TryParse <T>(string expression, ParseOptions options, Converter <CrontabSchedule, T> valueSelector, Converter <ExceptionProvider, T> errorSelector)
{
if (expression == null)
{
throw new ArgumentNullException("expression");
}
var tokens = expression.Split(StringSeparatorStock.Space, StringSplitOptions.RemoveEmptyEntries);
var includingSeconds = options != null && options.IncludingSeconds;
var expectedTokenCount = includingSeconds ? 6 : 5;
if (tokens.Length < expectedTokenCount || tokens.Length > expectedTokenCount)
{
return(errorSelector(() =>
{
var message = string.Format(
"'{0}' is an invalid crontab expression. It must contain {1}.",
expression,
includingSeconds
? "6 components of a schedule in the sequence of seconds, minutes, hours, days, months, and days of week"
: "5 components of a schedule in the sequence of minutes, hours, days, months, and days of week");
return new CrontabException(message);
}));
}
var fields = new CrontabField[6];
var offset = includingSeconds ? 0 : 1;
for (var i = 0; i < tokens.Length; i++)
{
var kind = (CrontabFieldKind)i + offset;
var field = CrontabField.TryParse(kind, tokens[i], v => new { ErrorProvider = (ExceptionProvider)null, Value = v },
e => new { ErrorProvider = e, Value = (CrontabField)null });
if (field.ErrorProvider != null)
{
return(errorSelector(field.ErrorProvider));
}
fields[i + offset] = field.Value;
}
return(valueSelector(new CrontabSchedule(fields[0], fields[1], fields[2], fields[3], fields[4], fields[5])));
}
