internal static DateTimeStyles ToDateTimeStyles(DateTimeAssumption dateTimeAssumption)
{
System.Diagnostics.Debug.Assert(dateTimeAssumption == DateTimeAssumption.AssumeLocal || dateTimeAssumption == DateTimeAssumption.AssumeUniversal);
switch (dateTimeAssumption)
{
case DateTimeAssumption.AssumeLocal: return DateTimeStyles.AssumeLocal;
case DateTimeAssumption.AssumeUniversal: return DateTimeStyles.AssumeUniversal;
}
return DateTimeStyles.AssumeUniversal; // Just to make it compile. This line will never be reached.
}
// We cannot use TestCase attribute because arbitraryUniversalDateTime, arbitraryLocalDateTime, and arbitraryUnspecifiedDateTime are not compile time constants.
private static void ToDateTime__ValueIsInAnyStandardDateTimeFormat_FormatKnow_ValidAssumption_CurrentCulture__ReturnsEquivalentDateTime(DateTimeAssumption dateTimeAssumption, DateTime dateTime)
{
// JUst to be sure that the calling test is properly written.
Assert.That(dateTimeAssumption == DateTimeAssumption.AssumeLocal && dateTime.Kind == DateTimeKind.Local ||
dateTimeAssumption == DateTimeAssumption.AssumeUniversal && dateTime.Kind == DateTimeKind.Utc ||
dateTimeAssumption == DateTimeAssumption.AssumeLocal && dateTime.Kind == DateTimeKind.Unspecified);
Console.WriteLine("{0}-- {1} -- ({2}){0}", Environment.NewLine, dateTime.ToString(StandardDateTimeFormats.GeneralDateLongTime), dateTimeAssumption);
foreach (string standardDateTimeFormat in StandardDateTimeFormats.AllStandardDateTimeFormats)
{
Console.WriteLine("{0} - {1}", standardDateTimeFormat, dateTime.ToString(standardDateTimeFormat));
DateTime? result = StringConvert.ToDateTime(dateTime.ToString(standardDateTimeFormat), standardDateTimeFormat, CultureInfo.CurrentCulture, dateTimeAssumption);
Assert.That(result.HasValue);
// We know now that the result has value and that result.Value will not throw InvalidOperationException.
// ReSharper disable PossibleInvalidOperationException
Console.WriteLine("{0} - {1}", standardDateTimeFormat, result.Value.ToString(standardDateTimeFormat));
// ReSharper restore PossibleInvalidOperationException
AssertThatToDateTimeResultIsEquivalentToOriginalDateTime(standardDateTimeFormat,
dateTimeAssumption == DateTimeAssumption.AssumeUniversal ? result.Value : result.Value.ToLocalTime(),
dateTime);
}
}
// We cannot use TestCase attribute because arbitraryUniversalDateTime and arbitraryLocalDateTime are not compile time constants.
private static void ToDateTime__ValueIsInAnyStandardDateTimeFormat_CurrentCulture__ReturnsDateTimeOfKindUtc(DateTimeAssumption dateTimeAssumption, DateTime dateTime)
{
foreach (string standardDateTimeFormat in StandardDateTimeFormats.AllStandardDateTimeFormats)
{
DateTime? result = StringConvert.ToDateTime(dateTime.ToString(standardDateTimeFormat), null, CultureInfo.CurrentCulture, dateTimeAssumption);
Assert.That(result.HasValue);
Assert.That(result.Value.Kind, Is.EqualTo(DateTimeKind.Utc));
}
}
// We cannot use TestCase attribute because arbitraryUniversalDateTime, arbitraryLocalDateTime, and arbitraryUnspecifiedDateTime are not compile time constants.
private static void AssertThatForAllStandardDateTimeFormatResultIsAtLeastBestGuessDateTime(DateTimeAssumption dateTimeAssumption, DateTime dateTime)
{
foreach (string standardDateTimeFormat in StandardDateTimeFormats.AllStandardDateTimeFormats)
{
DateTime? result = StringConvert.ToDateTime(dateTime.ToString(standardDateTimeFormat), null, CultureInfo.CurrentCulture, dateTimeAssumption);
Assert.That(result.HasValue);
}
}
/// <inheritdoc cref="ToDateTimeOrNow(Option{string}, Option{string}, Option{IFormatProvider}, DateTimeAssumption)" />
/// <summary>
/// Converts the specified string representation of a date and time to its <see cref="DateTime"/> equivalent using the specified format and culture-specific format information.
/// If the conversion fails, the method returns the current date.
/// </summary>
/// <returns>
/// Date time value equivalent to the <see cref="DateTime"/> contained in the <paramref name="value"/> if the conversion succeeded.
/// <br/>-or-<br/>Current date if the <paramref name="value"/> is None option.
/// <br/>-or-<br/>Current date if the conversion failed.<br/>
/// In case of successful conversion, the returned date time will have <see cref="DateTime.Kind"/> set to <see cref="DateTimeKind.Utc"/>.
/// </returns>
public static DateTime ToDateTimeOrToday(Option<string> value, Option<string> format, Option<IFormatProvider> formatProvider, DateTimeAssumption dateTimeAssumption)
{
return ToDateTime(value, format, formatProvider, dateTimeAssumption).GetValueOrDefault(TimeGenerator.GetToday());
}
#pragma warning restore 1573
/// <summary>
/// Converts the specified string representation of a date and time to its <see cref="DateTime"/> equivalent using the specified format and culture-specific format information.
/// If the conversion fails, the specified default value is returned.
/// </summary>
/// <inheritdoc cref="ToDateTime(Option{string}, Option{string}, Option{IFormatProvider}, DateTimeAssumption)" source="remarks" />
/// <inheritdoc cref="ToInt32(Option{string})" source="param[name='value']"/>
/// <inheritdoc cref="ToDateTime(Option{string}, Option{string})" source="param[name='format']"/>
/// <inheritdoc cref="ToDateTime(Option{string}, Option{string}, Option{IFormatProvider}, DateTimeAssumption)" source="param[name='formatProvider']" />
/// <inheritdoc cref="ToDateTime(Option{string}, Option{string}, Option{IFormatProvider}, DateTimeAssumption)" source="param[name='dateTimeAssumption']" />
/// <inheritdoc cref="ToInt32Or(Option{string}, int)" source="param[name='defaultValue']"/>
/// <returns>
/// Date time value equivalent to the <see cref="DateTime"/> contained in the <paramref name="value"/> if the conversion succeeded.
/// <br/>-or-<br/><paramref name="defaultValue"/> if the <paramref name="value"/> is None option.
/// <br/>-or-<br/><paramref name="defaultValue"/> if the conversion failed.<br/>
/// In case of successful conversion, the returned date time will have <see cref="DateTime.Kind"/> set to <see cref="DateTimeKind.Utc"/>.
/// </returns>
/// <inheritdoc cref="ToDateTime(Option{string})" source="seealso"/>
public static DateTime ToDateTimeOr(Option<string> value, Option<string> format, Option<IFormatProvider> formatProvider, DateTimeAssumption dateTimeAssumption, DateTime defaultValue)
{
return ToDateTime(value, format, formatProvider, dateTimeAssumption).GetValueOrDefault(defaultValue);
}
#pragma warning restore 1573
// TODO-IG: Test with format provider set to invariant culture.
#pragma warning disable 1573 // Parameter does not have XML comment.
/// <summary>
/// Converts the specified string representation of a date and time to its <see cref="DateTime"/> equivalent using the specified format and culture-specific format information.
/// The return value indicates whether the conversion succeeded or failed.
/// </summary>
/// <remarks>
/// <para>
/// If the <paramref name="format"/> is specified (Some) the <paramref name="value"/> must match the specified format exactly.
/// If the <paramref name="format"/> is not specified (None) the method will try to convert the <paramref name="value"/> by using any of the standard .NET date and time format string (see <see cref="StandardDateTimeFormats"/>).
/// </para>
/// <para>
/// If the <paramref name="formatProvider"/> is not specified, the method will use the current thread culture (<see cref="CultureInfo.CurrentCulture"/>) as the format provider.
/// </para>
/// <para>
/// Date and time are returned as a Coordinated Universal Time (UTC).
/// If the <paramref name="value"/> denotes a local time, through a time zone specifier or <see cref="DateTimeAssumption.AssumeLocal"/>,
/// the date and time are converted from the local time to UTC.
/// If the input string denotes a UTC time, through a time zone specifier or <see cref="DateTimeAssumption.AssumeUniversal"/>, no conversion occurs.
/// </para>
/// <para>
/// The <see cref="DateTime.Kind"/> of the returned <see cref="DateTime"/> object is always <see cref="DateTimeKind.Utc"/>.
/// </para>
/// </remarks>
/// <inheritdoc cref="ToInt32(Option{string})" source="param[name='value']"/>
/// <inheritdoc cref="ToDateTime(Option{string}, Option{string})" source="param[name='format']"/>
/// <param name="formatProvider">
/// An object that supplies culture-specific formatting information about the <paramref name="value"/>.
/// If None, the method will use the current thread culture (<see cref="CultureInfo.CurrentCulture"/>).
/// </param>
/// <param name="dateTimeAssumption">An assumption about the date time stored in the <paramref name="value"/>; is it stored as a local or UTC time.</param>
/// <returns>
/// Date time value equivalent to the <see cref="DateTime"/> contained in the <paramref name="value"/> if the conversion succeeded.
/// <br/>-or-<br/>null if the <paramref name="value"/> is None option.
/// <br/>-or-<br/>null if the conversion failed.<br/>
/// In case of successful conversion, the returned date time will have <see cref="DateTime.Kind"/> set to <see cref="DateTimeKind.Utc"/>.
/// </returns>
/// <inheritdoc cref="ToDateTime(Option{string})" source="seealso"/>
public static DateTime? ToDateTime(Option<string> value, Option<string> format, Option<IFormatProvider> formatProvider, DateTimeAssumption dateTimeAssumption)
{
// TODO-IG: Check that dateTimeAssumptio is a valid enumeration value.
// The TryParseExact() fails if the string parameter is null.
// That means we don't need additional check if the value is None.
DateTime result;
return DateTime.TryParseExact(value.ValueOrNull,
format.IsNone ? StandardDateTimeFormats.AllStandardDateTimeFormats : new [] { format.Value },
formatProvider.ValueOr(CultureInfo.CurrentCulture),
DateTimeAssumptionHelper.ToDateTimeStyles(dateTimeAssumption) | DateTimeStyles.AdjustToUniversal,
out result) ? result : (DateTime?)null;
}
