Table of Contents

Class RequiredDateTime<TSelf>

Namespace
Trellis
Assembly
Trellis.Core.dll

Base class for creating strongly-typed DateTime value objects that prevent primitive obsession for dates. Rejects only null by default; MinValue rejection is opt-in via the NotDefaultAttribute attribute. Recommended for any DateTime type used as an EF-mapped property to preserve the database invariant guarantee enforced by TrellisScalarConverter on rehydration.

public abstract class RequiredDateTime<TSelf> : ScalarValueObject<TSelf, DateTime>, IComparable<ValueObject>, IComparable, IEquatable<ValueObject>, IConvertible, IFormattable where TSelf : RequiredDateTime<TSelf>, IScalarValue<TSelf, DateTime>

Type Parameters

TSelf
Inheritance
RequiredDateTime<TSelf>
Implements
Inherited Members
Extension Methods

Examples

Lenient default — only null is rejected:

public partial class EventTimestamp : RequiredDateTime<EventTimestamp> { }

var ok = EventTimestamp.TryCreate(DateTime.UtcNow);              // Success
var min = EventTimestamp.TryCreate(DateTime.MinValue);           // Success (lenient)
var nul = EventTimestamp.TryCreate((DateTime?)null);             // Failure

Strict opt-in — MinValue rejected:

[NotDefault]
public partial class OrderDate : RequiredDateTime<OrderDate> { }

var ok = OrderDate.TryCreate(DateTime.UtcNow);                   // Success
var min = OrderDate.TryCreate(DateTime.MinValue);
// Failure: "Order Date cannot be DateTime.MinValue."

Remarks

This class extends ScalarValueObject<TSelf, T> to provide a specialized base for DateTime-based value objects. When used with the partial keyword, the PrimitiveValueObjectGenerator source generator automatically creates:

  • IScalarValue<TSelf, DateTime> implementation for ASP.NET Core automatic validation
  • TryCreate(DateTime) - Factory method for DateTimes (required by IScalarValue)
  • TryCreate(DateTime?, string?) - Factory method with null validation and custom field name
  • TryCreate(string?, string?) - Factory method for parsing strings with validation
  • IParsable<T> implementation (Parse, TryParse)
  • JSON serialization support via ParsableJsonConverter<T>
  • Explicit cast operator from DateTime
  • OpenTelemetry activity tracing

Validation rules emitted by the source generator:

  • null is always rejected with the per-type "cannot be empty." message.
  • Apply NotDefaultAttribute to additionally reject MinValue with the per-type "cannot be DateTime.MinValue." message. Recommended for any DateTime used as an EF-mapped property to preserve the database invariant guarantee enforced by TrellisScalarConverter on rehydration.

Common use cases:

  • Order dates (OrderDate, ShipDate)
  • Personal dates (BirthDate, HireDate)
  • Scheduling (DueDate, StartDate, EndDate)
  • Any domain concept requiring a non-default DateTime

Constructors

RequiredDateTime(DateTime)

Initializes a new instance of the RequiredDateTime<TSelf> class with the specified DateTime value.

protected RequiredDateTime(DateTime value)

Parameters

value DateTime

The DateTime value.

Methods

ToString()

Returns the DateTime in ISO 8601 round-trip format ("O") using invariant culture. This ensures JSON serialization via ParsableJsonConverter is deterministic, culture-independent, and preserves DateTimeKind (UTC/Local/Unspecified).

public override string ToString()

Returns

string

See Also

ScalarValueObject<TSelf, T>
RequiredInt<TSelf>
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