DP44/enriched-qwen3-coder-next/Common/DTS.Common.Serialization/IRIGCH10/Attributes.md

source_files, generated_at, model, schema_version, sha256

source_files	generated_at	model	schema_version	sha256
Common/DTS.Common.Serialization/IRIGCH10/Attributes/DescriptionDecoder.cs Common/DTS.Common.Serialization/IRIGCH10/Attributes/PacketHeaderValueAttribute.cs Common/DTS.Common.Serialization/IRIGCH10/Attributes/DataTypeVersionValueAttribute.cs	2026-04-16T03:43:04.052592+00:00	Qwen/Qwen3-Coder-Next-FP8	1	32d5e734af040685

IRIG CH10 Attribute Decoders Documentation

1. Purpose

This module provides utility classes for extracting metadata annotations from .NET enum values, specifically tailored for IRIG CH10 data format compliance. It enables serialization logic to retrieve human-readable descriptions, maximum length constraints, packet header values, and data type version numbers associated with enum fields via custom attributes (DescriptionAttribute, MaxLengthAttribute, PacketHeaderValueAttribute, DataTypeVersionValueAttribute). These utilities bridge the gap between strongly-typed enum definitions and the string/byte-level requirements of the IRIG CH10 specification (e.g., TMATS file generation, packet header construction).

2. Public Interface

DescriptionDecoder.GetDescription(Enum value)

• Signature: public static string GetDescription(Enum value)
• Behavior: Returns the DescriptionAttribute.Description value attached to the enum field corresponding to value. If no such attribute exists, returns the enum's ToString() representation.

MaxLengthDecoder.GetMaxLength(Enum value)

• Signature: public static int GetMaxLength(Enum value)
• Behavior: Returns the Length property of the MaxLengthAttribute attached to the enum field corresponding to value. If no such attribute exists, returns 0.

PacketHeaderValueAttribute.GetPacketHeaderValue(Enum value)

• Signature: public static byte GetPacketHeaderValue(Enum value)
• Behavior: Returns the PacketHeaderValue property of the PacketHeaderValueAttribute attached to the enum field corresponding to value. If no such attribute exists, returns Default.PacketHeaderValue (which is 0x00).

DataTypeVersionValueAttribute.GetDataTypeVersionValue(Enum value)

• Signature: public static byte GetDataTypeVersionValue(Enum value)
• Behavior: Returns the DataTypeVersionValue property of the DataTypeVersionValueAttribute attached to the enum field corresponding to value. If no such attribute exists, returns Default.DataTypeVersionValue (which is 0x00).

Note

: The static methods GetPacketHeaderValue and GetDataTypeVersionValue are instance methods on their respective attribute classes, not static methods on the class itself. They are called on the attribute class (e.g., PacketHeaderValueAttribute.GetPacketHeaderValue(someEnum)) and operate on the enum value passed.

3. Invariants

• Enum Field Resolution: All decoder methods assume the Enum value corresponds to a valid field name in its declaring type (via value.ToString() → GetField()). If the enum value is invalid or the field name resolution fails (e.g., due to compiler-generated names or custom ToString() overrides), behavior is undefined (likely throws NullReferenceException or returns incorrect data).
• Attribute Uniqueness: Methods return the first attribute found via GetCustomAttributes(...). If multiple attributes of the same type exist on a single field, only the first is used.
• Default Values: When no attribute is present:
  • GetDescription falls back to value.ToString()
  • GetMaxLength returns 0
  • GetPacketHeaderValue returns 0x00
  • GetDataTypeVersionValue returns 0x00
• Attribute Scope: PacketHeaderValueAttribute and DataTypeVersionValueAttribute are decorated with [AttributeUsage(AttributeTargets.All)], meaning they can be applied to any program element (not just enums), though the decoders assume usage on enum fields.

4. Dependencies

Dependencies of this module:

• System.ComponentModel: For DescriptionAttribute
• System.ComponentModel.DataAnnotations: For MaxLengthAttribute
• System.Linq: For Any() and First() LINQ methods
• System.Reflection: For GetType(), GetField(), GetCustomAttributes()

Dependencies on this module:

• Other IRIG CH10 serialization components (not visible in source) that rely on these decoders to:
  • Generate TMATS string descriptions from enums
  • Enforce or suggest max-length constraints for string fields
  • Construct packet headers (e.g., for packet type/version identification)
  • Serialize data type version information per CH10 spec

5. Gotchas

• No null-safety: All methods call value.ToString() and GetField(...) without validating that value is non-null or that the field exists. Passing null or an invalid enum value will cause a NullReferenceException.
• Case sensitivity: value.ToString() is used directly for GetField(). If the enum field name differs in casing (e.g., due to compiler optimizations or custom ToString() overrides), field resolution may fail.
• MaxLengthAttribute is advisory only: As noted in the MaxLengthDecoder summary, CH10 specifies max lengths as suggestions, not hard requirements. Consumers should not assume enforcement.
• Default attribute behavior: The Default static fields (PacketHeaderValueAttribute.Default, DataTypeVersionValueAttribute.Default) are new instances with 0x00 values—not singleton references to a shared default. This is safe but worth noting for equality comparisons.
• No validation of attribute targets: While PacketHeaderValueAttribute and DataTypeVersionValueAttribute allow AttributeTargets.All, their static Get*Value methods assume usage on enum fields. Applying them to non-enum members (e.g., classes, methods) will likely cause runtime errors.
• No support for inherited attributes: GetCustomAttributes(..., false) excludes inherited attributes. If attributes are defined on base enum values (in inheritance hierarchies), they will be ignored.

None identified from source alone beyond those above.