HlSegment

HlSegment models the X12 HL hierarchical level segment, used throughout 837 claim transactions to establish parent/child loop relationships (e.g. billing provider → subscriber → patient). Its child-level indicator can be supplied either as an explicit code or derived from a boolean flag, and Fill() recomputes that flag strictly from whether the code equals "1" (BR-052).

Purpose

• Represents the HL segment identity via SegmentId returning the literal "HL" (BR-020).
• Carries IdNumber and ParentIdNumber establishing this level's position in the hierarchy, plus LevelCode classifying the level's loop type.
• Reports whether the level has children via element 4: an explicit ChildCode when supplied, otherwise "1"/"0" derived from ChildExists (BR-052).
• On Fill(), sets ChildExists to true only when the parsed ChildCode equals "1" (BR-052).

Context

• Namespace: SAIF.Common.Files.Edi.Segments
• Assembly/package: SAIF.Framework.Common.Files

Public members

Member	Signature	Purpose
SegmentId	string SegmentId { get; }	Returns the literal X12 segment identifier "HL".
IdNumber	int IdNumber { get; set; }	This hierarchical level's own identifier (HL01), element 1.
ParentIdNumber	int? ParentIdNumber { get; set; }	The identifier of this level's parent in the hierarchy (HL02), element 2.
LevelCode	string LevelCode { get; set; }	The code classifying this level's loop type (HL03), element 3.
ChildCode	string ChildCode { get; set; }	An explicit child-level indicator string (HL04); when set, takes precedence over ChildExists on Build() (BR-052).
ChildExists	bool? ChildExists { get; set; }	Whether this level has child levels; used to derive "1"/"0" for element 4 when ChildCode is null, and recomputed on Fill() as ChildCode == "1" (BR-052).
Build	IEdiSegment Build()	Creates a SegmentBuilder("HL"), adds IdNumber, ParentIdNumber, and LevelCode at elements 1-3, then adds element 4 as ChildCode if set, else as "1"/"0" from ChildExists if set, else omits it, returning the built segment (BR-052).
Fill	void Fill(IEdiSegment segment)	Parses elements 1-2 as int via int.TryParse, reads LevelCode and ChildCode at elements 3-4, and sets ChildExists to (ChildCode == "1") (BR-052).
Parse	static HlSegment Parse(IEdiSegment segment)	Instantiates a new HlSegment, calls Fill(segment) on it, and returns it.

Behavioral notes

• Fill() sets ChildExists to false (not null) whenever ChildCode is anything other than "1", including when the segment carries no element 4 at all, since GetChildValue returns an empty string rather than null in that case*.

Note: Statements marked with * were inferred from code structure, naming conventions, or contextual evidence where direct confirmation was not available in source artifacts.

Sources

• Common\SAIF.Common.Files\Edi\Segments\HlSegment.cs