---
title: IEdiSegment
summary: API reference for IEdiSegment.
status: draft
owner: SAIF Doc Gen
last_reviewed: 2026-09-15
library: SAIF.Framework.Common.Files
reference_type: package
---

# IEdiSegment

`IEdiSegment` is the contract implemented by `EdiSegment`; it extends `IEdiDataElement` with the additional surface needed to expose a segment's identifier and its own child data elements.

## Purpose
- Declares `SegmentId`, `DataElements`, `GetElement`, `GetCompositeElement`, and `GetChildValue` as the contract any segment implementation must provide, letting parser/builder code depend on the segment abstraction rather than the concrete `EdiSegment` class.

## Context
- Namespace: `SAIF.Common.Files.Edi`
- Assembly/package: `SAIF.Framework.Common.Files`
- Extends: `IEdiDataElement`

## Public members
| Member | Signature | Purpose |
| --- | --- | --- |
| SegmentId | `string SegmentId { get; set; }` | The X12 segment tag (e.g. `"ISA"`, `"GS"`, `"ST"`) identifying the segment's type ([BR-020](../../business-rules.md#br-020-first-element-is-the-segment-identifier)). |
| DataElements | `IEnumerable<IEdiDataElement> DataElements { get; }` | The ordered collection of data elements that make up this segment. |
| GetElement | `IEdiDataElement GetElement(int index)` | Returns the data element at the given ordinal `index`, or `null` if none exists. |
| GetCompositeElement | `IEdiCompositeDataElement GetCompositeElement(int index)` | Returns the element at `index` as a composite data element, re-parsing it if necessary. |
| GetChildValue | `string GetChildValue(int index)` | Returns the raw text `Value` of the element at `index`, or `string.Empty` if none exists. |

## Inherited public members

Members in this section are inherited from `IEdiDataElement` (and, transitively, `IEdiElement`) in `SAIF.Framework.Common.Files`. They are available on this type through inheritance.

| Member | Signature | Purpose | Origin |
| --- | --- | --- | --- |
| Index | `int Index { get; set; }` | The segment's ordinal position within its parent file's flat segment list. | `SAIF.Framework.Common.Files` — `IEdiElement` |
| Value | `string Value { get; set; }` | The raw text value of the segment as a whole element. | `SAIF.Framework.Common.Files` — `IEdiElement` |
| Type | `ElementType Type { get; }` | Identifies the concrete element kind (`ElementType.Segment` for conforming implementations). | `SAIF.Framework.Common.Files` — `IEdiElement` |

## Sources
- Common\SAIF.Common.Files\Edi\IEdiSegment.cs