LSchuster.HL7MessageProcessor 1.0.4

HL7 .Net Message Processor

LSCH.HL7MessageProcessor is a .NET library for parsing and working with HL7 v2.x messages. It provides structured access to message headers and values without mutating the input string, making it suitable for read-only inspection, validation, and routing scenarios.

Features

• 🔍 Deep field access by segment name and component indices
• 🧩 Immutable HL7ReadonlyMessage wrapper
• ✅ HL7-compliant header parsing (MSH segment)
• 🧪 Tested with xUnit and FluentAssertions
• ⚙️ Optimized for performance with ReadOnlySpan<char>

Install via NuGet

dotnet add package LSchuster.HL7MessageProcessor

Or via NuGet Package Manager:

Install-Package LSchuster.HL7MessageProcessor

Quick Start

using LSCH.HL7MessageProcessor;

// Read the HL7 message from a file
var rawMessage = File.ReadAllText("some-message.hl7");
var hl7 = new HL7ReadonlyMessage(rawMessage);

// Access message header data
var sendingApp = hl7.Header.SendingApplication;
var messageDate = hl7.Header.ParsedDateTime;

// Read a specific field
string patientId = hl7.GetValue("PID", 3, 1); // Segment: PID, Field 3, Component 1

// Read a specific field from multiple segments
IReadOnlyList<string> values = hl7.GetValues("OBR", 4, 2); // Segment: OBR, Field 4, Component 2

// Check if the message is structurally valid
bool isValid = hl7.IsValid();

// Check if it's an ACK message
bool isAck = hl7.IsAcknowledgment();
Console.WriteLine($"Is ACK? {isAck}");

// Generate an acknowledgment
if (!isAck && isValid)
{
    var ack = hl7.GenerateAcknowledgement(
        switchSenderAndReceiver: true,
        acknowledgmentCode: "CR", // "CA" for success, "AE"/"AR"/"CR"/"CE" for errors
        errorMessage: "Missing required field: PID-5"
    );

    string ackRaw = ack.ToString();
    Console.WriteLine("Generated ACK:\n" + ackRaw);
}

Testing

The library includes a dedicated xUnit test project that uses real HL7 sample messages. Tests verify structural parsing, header field correctness, and field access methods.

Run tests locally:

dotnet test

Project Structure

src/
  HL7MessageProcessor/             # Library project
test/
  HL7MessageProcessor.Tests/      # xUnit test project
  └── TestData/                   # Contains sample .hl7 files

License

This project is licensed under the MIT License.

Links

• NuGet Package
• GitHub Repository

Author

GitHub @LSchuster