Release announcement:

Version 4.0 (Breaking Release)

⚠️ This release contains breaking changes. If you are upgrading from 3.x, please read the Guide before upgrading.

Key Changes

• Minimum supported PHP version is now 8.2
• Message must start with a MSH segment
• InvalidArgumentException replaced with HL7Exception
• new Message() is now deprecated (use HL7 factory instead)
• setSegment() is deprecated (use insertSegment() instead)
• In insertSegment() method, only MSH can be inserted now in the 0th index
• withSegmentSeparator() in HL7 factory accepts CRLF (\r\n) as argument. Any other multi-character separator will continue to throw exception

If something breaks after upgrading:

• Report bugs or request features at Issues
• Submit fixes at Pull Requests

---

Important

• The global setting SEGMENT_ENDING_BAR is deprecated and will be removed in a future release. If you're using this in your code, replace it with WITH_SEGMENT_ENDING_FIELD_SEPARATOR

PHP Compatibility

PHP Version	Package Version
8.2+	4.x
8.0 – 8.1	3.2.2
7.4	2.1.7
7.2	2.0.2
7.0 – 7.1	1.5.4

Introduction

This is a PHP package to create, parse and send HL7 v2 messages. This was originally inspired from Net-HL7 Perl package.

Installation

composer require aranyasen/hl7

Usage

Parsing

// Create a Message object from a HL7 string
use Aranyasen\HL7;
$message = HL7::from("MSH|^~\\&|1|")->create();
$message = HL7::from("MSH|^~\\&|1|\rPID|||abcd|\r")->create(); // Creates Message object with two segments with \r as segment ending (\n can also be used)

// Get string form of the message
echo $message->toString(true);

// Extracting segments and fields from a Message object...
$message->getSegmentByIndex(1); // Get the first segment
$message->getSegmentsByName('ABC'); // Get an array of all 'ABC' segments
$message->getFirstSegmentInstance('ABC'); // Returns the first ABC segment. Same as $message->getSegmentsByName('ABC')[0];

// Check if a segment is present in the message object
$message->hasSegment('ABC'); // return true or false based on whether PID is present in the $message object

// Check if a message is empty
$message = HL7::build()->create();
$message->removeSegmentsByName('MSH')
$message->isEmpty(); // Returns true

Composing new messages

// The class `HL7` can be used to build HL7 object. It is a factory class with various helper methods to help build a hl7.
$message = HL7::build()->create(); // Creates a Message containing MSH segment with default separators, version etc.

Configuring HL7 messages

// The HL7 factory class provides methods that can be chained together in a fluent fashion. These can be used to
// override the defaults
$message = HL7::build()
    ->withComponentSeparator('#') // Use # as the component separator instead of the default ^ 
    ->withFieldSeparator('-') // Use - as the field separator instead of the default |
    ->withSegmentSeparator('\r\n') // Override segment separator
    ->withHL7Version('2.3') // Use HL7 version 2.3
    ->create();

// Creating multiple message objects may have an unexpected side effect: segments start with wrong index values (Check tests/MessageTest for explanation)...
// So to reset segment indices to 1:
HL7::from("MSH|^~\&|||||||ORM^O01||P|2.3.1|")->resetIndices()->create(); // Use resetIndices() while creating a new message
$message->resetSegmentIndices(); // or call resetSegmentIndices() on an existing $message object
// ... any segments added here will now start index from 1, as expected.

// Sometimes you may want to have exact index values, rather than auto-incrementing for each instance of a segment
$hl7String = "MSH|^~\&|||||||ORU^R01|00001|P|2.3.1|\n" . "OBX|1||11^AA|\n" . "OBX|1||22^BB|\n";
$message = HL7::from($hl7String)
    ->autoIncrementIndices(false)
    ->create();
// $message now contains both OBXs with 1 as the index, instead of 1 and 2

// Ensure empty sub-fields are not removed
// Note: We should perhaps _always_ use this while creating a message object, as we don't want empty subfields removed. In future versions, this will be the default
$message = HL7::from("MSH|^~\\&|1|\rPV1|1|O|^AAAA1^^^BB|")->keepEmptySubfields()->create();
$pv1 = $message->getSegmentByIndex(1);
$fields = $pv1->getField(3); // $fields is ['', 'AAAA1', '', '', 'BB']

// Create/send message with segment-ending field-separator character (default "|") removed
use Aranyasen\HL7\Message;
$message = new Message("MSH|^~\\&|1|\nABC|||xxx\n", ['WITH_SEGMENT_ENDING_FIELD_SEPARATOR' => false]);
$message->toString(true); // Returns "MSH|^~\&|1\nABC|||xxx\n"
(new Connection($ip, $port))->send($message); // Sends the message without ending field-separator character (details on Connection below)

// Segment with separator character (~) creates sub-arrays containing each sub-segment
$message = HL7::from("MSH|^~\&|||||||ADT^A01||P|2.3.1|\nPID|||3^0~4^1")->create(); // Creates [[3,0], [4,1]]

// To create a single array instead, use doNotSplitRepetition()
// Note: Since this leads to a non-standard behavior, it may be removed in future
$message = HL7::from("MSH|^~\&|||||||ADT^A01||P|2.3.1|\nPID|||3^0~4^1")
    ->doNotSplitRepetition()
    ->create(); // Creates ['3', '0~4', '1']

Handling segments and fields

// Once a message object is created, we can now add, insert, set segments and fields.

// Create a MSH segment and add to message object
use Aranyasen\HL7\Segments\MSH;
$msh = new MSH();
$message->addSegment($msh); // Message is: "MSH|^~\&|||||20171116140058|||2017111614005840157||2.3|\n"

// Create a custom segment
use Aranyasen\HL7\Segment;
$abc = new Segment('ABC');
$abc->setField(1, 'xyz');
$abc->setField(2, 0);
$abc->setField(4, ['']); // Set an empty field at 4th position. 2nd and 3rd positions will be automatically set to empty
$abc->clearField(2); // Clear the value from field 2
$message->insertSegment($abc, 1); // Message is now: "MSH|^~\&|||||20171116140058|||2017111614005840157||2.3|\nABC|xyz|\n"

// Create a defined segment (To know which segments are defined in this package, look into Segments/ directory)
// Advantages of defined segments over custom ones (shown above) are 1) Helpful setter methods, 2) Auto-incrementing segment index
use Aranyasen\HL7\Segments\PID;
$pid = new PID(); // Automatically creates PID segment, and adds segment index at PID.1
$pid->setPatientName([$lastname, $firstname, $middlename, $suffix]); // Use a setter method to add patient's name at standard position (PID.5)
$pid->setField('abcd', 5); // Apart from standard setter methods, you can manually set a value at any position too
unset($pid); // Destroy the segment and decrement the id number. Useful when you want to discard a segment.

// It is possible that segments get added in a way that the Set IDs/Sequence IDs within the message are not in order or leave gaps. To reset all Set/Sequence IDs in the message:

$message->reindexSegments();

Send messages to remote listeners

Side note: In order to run Connection you need to install PHP ext-sockets https://www.php.net/manual/en/sockets.installation.php

$ip = '127.0.0.1'; // An IP
$port = '12001'; // And Port where a HL7 listener is listening
$message = HL7::from($hl7String)->create(); // Create a Message object from your HL7 string. See above for details

// Create a Socket and get ready to send message. Optionally add timeout in seconds as 3rd argument (default: 10 sec)
$connection = new Connection($ip, $port);
$response = $connection->send($message); // Send to the listener, and get a response back
echo $response->toString(true); // Prints ACK from the listener

ACK

Handle ACK message returned from a remote HL7 listener...

use Aranyasen\HL7\Connection;
$ack = (new Connection($ip, $port))->send($message); // Send a HL7 to remote listener
$returnString = $ack->toString(true);
if (str_contains($returnString, 'MSH') === false) {
    echo "Failed to send HL7 to 'IP' => $ip, 'Port' => $port";
}
$msa = $ack->getFirstSegmentInstance('MSA');
$ackCode = $msa->getAcknowledgementCode();
if ($ackCode[1] === 'A') {
    echo "Received ACK from remote\n";
}
else {
    echo "Received NACK from remote\n";
    echo "Error text: " . $msa->getTextMessage();
}

Create an ACK response from a given HL7 message:

use Aranyasen\HL7\Messages\ACK;
$msg = HL7::from("MSH|^~\\&|1|\rABC|1||^AAAA1^^^BB|")->keepEmptySubfields()->create();
$ackResponse = new ACK($msg);

Options can be passed while creating ACK object:

$msg = HL7::from("MSH|^~\\&|1|\rABC|1||^AAAA1^^^BB|")->keepEmptySubfields()->create();
$ackResponse = new ACK($msg, null, ['SEGMENT_SEPARATOR' => '\r\n', 'HL7_VERSION' => '2.5']);

APIs

This package exposes a number of public methods for convenient HL7 handling. Some examples are:

1. Considering you have a Message object (say, $msg = new Message(file_get_contents('somefile.hl7'));)

    $msg->toFile('/path/to/some.hl7'); // Write to a file
    $msg->isOru(); // Check if it's an ORU
    $msg->isOrm(); // Check if it's an ORM

Visit docs\README for details on available APIs

All segment level getter/setter APIs can be used in two ways -

• If a position index isn't provided as argument (1st argument for getters, 2nd for setters), a standard index is used. $pid->setPatientName('John Doe') -> Set patient name at position 5 as per HL7 v2.3 standard $pid->getPatientAddress() -> Get patient address from standard 11th position

• To use a custom position index, provide it in the argument: $pid->setPatientName('John Doe', 6) -> Set patient name at 6th position in PID segment $pid->getPatientAddress(12) -> Get patient address from 12th position

Issues

Bug reports and feature requests can be submitted on the Github Issue Tracker.

Contributing

See CONTRIBUTING.md for information.