HL7

 // First, import classes from the library as needed...
use Aranyasen  HL7 ; // HL7 factory class
use Aranyasen  HL7  Message ; // If Message is used
use Aranyasen  HL7  Segment ; // If Segment is used
use Aranyasen  HL7  Segments  MSH ; // If MSH is used
// ... and so on

 // Create a Message object from a HL7 string
$ message = HL7 :: from ( " MSH|^~ \ &|1| " )-> createMessage (); // Returns Message object

// Or, using Message class...
$ message = new Message ( " MSH|^~ \ &|1| r PID|||abcd| r" ); // Either n or r can be used as segment endings

// 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 = new Message ();
$ message -> isempty (); // Returns true

 // 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 ()-> createMessage (); // Creates an empty message

// The HL7 factory class provides methods that can be chained together in a fluent fashion
$ message = HL7 :: build ()
    -> withComponentSeparator ( ' # ' )
    -> withFieldSeparator ( ' - ' )
    -> createMessage ();

// Or, using Message class...
$ message = new Message ();

 // When a message is composed using Message class, there are multiple parameters available to define the properties of the HL7 .
// Note: All of these properties are available as fluent methods in HL7 factory class (shown above). So it's recommended to use that for readability

// Creating multiple message objects may have an unexpected side effect: segments start with wrong index values (Check tests/MessageTest for explanation)...
// Use 4th argument as true, or call resetSegmentIndices() on $message object to reset segment indices to 1
$ message = new Message ( " MSH|^~&|||||||ORM^O01||P|2.3.1| " , null , true , true );
// ... 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
// Use 5th argument as false...
$ HL7 String = " MSH|^~&|||||||ORU^R01|00001|P|2.3.1| n" . " OBX|1||11^AA| n" . " OBX|1||22^BB| n" ;
$ message = new Message ( $ HL7 String , null , true , true , false ); $ // $message contains both OBXs with given indexes in the string 

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

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

// Create a custom 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 -> setSegment ( $ 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
$ 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 ();

 $ ip = ' 127.0.0.1 ' ; // An IP
$ port = ' 12001 ' ; // And Port where a HL7 listener is listening
$ message = new Message ( $ HL7 String ); // Create a Message object from your HL7 string

// 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 = ( new Connection ( $ ip , $ port ))-> send ( $ message ); // Send a HL7 to remote listener
$ returnString = $ ack -> toString ( true );
if ( strpos ( $ 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 ();
}

 $ msg = new Message ( " MSH|^~ \ &|1| r ABC|1||^AAAA1^^^BB| " , null , true );
$ ackResponse = new ACK ( $ msg );

 $ msg = new Message ( " MSH|^~ \ &|1| r ABC|1||^AAAA1^^^BB| " , null , true );
$ ackResponse = new ACK ( $ msg , null , [ ' SEGMENT_SEPARATOR ' => ' rn ' , ' HL7 _VERSION ' => ' 2.5 ' ]);

    $ 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