HL7-dotnetcore
This is a fork from Jayant Singh's HL7 parser. Since then, it has been modified fundamentally, with respect to features, code quality, bugs and typos. For more information about the original implementation read:
The field encoding and decoding methods have been based on https://github.com/elomagic/hl7inspector
Object construction
Create a Message object and pass raw HL7 message in text format
Message message = new Message(strMsg);
// Parse this message
bool isParsed = false;
try
{
isParsed = message.ParseMessage();
}
catch(Exception ex)
{
// Handle the exception
}Adding a message header
For adding a header segment to a new message object, use the AddSegmentMSH() method, after constructing an empty message:
message.AddSegmentMSH(sendingApplication, sendingFacility,
receivingApplication, receivingFacility,
security, messageType,
messageControlId, processingId, version);Message extraction
If the HL7 message is coming from a MLLP connection (see the official documentation), the message needs to be cleared from the MLLP prefixes and suffixes. Also, consider there can be more than one message in a single MLLP frame.
For this purpose, there is an ExtractMessages() method, to be used as follows:
// extract the messages from a buffer containing a MLLP frame
var messages = MessageHelper.ExtractMessages(buffer);
// construct and process each message
foreach (var strMsg in messages)
{
Message message = new Message(strMsg);
// do something with the message object
}Accessing Segments
Get list of all segments
List<Segment> segList = message.Segments();Get List of list of repeated segments by name
For example if there are multiple IN1 segments
List<Segment> IN1List = message.Segments("IN1");Access a particular occurrence from multiple IN1s providing the index
Note index 1 will return the 2nd element from list
Segment IN1_2 = message.Segments("IN1")[1];Get count of IN1s
int countIN1 = message.Segments("IN1").Count;Access first occurrence of any segment
Segment IN1 = message.DefaultSegment("IN1");
// OR
Segment IN1 = message.Segments("IN1")[0];Accessing Fields
Access field values
string SendingFacility = message.getValue("MSH.4");
// OR
string SendingFacility = message.DefaultSegment("MSH").Fields(4).Value;
// OR
string SendingFacility = message.Segments("MSH")[0].Fields(4).Value;Check if field is componentized
bool isComponentized = message.Segments("PID")[0].Fields(5).IsComponentized;
// OR
bool isComponentized = message.IsComponentized("PID.5");Check if field has repetitions
bool isRepeated = message.Segments("PID")[0].Fields(3).HasRepetitions;
// OR
bool isRepeated = message.HasRepetitions("PID.3");Get list of repeated fields
List<Field> repList = message.Segments("PID")[0].Fields(3).Repetitions();Get particular repetition i.e 2nd repetition of PID.3
Field PID3_R2 = message.Segments("PID")[0].Fields(3).Repetitions(2);Update value of any field i.e. to update PV1.2 – patient class
message.setValue("PV1.2", "I");
// OR
message.Segments("PV1")[0].Fields(2).Value = "I";Access some of the required MSH fields with properties
string version = message.Version;
string msgControlID = message.MessageControlID;
string messageStructure = message.MessageStructure;Accessing Components
Access particular component i.e. PID.5.1 – Patient Family Name
string PatName1 = message.getValue("PID.5.1");
// OR
string PatName1 = message.Segments("PID")[0].Fields(5).Components(1).Value;Check if component is sub componentized
bool isSubComponentized = message.Segments("PV1")[0].Fields(7).Components(1).IsSubComponentized;
// OR
bool isSubComponentized = message.IsSubComponentized("PV1.7.1");Update value of any component
message.Segments("PID")[0].Fields(5).Components(1).Value = "Jayant";
// OR
message.setValue("PID.5.1", "Jayant");Adding new Segment
//Create a Segment with name ZIB
Segment newSeg = new Segment("ZIB");
// Create Field ZIB_1
Field ZIB_1 = new Field("ZIB1");
// Create Field ZIB_5
Field ZIB_5 = new Field("ZIB5");
// Create Component ZIB.5.2
Component com1 = new Component("ZIB.5.2");
// Add Component ZIB.5.2 to Field ZIB_5
// 2nd parameter here specifies the component position, for inserting segment on particular position
// If we don’t provide 2nd parameter, component will be inserted to next position (if field has 2 components this will be 3rd,
// If field is empty this will be 1st component
ZIB_5.AddNewComponent(com1, 2);
// Add Field ZIB_1 to segment ZIB, this will add a new filed to next field location, in this case first field
newSeg.AddNewField(ZIB_1);
// Add Field ZIB_5 to segment ZIB, this will add a new filed as 5th field of segment
newSeg.AddNewField(ZIB_5, 5);
// Add segment ZIB to message
message.AddNewSegment(newSeg);New Segment would look like this:
ZIB|ZIB1||||ZIB5^ZIB.5.2
After evaluated and modified required values, the message can be obtained again in text format
string strUpdatedMsg = message.SerializeMessage();Encoded segments
Some contents may contain forbidden characters like pipes and ampersands. Whenever there is a possibility of having those characters, the content shall be encoded before calling the 'AddNew' methods, like in the following code:
var obx = new Segment("OBX", new HL7Encoding());
// Not encoded. Will be split into parts.
obx.AddNewField("70030^Radiologic Exam, Eye, Detection, FB^CDIRadCodes");
// Encoded. Won't be parsed nor split.
obx.AddNewField(obx.Encoding.Encode("domain.com/resource.html?Action=1&ID=2")); Copying a segment
The DeepCopy method allows to perform a clone of a segment when building new messages. Countersense, if a segment is referenced directly when adding segments to a message, a change in the segment will affect both the origin and new messages.
Segment pid = ormMessage.DefaultSegment("PID").DeepCopy();
oru.AddNewSegment(pid);Generate ACKs
To generate an ACK message
Message ack = message.getACK();To generate negative ACK (NACK) message with error message
Message nack = message.getNACK("AR", "Invalid Processing ID");It may be required to change the application and facility fields
Message ack = message.getACK();
ack.setValue("MSH.3", myHL7AppName);
ack.setValue("MSH.4", myHL7Facility);