var Reader = require('hl7js').Reader;
var reader = new Reader();

/// Basic Parsing
var reader = new Reader('BASIC');
fs.readFile(hl7_file_path, function (err, buffer) {

    reader.read(buffer.toString(), function (err, hl7Data) {
        console.log(err);
        console.log(hl7Data);
    });
});

fs.readFile(hl7_file_path, function (err, buffer) {

    reader.read(buffer.toString(), 'MSH PID [{OBR {OBX}}]', function (err, hl7Data, hl7Json) {
            console.log(err);

            if (!err) {
                var patientName = hl7Json['PID'][5]; /// Similar pattern: hl7Json['PID'].fields[5].value ==> For advanced usage
                console.log('ORU->Patient name: ', patientName);
            }
    });
});

var messageType = hl7Data.mshSegment.messageType;

var patientName = hl7Json['PID'][5];
/// (or)
var patientName = hl7Json['PID'].fields[5].value;

var Writer = require('hl7js').Writer;

/// Initializing writer with default delimiters
var writer = new Writer();
/// Initializing writer with user defined delimiters
var writer = new Writer({
    lineSeparator: '0xD 0xA',
    framePrefix: '',
    frameSuffix: '',
    fieldSeparater: '|',
    componentSeparater: '^',
    fieldRepeatSeparater: '~',
    escapeCharacter: '\\',
    subComponentSeparater: '&'
});

writer.addHeader({
    sendingApplication: 's_app',
    sendingFacility: 'a_facility',
    receivingApplication: 'r_app',
    receivingFacility: 'r_facility',
    dateTimeOfMessage: 'dt',
    security: '',
    messageType: 'ADT^A01',
    messageControlId: '123',
    processingId: '',
    versionId: '2.5',
    sequenceNo: '',
    continuationPointer: '',
    acceptAckType: '',
    applicationAckType: '',
    countryCode: '',
    characterSet: '',
    messageLanguage: ''
});

writer.addSegment('PID', ['name', 1, 2, ['lname', 'fname'], 'eee']);
writer.addSegment('IN1', ['1']);
writer.addSegment('IN2');

var hl7Text = writer.toString();
console.log(hl7Text);