Source code for camcops_server.cc_modules.cc_hl7

#!/usr/bin/env python

# noinspection HttpUrlsUsage
"""
camcops_server/cc_modules/cc_hl7.py

===============================================================================

    Copyright (C) 2012, University of Cambridge, Department of Psychiatry.
    Created by Rudolf Cardinal (rnc1001@cam.ac.uk).

    This file is part of CamCOPS.

    CamCOPS is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    CamCOPS is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with CamCOPS. If not, see <https://www.gnu.org/licenses/>.

===============================================================================

**Core HL7 functions, e.g. to build HL7 v2 messages.**

General HL7 sources:

- https://python-hl7.readthedocs.org/en/latest/
- http://www.interfaceware.com/manual/v3gen_python_library_details.html
- http://www.interfaceware.com/hl7_video_vault.html#how
- http://www.interfaceware.com/hl7-standard/hl7-segments.html
- https://www.hl7.org/special/committees/vocab/v26_appendix_a.pdf
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC130066/

To consider

- batched messages (HL7 batching protocol);
  https://docs.oracle.com/cd/E23943_01/user.1111/e23486/app_hl7batching.htm
- note: DG1 segment = diagnosis

Basic HL7 message structure:

- can package into HL7 2.X message as encapsulated PDF;
  https://www.hl7standards.com/blog/2007/11/27/pdf-attachment-in-hl7-message/
- message ORU^R01
  https://www.corepointhealth.com/resource-center/hl7-resources/hl7-messages
- MESSAGES: http://www.interfaceware.com/hl7-standard/hl7-messages.html
- OBX segment = observation/result segment;
  https://www.corepointhealth.com/resource-center/hl7-resources/hl7-obx-segment;
  http://www.interfaceware.com/hl7-standard/hl7-segment-OBX.html
- SEGMENTS:
  https://www.corepointhealth.com/resource-center/hl7-resources/hl7-segments
- ED field (= encapsulated data);
  http://www.interfaceware.com/hl7-standard/hl7-fields.html
- base-64 encoding

We can then add an option for structure (XML), HTML, PDF export.

"""

import base64
import logging
import socket
from typing import List, Optional, Tuple, TYPE_CHECKING, Union

from cardinal_pythonlib.datetimefunc import format_datetime
from cardinal_pythonlib.logs import BraceStyleAdapter
import hl7
from pendulum import Date, DateTime as Pendulum

from camcops_server.cc_modules.cc_constants import DateFormat, FileType
from camcops_server.cc_modules.cc_simpleobjects import HL7PatientIdentifier

if TYPE_CHECKING:
    from camcops_server.cc_modules.cc_request import CamcopsRequest
    from camcops_server.cc_modules.cc_simpleobjects import TaskExportOptions
    from camcops_server.cc_modules.cc_task import Task

log = BraceStyleAdapter(logging.getLogger(__name__))


# =============================================================================
# Constants
# =============================================================================

# STRUCTURE OF HL7 MESSAGES
# MESSAGE = list of segments, separated by carriage returns
SEGMENT_SEPARATOR = "\r"
# SEGMENT = list of fields (= composites), separated by pipes
FIELD_SEPARATOR = "|"
# FIELD (= COMPOSITE) = string, or list of components separated by carets
COMPONENT_SEPARATOR = "^"
# Component = string, or lists of subcomponents separated by ampersands
SUBCOMPONENT_SEPARATOR = "&"
# Subcomponents must be primitive data types (i.e. strings).
# ... http://www.interfaceware.com/blog/hl7-composites/

REPETITION_SEPARATOR = "~"
ESCAPE_CHARACTER = "\\"

# Fields are specified in terms of DATA TYPES:
# http://www.corepointhealth.com/resource-center/hl7-resources/hl7-data-types

# Some of those are COMPOSITE TYPES:
# http://amisha.pragmaticdata.com/~gunther/oldhtml/composites.html#COMPOSITES


# =============================================================================
# HL7 helper functions
# =============================================================================


[docs]def get_mod11_checkdigit(strnum: str) -> str: # noinspection HttpUrlsUsage """ Input: string containing integer. Output: MOD11 check digit (string). See: - http://www.mexi.be/documents/hl7/ch200025.htm - https://stackoverflow.com/questions/7006109 - http://www.pgrocer.net/Cis51/mod11.html """ total = 0 multiplier = 2 # 2 for units digit, increases to 7, then resets to 2 try: for i in reversed(range(len(strnum))): total += int(strnum[i]) * multiplier multiplier += 1 if multiplier == 8: multiplier = 2 c = str(11 - (total % 11)) if c == "11": c = "0" elif c == "10": c = "X" return c except (TypeError, ValueError): # garbage in... return ""
[docs]def make_msh_segment( message_datetime: Pendulum, message_control_id: str ) -> hl7.Segment: """ Creates an HL7 message header (MSH) segment. - MSH: https://www.hl7.org/documentcenter/public/wg/conf/HL7MSH.htm - We're making an ORU^R01 message = unsolicited result. - ORU = Observational Report - Unsolicited - ORU^R01 = Unsolicited transmission of an observation message - https://www.corepointhealth.com/resource-center/hl7-resources/hl7-oru-message - https://www.hl7kit.com/joomla/index.php/hl7resources/examples/107-orur01 """ # noqa segment_id = "MSH" encoding_characters = ( COMPONENT_SEPARATOR + REPETITION_SEPARATOR + ESCAPE_CHARACTER + SUBCOMPONENT_SEPARATOR ) sending_application = "CamCOPS" sending_facility = "" receiving_application = "" receiving_facility = "" date_time_of_message = format_datetime( message_datetime, DateFormat.HL7_DATETIME ) security = "" message_type = hl7.Field( COMPONENT_SEPARATOR, [ "ORU", # message type ID = Observ result/unsolicited "R01" # trigger event ID = ORU/ACK - Unsolicited transmission # of an observation message ], ) processing_id = "P" # production (processing mode: current) version_id = "2.3" # HL7 version sequence_number = "" continuation_pointer = "" accept_acknowledgement_type = "" application_acknowledgement_type = "AL" # always country_code = "" character_set = "UNICODE UTF-8" # http://wiki.hl7.org/index.php?title=Character_Set_used_in_v2_messages principal_language_of_message = "" fields = [ segment_id, # field separator inserted automatically; HL7 standard considers it a # field but the python-hl7 processor doesn't when it parses encoding_characters, sending_application, sending_facility, receiving_application, receiving_facility, date_time_of_message, security, message_type, message_control_id, processing_id, version_id, sequence_number, continuation_pointer, accept_acknowledgement_type, application_acknowledgement_type, country_code, character_set, principal_language_of_message, ] segment = hl7.Segment(FIELD_SEPARATOR, fields) return segment
[docs]def make_pid_segment( forename: str, surname: str, dob: Date, sex: str, address: str, patient_id_list: List[HL7PatientIdentifier] = None, ) -> hl7.Segment: """ Creates an HL7 patient identification (PID) segment. - https://www.corepointhealth.com/resource-center/hl7-resources/hl7-pid-segment - https://www.hl7.org/documentcenter/public/wg/conf/Msgadt.pdf (s5.4.8) - ID numbers... https://www.cdc.gov/vaccines/programs/iis/technical-guidance/downloads/hl7guide-1-4-2012-08.pdf """ # noqa patient_id_list = patient_id_list or [] # type: List[HL7PatientIdentifier] segment_id = "PID" set_id = "" # External ID patient_external_id = "" # ... this one is deprecated # http://www.j4jayant.com/articles/hl7/16-patient-id # Internal ID internal_id_element_list = [] for i in range(len(patient_id_list)): if not patient_id_list[i].pid: continue ptidentifier = patient_id_list[i] pid = ptidentifier.pid check_digit = get_mod11_checkdigit(pid) check_digit_scheme = "M11" # Mod 11 algorithm type_id = patient_id_list[i].id_type assigning_authority = patient_id_list[i].assigning_authority # Now, as per Table 4.6 "Extended composite ID" of # hl7guide-1-4-2012-08.pdf: internal_id_element = hl7.Field( COMPONENT_SEPARATOR, [ pid, check_digit, check_digit_scheme, assigning_authority, type_id, # length "2..5" meaning 2-5 ], ) internal_id_element_list.append(internal_id_element) patient_internal_id = hl7.Field( REPETITION_SEPARATOR, internal_id_element_list ) # Alternate ID alternate_patient_id = "" # ... this one is deprecated # http://www.j4jayant.com/articles/hl7/16-patient-id patient_name = hl7.Field( COMPONENT_SEPARATOR, [ forename, # surname surname, # forename "", # middle initial/name "", # suffix (e.g. Jr, III) "", # prefix (e.g. Dr) "", # degree (e.g. MD) ], ) mothers_maiden_name = "" date_of_birth = format_datetime(dob, DateFormat.HL7_DATE) alias = "" race = "" country_code = "" home_phone_number = "" business_phone_number = "" language = "" marital_status = "" religion = "" account_number = "" social_security_number = "" drivers_license_number = "" mother_identifier = "" ethnic_group = "" birthplace = "" birth_order = "" citizenship = "" veterans_military_status = "" fields = [ segment_id, set_id, # PID.1 patient_external_id, # PID.2 patient_internal_id, # known as "PID-3" or "PID.3" alternate_patient_id, # PID.4 patient_name, mothers_maiden_name, date_of_birth, sex, alias, race, address, country_code, home_phone_number, business_phone_number, language, marital_status, religion, account_number, social_security_number, drivers_license_number, mother_identifier, ethnic_group, birthplace, birth_order, citizenship, veterans_military_status, ] segment = hl7.Segment(FIELD_SEPARATOR, fields) return segment
# noinspection PyUnusedLocal
[docs]def make_obr_segment(task: "Task") -> hl7.Segment: # noinspection HttpUrlsUsage """ Creates an HL7 observation request (OBR) segment. - http://hl7reference.com/HL7%20Specifications%20ORM-ORU.PDF - Required in ORU^R01 message: - https://www.corepointhealth.com/resource-center/hl7-resources/hl7-oru-message - https://www.corepointhealth.com/resource-center/hl7-resources/hl7-obr-segment """ # noqa segment_id = "OBR" set_id = "1" placer_order_number = "CamCOPS" filler_order_number = "CamCOPS" universal_service_id = hl7.Field( COMPONENT_SEPARATOR, ["CamCOPS", "CamCOPS psychiatric/cognitive assessment"], ) # unused below here, apparently priority = "" requested_date_time = "" observation_date_time = "" observation_end_date_time = "" collection_volume = "" collector_identifier = "" specimen_action_code = "" danger_code = "" relevant_clinical_information = "" specimen_received_date_time = "" ordering_provider = "" order_callback_phone_number = "" placer_field_1 = "" placer_field_2 = "" filler_field_1 = "" filler_field_2 = "" results_report_status_change_date_time = "" charge_to_practice = "" diagnostic_service_section_id = "" result_status = "" parent_result = "" quantity_timing = "" result_copies_to = "" parent = "" transportation_mode = "" reason_for_study = "" principal_result_interpreter = "" assistant_result_interpreter = "" technician = "" transcriptionist = "" scheduled_date_time = "" number_of_sample_containers = "" transport_logistics_of_collected_samples = "" collectors_comment = "" transport_arrangement_responsibility = "" transport_arranged = "" escort_required = "" planned_patient_transport_comment = "" fields = [ segment_id, set_id, placer_order_number, filler_order_number, universal_service_id, priority, requested_date_time, observation_date_time, observation_end_date_time, collection_volume, collector_identifier, specimen_action_code, danger_code, relevant_clinical_information, specimen_received_date_time, ordering_provider, order_callback_phone_number, placer_field_1, placer_field_2, filler_field_1, filler_field_2, results_report_status_change_date_time, charge_to_practice, diagnostic_service_section_id, result_status, parent_result, quantity_timing, result_copies_to, parent, transportation_mode, reason_for_study, principal_result_interpreter, assistant_result_interpreter, technician, transcriptionist, scheduled_date_time, number_of_sample_containers, transport_logistics_of_collected_samples, collectors_comment, transport_arrangement_responsibility, transport_arranged, escort_required, planned_patient_transport_comment, ] segment = hl7.Segment(FIELD_SEPARATOR, fields) return segment
[docs]def make_obx_segment( req: "CamcopsRequest", task: "Task", task_format: str, observation_identifier: str, observation_datetime: Pendulum, responsible_observer: str, export_options: "TaskExportOptions", ) -> hl7.Segment: # noinspection HttpUrlsUsage """ Creates an HL7 observation result (OBX) segment. - http://www.hl7standards.com/blog/2006/10/18/how-do-i-send-a-binary-file-inside-of-an-hl7-message - http://www.hl7standards.com/blog/2007/11/27/pdf-attachment-in-hl7-message/ - http://www.hl7standards.com/blog/2006/12/01/sending-images-or-formatted-documents-via-hl7-messaging/ - https://www.hl7.org/documentcenter/public/wg/ca/HL7ClmAttIG.PDF - type of data: https://www.hl7.org/implement/standards/fhir/v2/0191/index.html - subtype of data: https://www.hl7.org/implement/standards/fhir/v2/0291/index.html """ # noqa segment_id = "OBX" set_id = str(1) source_application = "CamCOPS" if task_format == FileType.PDF: value_type = "ED" # Encapsulated data (ED) field observation_value = hl7.Field( COMPONENT_SEPARATOR, [ source_application, "Application", # type of data "PDF", # data subtype "Base64", # base 64 encoding base64.standard_b64encode(task.get_pdf(req)), # data ], ) elif task_format == FileType.HTML: value_type = "ED" # Encapsulated data (ED) field observation_value = hl7.Field( COMPONENT_SEPARATOR, [ source_application, "TEXT", # type of data "HTML", # data subtype "A", # no encoding (see table 0299), but need to escape escape_hl7_text(task.get_html(req)), # data ], ) elif task_format == FileType.XML: value_type = "ED" # Encapsulated data (ED) field observation_value = hl7.Field( COMPONENT_SEPARATOR, [ source_application, "TEXT", # type of data "XML", # data subtype "A", # no encoding (see table 0299), but need to escape escape_hl7_text( task.get_xml( req, indent_spaces=0, eol="", options=export_options ) ), # data ], ) else: raise AssertionError( f"make_obx_segment: invalid task_format: {task_format}" ) observation_sub_id = "" units = "" reference_range = "" abnormal_flags = "" probability = "" nature_of_abnormal_test = "" observation_result_status = "" date_of_last_observation_normal_values = "" user_defined_access_checks = "" date_and_time_of_observation = format_datetime( observation_datetime, DateFormat.HL7_DATETIME ) producer_id = "" observation_method = "" equipment_instance_identifier = "" date_time_of_analysis = "" fields = [ segment_id, set_id, value_type, observation_identifier, observation_sub_id, observation_value, units, reference_range, abnormal_flags, probability, nature_of_abnormal_test, observation_result_status, date_of_last_observation_normal_values, user_defined_access_checks, date_and_time_of_observation, producer_id, responsible_observer, observation_method, equipment_instance_identifier, date_time_of_analysis, ] segment = hl7.Segment(FIELD_SEPARATOR, fields) return segment
[docs]def make_dg1_segment( set_id: int, diagnosis_datetime: Pendulum, coding_system: str, diagnosis_identifier: str, diagnosis_text: str, alternate_coding_system: str = "", alternate_diagnosis_identifier: str = "", alternate_diagnosis_text: str = "", diagnosis_type: str = "F", diagnosis_classification: str = "D", confidential_indicator: str = "N", clinician_id_number: Union[str, int] = None, clinician_surname: str = "", clinician_forename: str = "", clinician_middle_name_or_initial: str = "", clinician_suffix: str = "", clinician_prefix: str = "", clinician_degree: str = "", clinician_source_table: str = "", clinician_assigning_authority: str = "", clinician_name_type_code: str = "", clinician_identifier_type_code: str = "", clinician_assigning_facility: str = "", attestation_datetime: Pendulum = None, ) -> hl7.Segment: # noinspection HttpUrlsUsage """ Creates an HL7 diagnosis (DG1) segment. Args: .. code-block:: none set_id: Diagnosis sequence number, starting with 1 (use higher numbers for >1 diagnosis). diagnosis_datetime: Date/time diagnosis was made. coding_system: E.g. "I9C" for ICD9-CM; "I10" for ICD10. diagnosis_identifier: Code. diagnosis_text: Text. alternate_coding_system: Optional alternate coding system. alternate_diagnosis_identifier: Optional alternate code. alternate_diagnosis_text: Optional alternate text. diagnosis_type: A admitting, W working, F final. diagnosis_classification: C consultation, D diagnosis, M medication, O other, R radiological scheduling, S sign and symptom, T tissue diagnosis, I invasive procedure not classified elsewhere. confidential_indicator: Y yes, N no clinician_id_number: } Diagnosing clinician. clinician_surname: } clinician_forename: } clinician_middle_name_or_initial: } clinician_suffix: } clinician_prefix: } clinician_degree: } clinician_source_table: } clinician_assigning_authority: } clinician_name_type_code: } clinician_identifier_type_code: } clinician_assigning_facility: } attestation_datetime: Date/time the diagnosis was attested. - http://www.mexi.be/documents/hl7/ch600012.htm - https://www.hl7.org/special/committees/vocab/V26_Appendix_A.pdf """ segment_id = "DG1" try: int(set_id) set_id = str(set_id) except Exception: raise AssertionError("make_dg1_segment: set_id invalid") diagnosis_coding_method = "" diagnosis_code = hl7.Field( COMPONENT_SEPARATOR, [ diagnosis_identifier, diagnosis_text, coding_system, alternate_diagnosis_identifier, alternate_diagnosis_text, alternate_coding_system, ], ) diagnosis_description = "" diagnosis_datetime = format_datetime( diagnosis_datetime, DateFormat.HL7_DATETIME ) if diagnosis_type not in ("A", "W", "F"): raise AssertionError("make_dg1_segment: diagnosis_type invalid") major_diagnostic_category = "" diagnostic_related_group = "" drg_approval_indicator = "" drg_grouper_review_code = "" outlier_type = "" outlier_days = "" outlier_cost = "" grouper_version_and_type = "" diagnosis_priority = "" try: clinician_id_number = ( str(int(clinician_id_number)) if clinician_id_number is not None else "" ) except Exception: raise AssertionError( "make_dg1_segment: diagnosing_clinician_id_number" " invalid" ) if clinician_id_number: clinician_id_check_digit = get_mod11_checkdigit(clinician_id_number) clinician_checkdigit_scheme = "M11" # Mod 11 algorithm else: clinician_id_check_digit = "" clinician_checkdigit_scheme = "" diagnosing_clinician = hl7.Field( COMPONENT_SEPARATOR, [ clinician_id_number, clinician_surname or "", clinician_forename or "", clinician_middle_name_or_initial or "", clinician_suffix or "", clinician_prefix or "", clinician_degree or "", clinician_source_table or "", clinician_assigning_authority or "", clinician_name_type_code or "", clinician_id_check_digit or "", clinician_checkdigit_scheme or "", clinician_identifier_type_code or "", clinician_assigning_facility or "", ], ) if diagnosis_classification not in ( "C", "D", "M", "O", "R", "S", "T", "I", ): raise AssertionError( "make_dg1_segment: diagnosis_classification invalid" ) if confidential_indicator not in ("Y", "N"): raise AssertionError( "make_dg1_segment: confidential_indicator invalid" ) attestation_datetime = ( format_datetime(attestation_datetime, DateFormat.HL7_DATETIME) if attestation_datetime else "" ) fields = [ segment_id, set_id, diagnosis_coding_method, diagnosis_code, diagnosis_description, diagnosis_datetime, diagnosis_type, major_diagnostic_category, diagnostic_related_group, drg_approval_indicator, drg_grouper_review_code, outlier_type, outlier_days, outlier_cost, grouper_version_and_type, diagnosis_priority, diagnosing_clinician, diagnosis_classification, confidential_indicator, attestation_datetime, ] segment = hl7.Segment(FIELD_SEPARATOR, fields) return segment
[docs]def escape_hl7_text(s: str) -> str: # noinspection HttpUrlsUsage """ Escapes HL7 special characters. - http://www.mexi.be/documents/hl7/ch200034.htm - http://www.mexi.be/documents/hl7/ch200071.htm """ esc_escape = ESCAPE_CHARACTER + ESCAPE_CHARACTER + ESCAPE_CHARACTER esc_fieldsep = ESCAPE_CHARACTER + "F" + ESCAPE_CHARACTER esc_componentsep = ESCAPE_CHARACTER + "S" + ESCAPE_CHARACTER esc_subcomponentsep = ESCAPE_CHARACTER + "T" + ESCAPE_CHARACTER esc_repetitionsep = ESCAPE_CHARACTER + "R" + ESCAPE_CHARACTER # Linebreaks: # http://www.healthintersections.com.au/?p=344 # https://groups.google.com/forum/#!topic/ensemble-in-healthcare/wP2DWMeFrPA # noqa # http://www.hermetechnz.com/documentation/sqlschema/index.html?hl7_escape_rules.htm # noqa esc_linebreak = ESCAPE_CHARACTER + ".br" + ESCAPE_CHARACTER s = s.replace(ESCAPE_CHARACTER, esc_escape) # this one first! s = s.replace(FIELD_SEPARATOR, esc_fieldsep) s = s.replace(COMPONENT_SEPARATOR, esc_componentsep) s = s.replace(SUBCOMPONENT_SEPARATOR, esc_subcomponentsep) s = s.replace(REPETITION_SEPARATOR, esc_repetitionsep) s = s.replace("\n", esc_linebreak) return s
[docs]def msg_is_successful_ack(msg: hl7.Message) -> Tuple[bool, Optional[str]]: # noinspection HttpUrlsUsage """ Checks whether msg represents a successful acknowledgement message. - http://hl7reference.com/HL7%20Specifications%20ORM-ORU.PDF """ if msg is None: return False, "Reply is None" # Get segments (MSH, MSA) if len(msg) != 2: return False, f"Reply doesn't have 2 segments (has {len(msg)})" msh_segment = msg[0] msa_segment = msg[1] # Check MSH segment if len(msh_segment) < 9: return ( False, f"First (MSH) segment has <9 fields (has {len(msh_segment)})", ) msh_segment_id = msh_segment[0] msh_message_type = msh_segment[8] if msh_segment_id != ["MSH"]: return ( False, f"First (MSH) segment ID is not 'MSH' (is {msh_segment_id})", ) if msh_message_type != ["ACK"]: return ( False, f"MSH message type is not 'ACK' (is {msh_message_type})", ) # Check MSA segment if len(msa_segment) < 2: return ( False, f"Second (MSA) segment has <2 fields (has {len(msa_segment)})", ) msa_segment_id = msa_segment[0] msa_acknowledgment_code = msa_segment[1] if msa_segment_id != ["MSA"]: return ( False, f"Second (MSA) segment ID is not 'MSA' (is {msa_segment_id})", ) if msa_acknowledgment_code != ["AA"]: # AA for success, AE for error return ( False, ( f"MSA acknowledgement code is not 'AA' " f"(is {msa_acknowledgment_code})" ), ) return True, None
# ============================================================================= # MLLPTimeoutClient # ============================================================================= # Modification of MLLPClient from python-hl7, to allow timeouts and failure. SB = "\x0b" # <SB>, vertical tab EB = "\x1c" # <EB>, file separator CR = "\x0d" # <CR>, \r FF = "\x0c" # <FF>, new page form feed RECV_BUFFER = 4096
[docs]class MLLPTimeoutClient(object): """ Class for MLLP TCP/IP transmission that implements timeouts. """
[docs] def __init__(self, host: str, port: int, timeout_ms: int = None) -> None: """Creates MLLP client and opens socket.""" self.socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM) timeout_s = ( float(timeout_ms) / float(1000) if timeout_ms is not None else None ) self.socket.settimeout(timeout_s) self.socket.connect((host, port)) self.encoding = "utf-8"
def __enter__(self): """ For use with "with" statement. """ return self # noinspection PyUnusedLocal def __exit__(self, exc_type, exc_val, traceback): """ For use with "with" statement. """ self.close()
[docs] def close(self): """ Release the socket connection. """ self.socket.close()
[docs] def send_message( self, message: Union[str, hl7.Message] ) -> Tuple[bool, Optional[str]]: """ Wraps a string or :class:`hl7.Message` in a MLLP container and sends the message to the server. Returns ``success, ack_msg``. """ if isinstance(message, hl7.Message): message = str(message) # wrap in MLLP message container data = SB + message + CR + EB + CR # ... the CR immediately after the message is my addition, because # HL7 Inspector otherwise says: "Warning: last segment have no segment # termination char 0x0d !" (sic). return self.send(data.encode(self.encoding))
[docs] def send(self, data: bytes) -> Tuple[bool, Optional[str]]: """ Low-level, direct access to the ``socket.send`` function (data must be already wrapped in an MLLP container). Blocks until the server returns. Returns ``success, ack_msg``. """ # upload the data self.socket.send(data) # wait for the ACK/NACK try: ack_msg = self.socket.recv(RECV_BUFFER).decode(self.encoding) return True, ack_msg except socket.timeout: return False, None