Development

CHANGELOG.rst

@@ -1,6 +1,10 @@
 Change Log
 ----------
 
+**0.9** (2017-03-02)
+
+- allow the telegram specification to optionally be autodetected
+
 **0.8** (2017-01-26)
 
 - added support for DSMR v3

dsmr_parser/exceptions.py

@@ -4,3 +4,7 @@ class ParseError(Exception):
 
 class InvalidChecksumError(ParseError):
     pass
+
+
+class TelegramSpecificationMatchError(ParseError):
+    pass

dsmr_parser/parsers.py

@@ -4,16 +4,18 @@
 from PyCRC.CRC16 import CRC16
 
 from dsmr_parser.objects import MBusObject, CosemObject
-from dsmr_parser.exceptions import ParseError, InvalidChecksumError
+from dsmr_parser.exceptions import ParseError, InvalidChecksumError, \
+    TelegramSpecificationMatchError
 
 logger = logging.getLogger(__name__)
 
 
 class TelegramParser(object):
 
-    def __init__(self, telegram_specification, apply_checksum_validation=True):
+    def __init__(self, telegram_specification=None, apply_checksum_validation=True):
         """
-        :param telegram_specification: determines how the telegram is parsed
+        :param telegram_specification: determines how the telegram is parsed.
+            Will attempt to autodetect if omitted.
         :param apply_checksum_validation: validate checksum if applicable for
             telegram DSMR version (v4 and up).
         :type telegram_specification: dict
@@ -39,8 +41,10 @@ def parse(self, telegram_data):
                 ..
             }
         :raises ParseError:
-        :raises InvalidChecksumError:
         """
+        if not self.telegram_specification:
+            self.telegram_specification = \
+                match_telegram_specification(telegram_data)
 
         if self.apply_checksum_validation \
                 and self.telegram_specification['checksum_support']:
@@ -118,6 +122,11 @@ def match_telegram_specification(telegram_data):
         else:
             return specification
 
+    raise TelegramSpecificationMatchError(
+        'Could automatically match telegram specification. Make sure the data'
+        'is not corrupt. Alternatively manually specify one.'
+    )
+
 
 class DSMRObjectParser(object):
     """

setup.py

@@ -6,7 +6,7 @@
     author='Nigel Dokter',
     author_email='[email protected]',
     url='https://github.com/ndokter/dsmr_parser',
-    version='0.8',
+    version='0.9',
     packages=find_packages(),
     install_requires=[
         'pyserial>=3,<4',

test/test_match_telegram_specification.py

@@ -1,5 +1,6 @@
 import unittest
 
+from dsmr_parser.exceptions import TelegramSpecificationMatchError
 from dsmr_parser.parsers import match_telegram_specification
 from dsmr_parser import telegram_specifications
 from test import example_telegrams
@@ -22,3 +23,7 @@ def test_v4_2(self):
     def test_v5(self):
         assert match_telegram_specification(example_telegrams.TELEGRAM_V5) \
            == telegram_specifications.V5
+
+    def test_malformed_telegram(self):
+        with self.assertRaises(TelegramSpecificationMatchError):
+            match_telegram_specification(example_telegrams.TELEGRAM_V5[:-4])

test/test_parse_v2_2.py

@@ -12,6 +12,15 @@
 class TelegramParserV2_2Test(unittest.TestCase):
     """ Test parsing of a DSMR v2.2 telegram. """
 
+    def test_telegram_specification_matching(self):
+        parser = TelegramParser()
+        parser.parse(TELEGRAM_V2_2)
+
+        self.assertEqual(
+            parser.telegram_specification,
+            telegram_specifications.V2_2
+        )
+
     def test_parse(self):
         parser = TelegramParser(telegram_specifications.V2_2)
         result = parser.parse(TELEGRAM_V2_2)

test/test_parse_v3.py

@@ -12,6 +12,15 @@
 class TelegramParserV3Test(unittest.TestCase):
     """ Test parsing of a DSMR v3 telegram. """
 
+    def test_telegram_specification_matching(self):
+        parser = TelegramParser()
+        parser.parse(TELEGRAM_V3)
+
+        self.assertEqual(
+            parser.telegram_specification,
+            telegram_specifications.V3
+        )
+
     def test_parse(self):
         parser = TelegramParser(telegram_specifications.V3)
         result = parser.parse(TELEGRAM_V3)

test/test_parse_v4_2.py

@@ -15,6 +15,15 @@
 class TelegramParserV4_2Test(unittest.TestCase):
     """ Test parsing of a DSMR v4.2 telegram. """
 
+    def test_telegram_specification_matching(self):
+        parser = TelegramParser()
+        parser.parse(TELEGRAM_V4_2)
+
+        self.assertEqual(
+            parser.telegram_specification,
+            telegram_specifications.V4
+        )
+
     def test_parse(self):
         parser = TelegramParser(telegram_specifications.V4)
         result = parser.parse(TELEGRAM_V4_2)

test/test_parse_v5.py

@@ -16,6 +16,15 @@
 class TelegramParserV5Test(unittest.TestCase):
     """ Test parsing of a DSMR v5.x telegram. """
 
+    def test_telegram_specification_matching(self):
+        parser = TelegramParser()
+        parser.parse(TELEGRAM_V5)
+
+        self.assertEqual(
+            parser.telegram_specification,
+            telegram_specifications.V5
+        )
+
     def test_parse(self):
         parser = TelegramParser(telegram_specifications.V5)
         result = parser.parse(TELEGRAM_V5)