experimenting with version detection

dsmr_parser/objects.py

@@ -1,4 +1,7 @@
 class DSMRObject(object):
+    """
+    Represents all data from a single telegram line.
+    """
 
     def __init__(self, values):
         self.values = values

dsmr_parser/parsers.py

@@ -27,7 +27,7 @@ class TelegramParser(object):
 
         The telegram str type makes python 2.x integration easier.
 
-        :param str telegram: full telegram from start ('/') to checksum
+        :param str telegram_data: full telegram from start ('/') to checksum
             ('!ABCD') including line endings in between the telegram's lines
         :rtype: dict
         :returns: Shortened example:
@@ -51,7 +51,11 @@ class TelegramParser(object):
         for signature, parser in self.telegram_specification['objects'].items():
             match = re.search(signature, telegram_data, re.DOTALL)
 
-            if match:
+            # All telegram specification lines/signatures are expected to be
+            # present.
+            if not match:
+                raise ParseError('Telegram specification does not match '
+                                 'telegram data')
             telegram[signature] = parser.parse(match.group(0))
 
         return telegram
@@ -90,6 +94,31 @@ class TelegramParser(object):
             )
 
 
+def match_telegram_specification(telegram_data):
+    """
+    Find telegram specification that matches the telegram data by trying all
+    specifications.
+
+    Could be further optimized to check the actual 0.2.8 OBIS reference which
+    is available for DSMR version 4 and up.
+
+    :param str telegram_data: full telegram from start ('/') to checksum
+            ('!ABCD') including line endings in between the telegram's lines
+    :return: telegram specification
+    :rtype: dict
+    """
+    # Prevent circular import
+    from dsmr_parser import telegram_specifications
+
+    for specification in telegram_specifications.ALL:
+        try:
+            TelegramParser(specification).parse(telegram_data)
+        except ParseError:
+            pass
+        else:
+            return specification
+
+
 class DSMRObjectParser(object):
     """
     Parses an object (can also be see as a 'line') from a telegram.

dsmr_parser/telegram_specifications.py

@@ -42,34 +42,7 @@ V2_2 = {
     }
 }
 
-V3 = {
-    'checksum_support': False,
-    'objects': {
-        obis.EQUIPMENT_IDENTIFIER: CosemParser(ValueParser(str)),
-        obis.ELECTRICITY_USED_TARIFF_1: CosemParser(ValueParser(Decimal)),
-        obis.ELECTRICITY_USED_TARIFF_2: CosemParser(ValueParser(Decimal)),
-        obis.ELECTRICITY_DELIVERED_TARIFF_1: CosemParser(ValueParser(Decimal)),
-        obis.ELECTRICITY_DELIVERED_TARIFF_2: CosemParser(ValueParser(Decimal)),
-        obis.ELECTRICITY_ACTIVE_TARIFF: CosemParser(ValueParser(str)),
-        obis.CURRENT_ELECTRICITY_USAGE: CosemParser(ValueParser(Decimal)),
-        obis.CURRENT_ELECTRICITY_DELIVERY: CosemParser(ValueParser(Decimal)),
-        obis.ACTUAL_TRESHOLD_ELECTRICITY: CosemParser(ValueParser(Decimal)),
-        obis.ACTUAL_SWITCH_POSITION: CosemParser(ValueParser(str)),
-        obis.TEXT_MESSAGE_CODE: CosemParser(ValueParser(int)),
-        obis.TEXT_MESSAGE: CosemParser(ValueParser(str)),
-        obis.EQUIPMENT_IDENTIFIER_GAS: CosemParser(ValueParser(str)),
-        obis.DEVICE_TYPE: CosemParser(ValueParser(str)),
-        obis.VALVE_POSITION_GAS: CosemParser(ValueParser(str)),
-        obis.GAS_METER_READING: MBusParser(
-            ValueParser(timestamp),
-            ValueParser(int),
-            ValueParser(int),
-            ValueParser(int),
-            ValueParser(str),
-            ValueParser(Decimal),
-        ),
-    }
-}
+V3 = V2_2
 
 V4 = {
     'checksum_support': True,
@@ -145,3 +118,5 @@ V5 = {
         )
     }
 }
+
+ALL = (V2_2, V3, V4, V5)

test/test_match_telegram_specification.py

@@ -0,0 +1,25 @@
+import unittest
+
+from dsmr_parser.parsers import match_telegram_specification
+from dsmr_parser import telegram_specifications
+from test import example_telegrams
+
+
+class MatchTelegramSpecificationTest(unittest.TestCase):
+
+
+    def test_v2_2(self):
+        assert match_telegram_specification(example_telegrams.TELEGRAM_V2_2) \
+           == telegram_specifications.V2_2
+
+    def test_v3(self):
+        assert match_telegram_specification(example_telegrams.TELEGRAM_V3) \
+           == telegram_specifications.V3
+
+    def test_v4_2(self):
+        assert match_telegram_specification(example_telegrams.TELEGRAM_V4_2) \
+           == telegram_specifications.V4
+
+    def test_v5(self):
+        assert match_telegram_specification(example_telegrams.TELEGRAM_V5) \
+           == telegram_specifications.V5