Refactored Entiti constructor with multipledispatch

Author: fbattello

poetry.lock

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "ngsildclient"
-version = "0.5.0"
+version = "0.5.1"
 description = "A Python library that helps building NGSI-LD entities and interacting with a NGSI-LD Context Broker"
 license = "Apache-2.0"
 readme="README.md"
@@ -22,6 +22,7 @@ isodate = "^0.6.1"
 networkx = "^2.8.7"
 scalpl = "^0.4.2"
 python-dateutil = "^2.8.2"
+multipledispatch = "^0.6.0"
 
 [tool.poetry.dev-dependencies]
 pytest = "^7.1.3"

pyproject.toml

@@ -13,7 +13,7 @@
 import logging
 import sys
 
-__version__ = "0.5.0"
+__version__ = "0.5.1"
 
 from ngsildclient.settings import globalsettings as settings
 from .utils import iso8601, is_interactive

src/ngsildclient/__init__.py

@@ -45,6 +45,8 @@
         Sequence[entity.Entity],
     ]
 
+LD_PREFIX = "urn:ngsi-ld"
+
 NgsiLocation = Union[tuple[int, int], Point]
 """A user type : either a tuple of two ints (lat, lon) or a GeoJson Point.
 """

src/ngsildclient/model/constants.py

@@ -19,7 +19,6 @@
 
 from copy import deepcopy
 from functools import partialmethod
-
 from datetime import datetime
 from typing import (
     Sequence,
@@ -31,13 +30,13 @@
     Mapping,
     Callable,
 )
-
+from multipledispatch import dispatch
 
 from ngsildclient.model.ngsidict import NgsiDict
 from ngsildclient.utils import iso8601, url
 from ngsildclient.utils.urn import Urn
 from ngsildclient.model.exceptions import NgsiMissingIdError, NgsiMissingTypeError, NgsiMissingContextError
-from ngsildclient.model.constants import CORE_CONTEXT, Rel, NgsiDate, NgsiGeometry
+from ngsildclient.model.constants import CORE_CONTEXT, LD_PREFIX, Rel, NgsiDate, NgsiGeometry
 from ngsildclient.settings import globalsettings
 
 logger = logging.getLogger(__name__)
@@ -185,96 +184,38 @@ class Entity:
     >>> e.rm("NO2.accuracy")
     """
 
-    def __init__(
-        self,
-        *args: str,
-        ctx: List = None,
-        payload: dict = None,
-        autoprefix: Optional[bool] = None,
-    ):
-        """Create a NGSI-LD compliant entity
-
-        Expected args are : the Entity's type and identifier.
-        Example : Entity("AirQualityObserved", "RZ:Obsv4567")
-        The fully qualified identifier is built following the naming convention : "urn:ngsi-ld:{type}:{id}'.
-        "urn:ngsi-ld:" is added if not specified.
-
-        Alernatively a single arg is allowed : the fully qualified Entity's identifier.
-        Example : Entity("urn:ngsi-ld:AirQualityObserved:RZ:Obsv4567")
-        Type is inferred from the fully qualified identifier.
-
-        The default behaviour can be disabled : Entity.globalsettings.autoprefix = False.
-
-
-        Parameters
-        ----------
-        type : str
-            entity type
-        id : str
-            entity identifier
-        ctx : list, optional
-            the NGSI-LD context, by default the NGSI-LD Core Context
-
-        Example
-        -------
-        >>> from ngsildclient.model.entity import Entity
-        >>> e1 = Entity("AirQualityObserved", "urn:ngsi-ld:AirQualityObserved:RZ:Obsv4567") # long form
-        >>> e2 = Entity("AirQualityObserved", "AirQualityObserved:RZ:Obsv4567") # omit scheme + nss
-        >>> e3 = Entity("AirQualityObserved", "RZ:Obsv4567") # omit scheme + nss + type
-        >>> print(e1 == e2 == e3)
-        True
-        >>> e1.pprint()
-        {
-            "@context": [
-                "https://uri.etsi.org/ngsi-ld/v1/ngsi-ld-core-context.jsonld"
-            ],
-            "id": "urn:ngsi-ld:AirQualityObserved:RZ:Obsv4567",
-            "type": "AirQualityObserved"
-        }
-        """
-        self.root: NgsiDict = None
-        self._lastprop: NgsiDict = None
+    @staticmethod
+    def _build_fully_qualified_id(type: str, id: str) -> Urn:
+        if globalsettings.autoprefix:
+            bare_id = Urn.unprefix(id)
+            if not bare_id.startswith(f"{type}:"):
+                id = f"{type}:{bare_id}"
+        return Urn.prefix(id)
+
+    @dispatch(dict)
+    def __init__(self, payload: dict):
+        if not payload.get("id", None):
+            raise NgsiMissingIdError()
+        if not payload.get("type", None):
+            raise NgsiMissingTypeError()
+        if not payload.get("@context"):
+            payload["@context"] = [CORE_CONTEXT]
+        self._lastprop = self.root = NgsiDict(payload)
         self._anchored: bool = False
         self._lastwasmulti: bool = False
 
-        if len(args) == 2:
-            type, id = args
-        elif len(args) == 1:
-            id, type = args[0], None
-        elif len(args) == 0 and payload is not None:  # create Entity from a dictionary
-            if not payload.get("id", None):
-                raise NgsiMissingIdError()
-            if not payload.get("type", None):
-                raise NgsiMissingTypeError()
-            if not payload.get("@context", None):
-                raise NgsiMissingContextError()
-            self._lastprop = self.root = NgsiDict(payload)
-            return
-        else:
-            raise ValueError("Expecteds args : type, id (alt. fully qualified id)")
-
-        if autoprefix is None:
-            autoprefix = globalsettings.autoprefix
-        if not ctx:
-            ctx = [CORE_CONTEXT]
-
-        # create a new Entity using its id and type
-        if type is None:  # try to infer type from the fully qualified identifier
-            id = Urn.prefix(id)
-            urn = Urn(id)
-            if (type := urn.infertype()) is None:
-                raise NgsiMissingTypeError(f"{urn.fqn=}")
-        else:  # type is not None
-            autoprefix &= not Urn.is_prefixed(id)
-            if autoprefix:
-                bareid = Urn.shorten(id)
-                prefix = f"{type}:"
-                if not bareid.startswith(prefix):
-                    id = prefix + bareid
-            id = Urn.prefix(id)  # set the prefix "urn:ngsi-ld:" if not already done
-            urn = Urn(id)
-
-        self._lastprop = self.root = NgsiDict({"@context": ctx, "id": urn.fqn, "type": type})
+    @dispatch(str, str)
+    def __init__(self, type: str, id: str, *, ctx: List[str] = None):  # noqa F811
+        id = Entity._build_fully_qualified_id(type, id)
+        self.__init__({"id": id, "type": type, "@context": ctx or [CORE_CONTEXT]})
+
+    @dispatch(str)
+    def __init__(self, id: str, *, ctx: List[str] = None):  # noqa F811
+        id = Urn.prefix(id)
+        urn = Urn(id)
+        if (type := urn.infertype()) is None:
+            raise NgsiMissingTypeError(f"{urn.fqn=}")
+        self.__init__({"id": id, "type": type, "@context": ctx or [CORE_CONTEXT]})
 
     @classmethod
     def from_dict(cls, payload: dict):
@@ -293,7 +234,7 @@ def from_dict(cls, payload: dict):
         Entity
             The result Entity instance
         """
-        return cls(payload=payload)
+        return cls(payload)
 
     @classmethod
     def from_json(cls, content: str):
@@ -313,7 +254,7 @@ def from_json(cls, content: str):
             The result Entity instance
         """
         payload: dict = json.loads(content)
-        return cls(payload=payload)
+        return cls(payload)
 
     @classmethod
     def duplicate(cls, entity: Entity) -> Entity:

src/ngsildclient/model/entity.py

@@ -22,7 +22,6 @@
 import logging
 
 from typing import overload, Optional, Tuple
-from ngsildclient.api.constants import ENDPOINT_ENTITIES
 
 NID_PATTERN = re.compile(r"^[0-9a-zA-Z\-]+$")
 """Regex pattern that matches a valid namespace identifier (`regex.Pattern`).
@@ -49,8 +48,6 @@ class Urn:
     """Helper class to handle NGSI-LD urn/uri and allow to work with unprefixed strings."""
 
     DEFAULT_NID = "ngsi-ld"
-    # """Default NGSI-LD namespace value
-    # """
 
     @overload
     def __init__(self, fqn: str) -> None:
@@ -202,7 +199,7 @@ def prefix(value: str) -> str:
         return value if Urn.is_prefixed(value) else f"urn:ngsi-ld:{value}"
 
     @staticmethod
-    def shorten(value: str) -> str:
+    def unprefix(value: str) -> str:
         """Remove the prefix (URN scheme+NID)
 
         Parameters

src/ngsildclient/utils/urn.py

@@ -66,14 +66,14 @@ def test_constructor_type_and_id_without_scheme():
     assert e.id == "urn:ngsi-ld:AirQualityObserved:RZ:Obsv4567"
 
 
-def test_constructor_autoprefix_type_and_id_without_type_included():
-    e = Entity("AirQualityObserved", "RZ:Obsv4567", autoprefix=True)
+def test_constructor_type_and_id_without_type_included():
+    e = Entity("AirQualityObserved", "RZ:Obsv4567")
     assert e.type == "AirQualityObserved"
     assert e.id == "urn:ngsi-ld:AirQualityObserved:RZ:Obsv4567"
 
 
-def test_constructor_autoprefix_type_and_id_with_type_included():
-    e = Entity("AirQualityObserved", "AirQualityObserved:RZ:Obsv4567", autoprefix=True)
+def test_constructor_type_and_id_with_type_included():
+    e = Entity("AirQualityObserved", "AirQualityObserved:RZ:Obsv4567")
     assert e.type == "AirQualityObserved"
     assert e.id == "urn:ngsi-ld:AirQualityObserved:RZ:Obsv4567"
 
@@ -140,7 +140,7 @@ def test_air_quality_from_dict(expected_air_quality):
             "object": "urn:ngsi-ld:PointOfInterest:RZ:MainSquare",
         },
     }
-    e = Entity.from_dict(payload=payload)
+    e = Entity.from_dict(payload)
     assert e.to_dict() == expected_air_quality
 
 
@@ -207,7 +207,7 @@ def test_store():
     """
     e = Entity(
         "Store",
-        "Store:001",
+        "001",
         ctx=[
             {
                 "Store": "https://uri.etsi.org/ngsi-ld/primer/Store",

tests/test_entity.py

@@ -26,7 +26,7 @@ def test_type():
         "type": "Barn",
         "fillingLevel": {"type": "Property", "value": 0.6},
     }
-    e = Entity(payload=d)
+    e = Entity(d)
     prop = e["fillingLevel"]
     assert prop.type == "Property"
 

tests/test_ngsidict.py

@@ -13,4 +13,4 @@
 
 
 def test_version():
-    assert __version__ == "0.5.0"
+    assert __version__ == "0.5.1"

tests/test_ngsildclient.py

@@ -45,12 +45,12 @@ def test_valid_urn():
 
 def test_invalid_urn_bad_nid():
     with pytest.raises(UrnError):
-        urn = Urn("urn:ngsi*ld:test")
+        _ = Urn("urn:ngsi*ld:test")
 
 
 def test_invalid_urn_missing_nss():
     with pytest.raises(UrnError):
-        urn = Urn("urn:ngsi-ld:")
+        _ = Urn("urn:ngsi-ld:")
 
 
 def test_guess_from_string():