# External ID support for serializer

* adds support for sending "external_identifier" in POST and PUT requests
* if an external identifier already exists on the database, the client will be informed that the entry should not be POSTed again but rather an update via PUT should be performed

api/utils/serializer/v1/compensation.py

@@ -113,7 +113,9 @@ class CompensationAPISerializerV1(AbstractModelAPISerializerV1, AbstractCompensa
             obj = self._initialize_objects(json_model, user)
 
             # Fill in data to objects
-            properties = json_model["properties"]
+            properties = json_model.get("properties", None)
+            if not properties:
+                raise AssertionError("No 'properties' found in payload!")
             obj.identifier = obj.generate_new_identifier()
             obj.title = properties["title"]
             obj.is_cef = properties["is_cef"]
@@ -129,6 +131,7 @@ class CompensationAPISerializerV1(AbstractModelAPISerializerV1, AbstractCompensa
             obj = self._set_compensation_states(obj, properties["after_states"], obj.after_states)
             obj = self._set_deadlines(obj, properties["deadlines"])
 
+        self._set_external_identifier(obj, properties.get("external_identifier", None))
         obj.log.add(obj.created)
 
         celery_update_parcels.delay(obj.geometry.id)
@@ -153,6 +156,10 @@ class CompensationAPISerializerV1(AbstractModelAPISerializerV1, AbstractCompensa
 
             # Fill in data to objects
             properties = json_model["properties"]
+
+            external_identifier = properties.get("external_identifier", None)
+            self._check_external_identifier_on_entry_creation(external_identifier)
+
             obj.title = properties["title"]
             obj.is_cef = properties["is_cef"]
             obj.is_coherence_keeping = properties["is_coherence_keeping"]
@@ -170,6 +177,7 @@ class CompensationAPISerializerV1(AbstractModelAPISerializerV1, AbstractCompensa
             obj = self._set_compensation_states(obj, properties["after_states"], obj.after_states)
             obj = self._set_deadlines(obj, properties["deadlines"])
 
+        self._set_external_identifier(obj, properties.get("external_identifier", None))
         obj.log.add(update_action)
 
         celery_update_parcels.delay(obj.geometry.id)

api/utils/serializer/v1/ecoaccount.py

@@ -121,7 +121,9 @@ class EcoAccountAPISerializerV1(AbstractModelAPISerializerV1,
             obj = self._initialize_objects(json_model, user)
 
             # Fill in data to objects
-            properties = json_model["properties"]
+            properties = json_model.get("properties", None)
+            if not properties:
+                raise AssertionError("No 'properties' found in payload!")
             obj.identifier = obj.generate_new_identifier()
             obj.title = properties["title"]
             obj.is_pik = properties.get("is_pik", False)
@@ -147,6 +149,7 @@ class EcoAccountAPISerializerV1(AbstractModelAPISerializerV1,
             obj = self._set_compensation_states(obj, properties["after_states"], obj.after_states)
             obj = self._set_deadlines(obj, properties["deadlines"])
 
+        self._set_external_identifier(obj, properties.get("external_identifier", None))
         obj.log.add(obj.created)
         obj.users.add(user)
 
@@ -172,6 +175,10 @@ class EcoAccountAPISerializerV1(AbstractModelAPISerializerV1,
 
             # Fill in data to objects
             properties = json_model["properties"]
+
+            external_identifier = properties.get("external_identifier", None)
+            self._check_external_identifier_on_entry_creation(external_identifier)
+
             obj.title = properties["title"]
             obj.is_pik = properties.get("is_pik", False)
             obj.deductable_surface = float(properties["deductable_surface"])
@@ -192,6 +199,7 @@ class EcoAccountAPISerializerV1(AbstractModelAPISerializerV1,
             obj = self._set_compensation_states(obj, properties["after_states"], obj.after_states)
             obj = self._set_deadlines(obj, properties["deadlines"])
 
+        self._set_external_identifier(obj, external_identifier)
         obj.log.add(update_action)
 
         celery_update_parcels.delay(obj.geometry.id)

api/utils/serializer/v1/ema.py

@@ -104,6 +104,10 @@ class EmaAPISerializerV1(AbstractModelAPISerializerV1, AbstractCompensationAPISe
 
             # Fill in data to objects
             properties = json_model["properties"]
+
+            external_identifier = properties.get("external_identifier", None)
+            self._check_external_identifier_on_entry_creation(external_identifier)
+
             obj.identifier = obj.generate_new_identifier()
             obj.title = properties["title"]
             obj.is_pik = properties.get("is_pik", False)
@@ -119,6 +123,7 @@ class EmaAPISerializerV1(AbstractModelAPISerializerV1, AbstractCompensationAPISe
             obj = self._set_compensation_states(obj, properties["after_states"], obj.after_states)
             obj = self._set_deadlines(obj, properties["deadlines"])
 
+        self._set_external_identifier(obj, external_identifier)
         obj.log.add(obj.created)
         obj.users.add(user)
 
@@ -161,6 +166,7 @@ class EmaAPISerializerV1(AbstractModelAPISerializerV1, AbstractCompensationAPISe
             obj = self._set_compensation_states(obj, properties["after_states"], obj.after_states)
             obj = self._set_deadlines(obj, properties["deadlines"])
 
+        self._set_external_identifier(obj, properties.get("external_identifier", None))
         obj.log.add(update_action)
 
         celery_update_parcels.delay(obj.geometry.id)

api/utils/serializer/v1/intervention.py

@@ -150,10 +150,14 @@ class InterventionAPISerializerV1(AbstractModelAPISerializerV1,
 
             # Fill in data to objects
             properties = json_model["properties"]
+
+            external_identifier = properties.get("external_identifier", None)
+            self._check_external_identifier_on_entry_creation(external_identifier)
+
             obj.identifier = obj.generate_new_identifier()
-            obj.title = properties["title"]
+            obj.title = properties.get("title", None)
-            self._set_responsibility(obj, properties["responsible"])
+            self._set_responsibility(obj, properties.get("responsible", None))
-            self._set_legal(obj, properties["legal"])
+            self._set_legal(obj, properties.get("legal", None))
 
             obj.responsible.handler.save()
             obj.responsible.save()
@@ -161,6 +165,7 @@ class InterventionAPISerializerV1(AbstractModelAPISerializerV1,
             obj.legal.save()
             obj.save()
 
+        self._set_external_identifier(obj, external_identifier)
         obj.users.add(user)
         obj.log.add(obj.created)
 
@@ -186,7 +191,7 @@ class InterventionAPISerializerV1(AbstractModelAPISerializerV1,
 
             # Fill in data to objects
             properties = json_model["properties"]
-            obj.title = properties["title"]
+            obj.title = properties.get("title")
             self._set_responsibility(obj, properties.get("responsible", None))
             self._set_legal(obj, properties.get("legal", None))
             self._set_payments(obj, properties.get("payments", None))
@@ -199,6 +204,7 @@ class InterventionAPISerializerV1(AbstractModelAPISerializerV1,
             obj.legal.save()
             obj.save()
 
+        self._set_external_identifier(obj, properties.get("external_identifier", None))
         obj.mark_as_edited(user, edit_comment="API update")
         obj.send_data_to_egon()
 

api/utils/serializer/v1/serializer.py

@@ -12,6 +12,7 @@ from django.contrib.gis.geos import MultiPolygon
 from django.core.exceptions import ObjectDoesNotExist
 from django.db.models import QuerySet
 
+from api.models import ExternalIdentifier
 from api.utils.serializer.serializer import AbstractModelAPISerializer
 from codelist.models import KonovaCode
 from codelist.settings import CODELIST_COMPENSATION_ACTION_ID, CODELIST_BIOTOPES_ID, CODELIST_PROCESS_TYPE_ID, \
@@ -137,6 +138,63 @@ class AbstractModelAPISerializerV1(AbstractModelAPISerializer):
         success = entry.deleted is not None
         return success
 
+    def _set_external_identifier(self, obj, external_identifier):
+        """ If an external identifier was provided in the payload, we set it
+        in the database
+
+        Args:
+            obj (BaseObject): The already processed konova object (EIV, KOM, ...)
+            external_identifier (any): The external identifier taken from the payload
+
+        Returns:
+
+        """
+        if external_identifier is None:
+            return None
+
+        ext_id_obj = ExternalIdentifier.objects.get_or_create(
+            internal_id=obj.id,
+            external_id=external_identifier
+        )[0]
+        if not ext_id_obj.created:
+            ext_id_obj.created = obj.created
+            ext_id_obj.save()
+
+        return ext_id_obj
+
+    def _get_external_identifier(self, external_identifier):
+        """ Checks whether a linkage based on an external identifier already exists and returns it if so.
+
+        Args:
+            external_identifier (any): The external identifier according to payload
+
+        Returns:
+            ExternalIdentifier | None
+        """
+        if external_identifier:
+            try:
+                obj = ExternalIdentifier.objects.get(external_id=external_identifier)
+                return obj
+            except ObjectDoesNotExist:
+                pass
+        return None
+
+    def _check_external_identifier_on_entry_creation(self, external_identifier):
+        """ Special check for POST processing:
+        Checks whether an external identifier already exists on the database. This hints that
+        the entry already has been created in the past. Instead of POST, the PUT method shall be used
+        to avoid creating duplicates.
+
+        Args:
+            external_identifier (any): The external identifier according to payload
+
+        Returns:
+
+        """
+        persisted_external_identifier = self._get_external_identifier(external_identifier)
+        if persisted_external_identifier:
+            raise AssertionError(f"{external_identifier} has already been initially created! Use PUT for updates!")
+
 
 class DeductableAPISerializerV1Mixin:
     class Meta: