preparing novel endpoints for getlatest. Initially tried with berths, which does not have PUT/POST/DEL endpoints.

src/server/BreCal/api/__init__.py

@@ -0,0 +1,34 @@
+import typing
+import datetime
+
+# global dictionary, which informs about the latest change of a given database (e.g., 'berths')
+latest_get_request_dict = {database:None for database in ["berths", "history", "notifications", "participant", "shipcalls", "ships", "times", "user"]}
+
+def update_latest_modification_time(key:str, modification_time:datetime.datetime)->None:
+    """
+    This function updates the {latest_get_request_dict} inplace at the specified {key} with the defined {modification_time},
+    *if* the time is more recent than the currently stored value
+    """
+    global latest_get_request_dict
+    print(f"(update_latest_modification_time INFO): before executing the funtion", latest_get_request_dict, key, modification_time)
+    value = latest_get_request_dict.get(key,None)
+    if value is None:
+        # when there is no value stored for the key, update the value
+        latest_get_request_dict[key] = modification_time
+    else:
+        # when the modification date is more recent than the stored value, update it
+        if modification_time > value:
+            latest_get_request_dict[key] = modification_time
+    print(f"(update_latest_modification_time INFO): after executing the funtion", latest_get_request_dict, key, modification_time)
+    return
+
+def get_latest_modification_time(key:str)->typing.Optional[str]:
+    """
+    This function returns the latest modification time in .isoformat, if a datetime is stored for the respective key in {latest_get_request_dict}.
+    When there has not yet been an update, this function returns None
+    """
+    value = latest_get_request_dict.get(key,None)
+    if isinstance(value,datetime.datetime):
+        return value.isoformat()
+    return value # None
+    

src/server/BreCal/api/berths.py

@@ -16,3 +16,13 @@ def GetBerths():
         return impl.berths.GetBerths(token)
     else:
         return json.dumps("not authenticated"), 403
+
+@bp.route('/getlatestberths', methods=['get'])
+@auth_guard() # no restriction by role
+def GetLatestBerths():
+
+    if 'Authorization' in request.headers:
+        token = request.headers.get('Authorization')        
+        return impl.berths.GetLatestBerths(token)
+    else:
+        return json.dumps("not authenticated"), 403

src/server/BreCal/impl/berths.py

@@ -1,9 +1,11 @@
 import json
 import logging
 import pydapper
+import datetime
 
 from ..schemas import model
 from .. import local_db
+from BreCal.api import latest_get_request_dict, update_latest_modification_time, get_latest_modification_time
 
 def GetBerths(token):
     """
@@ -14,6 +16,8 @@ def GetBerths(token):
         pooledConnection = local_db.getPoolConnection()
         commands = pydapper.using(pooledConnection)
         data = commands.query("SELECT id, name, `lock`, owner_id, authority_id, created, modified, deleted FROM berth WHERE deleted = 0 ORDER BY name", model=model.Berth)
+        # update_latest_modification_time(key="berths", modification_time=datetime.datetime.now())
+        
         return json.dumps(data, default=model.obj_dict), 200, {'Content-Type': 'application/json; charset=utf-8'}
 
     except Exception as ex:
@@ -28,5 +32,29 @@ def GetBerths(token):
             pooledConnection.close()
 
 
+def GetLatestBerths(token):
+    """
+    Returns a datetime of the latest modification within the berths database. When there has not yet been a modification, this method returns null.
+    
+    # #TODO: should this become a data model?
+    """
+
+    try:
+        modification_time = get_latest_modification_time(key="berths")
+        data = {"key":"berths", "value":modification_time}
+        
+        return json.dumps(data), 200, {'Content-Type': 'application/json; charset=utf-8'}
+
+    except Exception as ex:
+        logging.error(ex)
+        print(ex)
+        result = {}
+        result["message"] = "call failed"
+        return json.dumps(result), 500
+
+
+
+
+
 
 

src/server/BreCal/impl/history.py

@@ -7,6 +7,7 @@ from ..schemas import model
 from ..schemas.model import History
 
 from .. import local_db
+from BreCal.api import latest_get_request_dict, update_latest_modification_time
 
 def GetHistory(options):
 

src/server/BreCal/impl/login.py

@@ -6,6 +6,7 @@ import bcrypt
 from ..schemas import model
 from .. import local_db
 from ..services import jwt_handler
+from BreCal.api import latest_get_request_dict, update_latest_modification_time
 
 def GetUser(options):
 

src/server/BreCal/impl/notifications.py

@@ -4,6 +4,7 @@ import pydapper
 
 from ..schemas import model
 from .. import local_db
+from BreCal.api import latest_get_request_dict, update_latest_modification_time
 
 def GetNotifications(options):
     """

src/server/BreCal/impl/participant.py

@@ -4,6 +4,7 @@ import pydapper
 
 from ..schemas import model
 from .. import local_db
+from BreCal.api import latest_get_request_dict, update_latest_modification_time
 
 def GetParticipant(options):
     """

src/server/BreCal/impl/shipcalls.py

@@ -8,6 +8,7 @@ from .. import local_db
 from ..services.auth_guard import check_jwt
 
 from BreCal.database.update_database import evaluate_shipcall_state
+from BreCal.api import latest_get_request_dict, update_latest_modification_time
 
 def GetShipcalls(options):
     """

src/server/BreCal/impl/ships.py

@@ -1,9 +1,11 @@
 import json
 import logging
 import pydapper
+import datetime
 
 from ..schemas import model
 from .. import local_db
+from BreCal.api import latest_get_request_dict, update_latest_modification_time
 
 def GetShips(token):
     """
@@ -11,10 +13,10 @@ def GetShips(token):
     """
 
     try:
-
         pooledConnection = local_db.getPoolConnection()
         commands = pydapper.using(pooledConnection)
         data = commands.query("SELECT id, name, imo, callsign, participant_id, length, width, is_tug, bollard_pull, eni, created, modified, deleted FROM ship ORDER BY name", model=model.Ship)
+        update_latest_modification_time(key="ships", modification_time=datetime.datetime.now())
 
         return json.dumps(data, default=model.obj_dict), 200, {'Content-Type': 'application/json; charset=utf-8'}
 

src/server/BreCal/impl/times.py

@@ -6,6 +6,7 @@ import pydapper
 from ..schemas import model
 from .. import local_db
 from ..services.auth_guard import check_jwt
+from BreCal.api import latest_get_request_dict, update_latest_modification_time
 
 from BreCal.database.update_database import evaluate_shipcall_state
 

src/server/BreCal/impl/user.py

@@ -5,6 +5,7 @@ import bcrypt
 
 from ..schemas import model
 from .. import local_db
+from BreCal.api import latest_get_request_dict, update_latest_modification_time
 
 def PutUser(schemaModel):
     """