refactor(db)!: reference is now instance of a Database reference (#78)

Author: Salakar

samples/basic_db/functions/main.py

@@ -12,18 +12,22 @@
 @db_fn.on_value_written(reference="hello/world")
 def onwriteexample(event: db_fn.Event[db_fn.Change]) -> None:
     print("Hello from db write event:", event)
+    print("Reference path:", event.reference.path)
 
 
 @db_fn.on_value_created(reference="hello/world")
 def oncreatedexample(event: db_fn.Event) -> None:
     print("Hello from db create event:", event)
+    print("Reference path:", event.reference.path)
 
 
 @db_fn.on_value_deleted(reference="hello/world")
 def ondeletedexample(event: db_fn.Event) -> None:
     print("Hello from db delete event:", event)
+    print("Reference path:", event.reference.path)
 
 
 @db_fn.on_value_updated(reference="hello/world")
 def onupdatedexample(event: db_fn.Event[db_fn.Change]) -> None:
     print("Hello from db updated event:", event)
+    print("Reference path:", event.reference.path)

src/firebase_functions/db_fn.py

@@ -23,7 +23,10 @@
 import firebase_functions.private.path_pattern as _path_pattern
 import firebase_functions.core as _core
 import cloudevents.http as _ce
+import firebase_admin as _fa
+import firebase_admin.db as _db
 
+from firebase_admin.db import Reference
 from firebase_functions.options import DatabaseOptions
 from firebase_functions.core import Change, T
 
@@ -49,9 +52,9 @@ class Event(_core.CloudEvent[T]):
     The instance ID portion of the fully qualified resource name.
     """
 
-    reference: str
+    reference: Reference
     """
-    The database reference path.
+    The database reference.
     """
 
     location: str
@@ -96,16 +99,24 @@ def _db_endpoint_handler(
             before=before,
             after=after,
         )
+    if _fa._DEFAULT_APP_NAME not in _fa._apps:
+        _fa.initialize_app()
+    app = _fa.get_app()
     event_instance = event_attributes["instance"]
-    event_ref = event_attributes["ref"]
+    event_database_host = event_attributes["firebasedatabasehost"]
+    database_reference = _db.reference(
+        path=event_attributes["ref"],
+        app=app,
+        url=f"https://{event_instance}.{event_database_host}",
+    )
     params: dict[str, str] = {
-        **ref_pattern.extract_matches(event_ref),
+        **ref_pattern.extract_matches(event_attributes["ref"]),
         **instance_pattern.extract_matches(event_instance),
     }
     database_event = Event(
-        firebase_database_host=event_attributes["firebasedatabasehost"],
+        firebase_database_host=event_database_host,
         instance=event_instance,
-        reference=event_ref,
+        reference=database_reference,
         location=event_attributes["location"],
         specversion=event_attributes["specversion"],
         id=event_attributes["id"],