Merge pull request #3 from immmdreza/master-entity

Change how __aenter__ works on collections ( now saves on exit ).

Author: immmdreza

README.md

@@ -4,6 +4,17 @@ This is a simple json database.
 The package provides a simple ORM between python objects and
 json objects with a well type-hinted schema.
 
+```py
+engine = AppEngine()
+
+async with engine.students as students:
+    students.add_range(Student("John", "Doe"), Student("Jane", "Doe"))
+
+async for student in engine.students:
+    print(student.first_name, student.last_name)
+    # Can you guess ? )
+```
+
 This package maps your python objects to json and then you can save, get,
 modify or delete them using async methods.
 
@@ -64,7 +75,8 @@ the model will automatically collect properties form `__init__` method.
 
 ### Creating collection ?
 
-It's really not necessary to create a collection by your own! And maybe you better )
+It's really not necessary to create a collection by your own!
+And maybe you better )
 
 Let us do that for ya ( Of course you can create customized Collections ).
 
@@ -76,11 +88,8 @@ Now you need to setup database's engine and define your collections there.
 # ---- sniff ----
 
 class AppEngine(Engine):
-
+    __db_path__ = "my_database"
     persons = Engine.set(Person)
-
-    def __init__(self):
-        super().__init__("MoyDatabase")
 ```
 
 That's all you need to do for now.
@@ -112,13 +121,13 @@ async def main():
     engine = AppEngine()
     collection = engine.persons
 
-    collection.add_range(
-        Person("John", "Doe", 20),
-        Person("Jane", "Doe", 21),
-        Person("Jack", "jones", 22),
-        Person("Jill", "jones", 23),
-    )
-    await collection.save_changes_async()
+    async with collection:
+        collection.add_range(
+            Person("John", "Doe", 20),
+            Person("Jane", "Doe", 21),
+            Person("Jack", "jones", 22),
+            Person("Jill", "jones", 23),
+        )
 
 ```
 

setup.cfg

@@ -1,6 +1,6 @@
 [metadata]
 name = json-entity
-version = 0.1.2.5
+version = 0.1.3.1
 author = immmdreza
 author_email = ir310022@gmail.com
 description = A simple and async json database.

src/examples/shifting_syntax.py

@@ -19,26 +19,24 @@ async def main():
     engine = AppEngine()
     customers_collection = engine.customers
 
-    customers_collection <<= Customer("Arash"), Customer("Sara")
-    tracked = Customer("Kiarash") >> customers_collection
-    # Both of above ways will call add() method of customers_collection
-    # using second way, you can only add one! but you receive a free tracking instance
-    # which contains information about changes in entity, and entity id.
-    print("A new entity will be added with id:", tracked.key)
-
-    await customers_collection.save_changes_async()
-
-    async for customer in customers_collection:
-        customers_collection >>= customer
-        # Using above syntax is same as calling: customers_collection.delete(customer)
-        break
-
-    # Again, using below syntax, you can get tracking instance as well.
-    async for customer in customers_collection:
-        tracked = customer << customers_collection
-        print(f"An entity with id {tracked.key}, is going to be deleted!")
-
-    await customers_collection.save_changes_async()
+    async with customers_collection:  # <-- this will save changes automatically on exit
+        customers_collection <<= Customer("Arash"), Customer("Sara")
+        tracked = Customer("Kiarash") >> customers_collection
+        # Both of above ways will call add() method of customers_collection
+        # using second way, you can only add one! but you receive a free tracking instance
+        # which contains information about changes in entity, and entity id.
+        print("A new entity will be added with id:", tracked.key)
+
+    async with customers_collection:
+        async for customer in customers_collection:
+            customers_collection >>= customer
+            # Using above syntax is same as calling: customers_collection.delete(customer)
+            break
+
+        # Again, using below syntax, you can get tracking instance as well.
+        async for customer in customers_collection:
+            tracked = customer << customers_collection
+            print(f"An entity with id {tracked.key}, is going to be deleted!")
 
     # NOTE: no other kind of shifting are allowed only these four!
     # ---------------------------------------------

src/examples/very_simple.py

@@ -15,16 +15,18 @@ def __init__(self, first_name: str, last_name: Optional[str] = None):
 
 class AppEngine(Engine):
     __db_path__ = "__test_db__"
-
     students = Engine.set(Student)
 
 
 async def main():
 
     engine = AppEngine()
 
-    engine.students.add(Student("John", "Doe"))
-    await engine.save_changes_async()
+    async with engine.students as students:
+        students.add_range(Student("John", "Doe"), Student("Jane", "Doe"))
+
+    async for student in engine.students:
+        print(student.first_name, student.last_name)
 
 
 if __name__ == "__main__":

src/sjd/database/_collection.py

@@ -143,20 +143,15 @@ def __init__(self, engine: "Engine", /) -> None:
         self._engine = engine
 
         self._main_file_lock = asyncio.Lock()
-        self._main_iter_ctx: Optional[
-            _CollectionQueryableContext[_TMasterEntity, _TKey, T]
-        ] = None
         self._entity_trackers: dict[_TKey, _EntityTracker[_TKey, T]] = {}
 
     async def __aenter__(self):
-        self._main_iter_ctx = self.get_queryable()
-        return self._main_iter_ctx
+        """Enters a context that will save all changes when it is closed."""
+        return self
 
-    async def __aexit__(self, exc_type: Any, exc_val: Any, exc_tb: Any):
-        if self._main_iter_ctx is not None:
-            if not self._main_iter_ctx.closed:
-                await self._main_iter_ctx.close()
-            self._main_iter_ctx = None
+    async def __aexit__(self, exc_type, exc_val, exc_tb):
+        """Saves all changes made to the collection."""
+        await self.save_changes_async()
 
     async def __aiter__(self):
         async with self.get_queryable() as tmp_file:
@@ -706,7 +701,7 @@ async def count_async(self) -> int:
         """Count the number of entities in the collection."""
 
         await self._ensure_collection_exists()
-        async with self as iter_ctx:
+        async with self.get_queryable() as iter_ctx:
             count = 0
             async for _ in iter_ctx.iter_lines():
                 count += 1