[WIP] Update on_event with lifespan event handler in docs

docs/tutorial/fastapi/simple-hero-api.md

@@ -159,7 +159,7 @@ And then create an `app` object that is an instance of that `FastAPI` class:
 
 We want to make sure that once the app starts running, the function `create_tables` is called. To create the database and tables.
 
-This should be called only once at startup, not before every request, so we put it in the function to handle the `"startup"` event:
+This should be called only once at startup, not before every request. We define this startup logic using the lifespan parameter of the FastAPI app. The input for this parameter is an async function lifespan() which yields after calling `create_db_and_tables`.
 
 //// tab | Python 3.10+
 

docs_src/tutorial/fastapi/app_testing/tutorial001/main.py

@@ -1,3 +1,4 @@
+from contextlib import asynccontextmanager
 from typing import List, Optional
 
 from fastapi import Depends, FastAPI, HTTPException, Query
@@ -44,12 +45,13 @@ def get_session():
         yield session
 
 
-app = FastAPI()
+@asynccontextmanager
+async def lifespan(app: FastAPI):
+    create_db_and_tables()
+    yield
 
 
-@app.on_event("startup")
-def on_startup():
-    create_db_and_tables()
+app = FastAPI(lifespan=lifespan)
 
 
 @app.post("/heroes/", response_model=HeroPublic)

docs_src/tutorial/fastapi/app_testing/tutorial001_py310/main.py

@@ -1,3 +1,5 @@
+from contextlib import asynccontextmanager
+
 from fastapi import Depends, FastAPI, HTTPException, Query
 from sqlmodel import Field, Session, SQLModel, create_engine, select
 
@@ -42,12 +44,13 @@ def get_session():
         yield session
 
 
-app = FastAPI()
+@asynccontextmanager
+async def lifespan(app: FastAPI):
+    create_db_and_tables()
+    yield
 
 
-@app.on_event("startup")
-def on_startup():
-    create_db_and_tables()
+app = FastAPI(lifespan=lifespan)
 
 
 @app.post("/heroes/", response_model=HeroPublic)

docs_src/tutorial/fastapi/app_testing/tutorial001_py39/main.py

@@ -1,3 +1,4 @@
+from contextlib import asynccontextmanager
 from typing import Optional
 
 from fastapi import Depends, FastAPI, HTTPException, Query
@@ -44,12 +45,13 @@ def get_session():
         yield session
 
 
-app = FastAPI()
+@asynccontextmanager
+async def lifespan(app: FastAPI):
+    create_db_and_tables()
+    yield
 
 
-@app.on_event("startup")
-def on_startup():
-    create_db_and_tables()
+app = FastAPI(lifespan=lifespan)
 
 
 @app.post("/heroes/", response_model=HeroPublic)

docs_src/tutorial/fastapi/delete/tutorial001.py

@@ -1,3 +1,4 @@
+from contextlib import asynccontextmanager
 from typing import List, Optional
 
 from fastapi import FastAPI, HTTPException, Query
@@ -39,12 +40,13 @@ def create_db_and_tables():
     SQLModel.metadata.create_all(engine)
 
 
-app = FastAPI()
+@asynccontextmanager
+async def lifespan(app: FastAPI):
+    create_db_and_tables()
+    yield
 
 
-@app.on_event("startup")
-def on_startup():
-    create_db_and_tables()
+app = FastAPI(lifespan=lifespan)
 
 
 @app.post("/heroes/", response_model=HeroPublic)

docs_src/tutorial/fastapi/delete/tutorial001_py310.py

@@ -1,3 +1,5 @@
+from contextlib import asynccontextmanager
+
 from fastapi import FastAPI, HTTPException, Query
 from sqlmodel import Field, Session, SQLModel, create_engine, select
 
@@ -37,12 +39,13 @@ def create_db_and_tables():
     SQLModel.metadata.create_all(engine)
 
 
-app = FastAPI()
+@asynccontextmanager
+async def lifespan(app: FastAPI):
+    create_db_and_tables()
+    yield
 
 
-@app.on_event("startup")
-def on_startup():
-    create_db_and_tables()
+app = FastAPI(lifespan=lifespan)
 
 
 @app.post("/heroes/", response_model=HeroPublic)

docs_src/tutorial/fastapi/delete/tutorial001_py39.py

@@ -1,3 +1,4 @@
+from contextlib import asynccontextmanager
 from typing import Optional
 
 from fastapi import FastAPI, HTTPException, Query
@@ -39,12 +40,13 @@ def create_db_and_tables():
     SQLModel.metadata.create_all(engine)
 
 
-app = FastAPI()
+@asynccontextmanager
+async def lifespan(app: FastAPI):
+    create_db_and_tables()
+    yield
 
 
-@app.on_event("startup")
-def on_startup():
-    create_db_and_tables()
+app = FastAPI(lifespan=lifespan)
 
 
 @app.post("/heroes/", response_model=HeroPublic)

docs_src/tutorial/fastapi/limit_and_offset/tutorial001.py

@@ -1,3 +1,4 @@
+from contextlib import asynccontextmanager
 from typing import List, Optional
 
 from fastapi import FastAPI, HTTPException, Query
@@ -33,12 +34,13 @@ def create_db_and_tables():
     SQLModel.metadata.create_all(engine)
 
 
-app = FastAPI()
+@asynccontextmanager
+async def lifespan(app: FastAPI):
+    create_db_and_tables()
+    yield
 
 
-@app.on_event("startup")
-def on_startup():
-    create_db_and_tables()
+app = FastAPI(lifespan=lifespan)
 
 
 @app.post("/heroes/", response_model=HeroPublic)

docs_src/tutorial/fastapi/limit_and_offset/tutorial001_py310.py

@@ -1,3 +1,5 @@
+from contextlib import asynccontextmanager
+
 from fastapi import FastAPI, HTTPException, Query
 from sqlmodel import Field, Session, SQLModel, create_engine, select
 
@@ -31,12 +33,13 @@ def create_db_and_tables():
     SQLModel.metadata.create_all(engine)
 
 
-app = FastAPI()
+@asynccontextmanager
+async def lifespan(app: FastAPI):
+    create_db_and_tables()
+    yield
 
 
-@app.on_event("startup")
-def on_startup():
-    create_db_and_tables()
+app = FastAPI(lifespan=lifespan)
 
 
 @app.post("/heroes/", response_model=HeroPublic)

docs_src/tutorial/fastapi/limit_and_offset/tutorial001_py39.py

@@ -1,3 +1,4 @@
+from contextlib import asynccontextmanager
 from typing import Optional
 
 from fastapi import FastAPI, HTTPException, Query
@@ -33,12 +34,13 @@ def create_db_and_tables():
     SQLModel.metadata.create_all(engine)
 
 
-app = FastAPI()
+@asynccontextmanager
+async def lifespan(app: FastAPI):
+    create_db_and_tables()
+    yield
 
 
-@app.on_event("startup")
-def on_startup():
-    create_db_and_tables()
+app = FastAPI(lifespan=lifespan)
 
 
 @app.post("/heroes/", response_model=HeroPublic)

docs_src/tutorial/fastapi/multiple_models/tutorial001.py

@@ -1,3 +1,4 @@
+from contextlib import asynccontextmanager
 from typing import List, Optional
 
 from fastapi import FastAPI
@@ -35,12 +36,13 @@ def create_db_and_tables():
     SQLModel.metadata.create_all(engine)
 
 
-app = FastAPI()
+@asynccontextmanager
+async def lifespan(app: FastAPI):
+    create_db_and_tables()
+    yield
 
 
-@app.on_event("startup")
-def on_startup():
-    create_db_and_tables()
+app = FastAPI(lifespan=lifespan)
 
 
 @app.post("/heroes/", response_model=HeroPublic)

docs_src/tutorial/fastapi/multiple_models/tutorial001_py310.py

@@ -1,3 +1,5 @@
+from contextlib import asynccontextmanager
+
 from fastapi import FastAPI
 from sqlmodel import Field, Session, SQLModel, create_engine, select
 
@@ -33,12 +35,13 @@ def create_db_and_tables():
     SQLModel.metadata.create_all(engine)
 
 
-app = FastAPI()
+@asynccontextmanager
+async def lifespan(app: FastAPI):
+    create_db_and_tables()
+    yield
 
 
-@app.on_event("startup")
-def on_startup():
-    create_db_and_tables()
+app = FastAPI(lifespan=lifespan)
 
 
 @app.post("/heroes/", response_model=HeroPublic)

docs_src/tutorial/fastapi/multiple_models/tutorial001_py39.py

@@ -1,3 +1,4 @@
+from contextlib import asynccontextmanager
 from typing import Optional
 
 from fastapi import FastAPI
@@ -35,12 +36,13 @@ def create_db_and_tables():
     SQLModel.metadata.create_all(engine)
 
 
-app = FastAPI()
+@asynccontextmanager
+async def lifespan(app: FastAPI):
+    create_db_and_tables()
+    yield
 
 
-@app.on_event("startup")
-def on_startup():
-    create_db_and_tables()
+app = FastAPI(lifespan=lifespan)
 
 
 @app.post("/heroes/", response_model=HeroPublic)

docs_src/tutorial/fastapi/multiple_models/tutorial002.py

@@ -1,3 +1,4 @@
+from contextlib import asynccontextmanager
 from typing import List, Optional
 
 from fastapi import FastAPI
@@ -33,12 +34,13 @@ def create_db_and_tables():
     SQLModel.metadata.create_all(engine)
 
 
-app = FastAPI()
+@asynccontextmanager
+async def lifespan(app: FastAPI):
+    create_db_and_tables()
+    yield
 
 
-@app.on_event("startup")
-def on_startup():
-    create_db_and_tables()
+app = FastAPI(lifespan=lifespan)
 
 
 @app.post("/heroes/", response_model=HeroPublic)

docs_src/tutorial/fastapi/multiple_models/tutorial002_py310.py

@@ -1,3 +1,5 @@
+from contextlib import asynccontextmanager
+
 from fastapi import FastAPI
 from sqlmodel import Field, Session, SQLModel, create_engine, select
 
@@ -31,12 +33,13 @@ def create_db_and_tables():
     SQLModel.metadata.create_all(engine)
 
 
-app = FastAPI()
+@asynccontextmanager
+async def lifespan(app: FastAPI):
+    create_db_and_tables()
+    yield
 
 
-@app.on_event("startup")
-def on_startup():
-    create_db_and_tables()
+app = FastAPI(lifespan=lifespan)
 
 
 @app.post("/heroes/", response_model=HeroPublic)

docs_src/tutorial/fastapi/multiple_models/tutorial002_py39.py

@@ -1,3 +1,4 @@
+from contextlib import asynccontextmanager
 from typing import Optional
 
 from fastapi import FastAPI
@@ -33,12 +34,13 @@ def create_db_and_tables():
     SQLModel.metadata.create_all(engine)
 
 
-app = FastAPI()
+@asynccontextmanager
+async def lifespan(app: FastAPI):
+    create_db_and_tables()
+    yield
 
 
-@app.on_event("startup")
-def on_startup():
-    create_db_and_tables()
+app = FastAPI(lifespan=lifespan)
 
 
 @app.post("/heroes/", response_model=HeroPublic)

docs_src/tutorial/fastapi/read_one/tutorial001.py

@@ -1,3 +1,4 @@
+from contextlib import asynccontextmanager
 from typing import List, Optional
 
 from fastapi import FastAPI, HTTPException
@@ -33,12 +34,13 @@ def create_db_and_tables():
     SQLModel.metadata.create_all(engine)
 
 
-app = FastAPI()
+@asynccontextmanager
+async def lifespan(app: FastAPI):
+    create_db_and_tables()
+    yield
 
 
-@app.on_event("startup")
-def on_startup():
-    create_db_and_tables()
+app = FastAPI(lifespan=lifespan)
 
 
 @app.post("/heroes/", response_model=HeroPublic)