Added an example for app decorators

README.md

@@ -148,3 +148,62 @@ app = VersionedFastAPI(app,
     ]
 )
 ```
+
+
+## APP Decorators
+
+All app decorators should be decalared after creating a Versioned Fast API object
+
+```python
+from fastapi import FastAPI, Request, Response
+from fastapi_versioning import VersionedFastAPI, version
+from starlette.middleware import Middleware
+from starlette.middleware.sessions import SessionMiddleware
+
+app = FastAPI(
+    title='My App',
+    description='Greet uses with a nice message',
+    middleware=[
+        Middleware(SessionMiddleware, secret_key='mysecretkey')
+    ]
+)
+
+@app.get('/greet')
+@version(1)
+def greet(request: Request):
+    request.session['last_version_used'] = 1
+    return 'Hello'
+
+@app.get('/greet')
+@version(2)
+def greet(request: Request):
+    request.session['last_version_used'] = 2
+    return 'Hi'
+
+@app.get('/version')
+def last_version(request: Request):
+    return f'Your last greeting was sent from version {request.session["last_version_used"]}'
+
+app = VersionedFastAPI(app,
+    version_format='{major}',
+    prefix_format='/v{major}',
+    description='Greet users with a nice message',
+    middleware=[
+        Middleware(SessionMiddleware, secret_key='mysecretkey')
+    ]
+)
+
+#Startup event
+@app.on_event("startup")
+async def startup_db_client():
+    print("This runs on app Startup")
+
+#Custom Middlware
+@app.middleware("http")
+async def get_headers(request: Request, call_next):
+    from time import process_time
+    start = process_time()
+    response: Response = await call_next(request)
+    response.headers["X-Process-Time"] = str(process_time() - start)
+    return response
+```