How to use middleware with routing in fastapi?
How to use middleware with routing in fastapi?
1 answer
by
mallory_cormier ,
a year ago
@jasen
To use middleware with routing in FastAPI, you need to create a custom middleware class that inherits from Middleware class provided by FastAPI. Then, you can define the logic for the middleware in the __call__ method of the class. Here is an example of how to use middleware with routing in FastAPI:
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from fastapi import FastAPI, Request
from fastapi.responses import JSONResponse
from fastapi.middleware import Middleware
class CustomMiddleware:
def __init__(self, app: FastAPI):
self.app = app
async def __call__(self, request: Request, call_next):
# Add your middleware logic here
print("Middleware executed before request handling")
response = await call_next(request)
# Add your middleware logic here
print("Middleware executed after request handling")
return response
app = FastAPI()
# Add custom middleware to the app
app.add_middleware(Middleware, dispatch=CustomMiddleware)
@app.get('/')
async def root():
return {"message": "Hello World"}
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In this example, we create a custom middleware class CustomMiddleware and define the middleware logic in the __call__ method. We then add the middleware to the FastAPI app using the add_middleware method, passing in the custom middleware class as an argument.
When a request is made to the / endpoint, the middleware logic will be executed before and after the request handling, as specified in the __call__ method of the custom middleware class.