49 lines
1.6 KiB
Python
49 lines
1.6 KiB
Python
import asyncio
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from fastapi import FastAPI, Request
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from fastapi.middleware.cors import CORSMiddleware
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from fastapi.responses import StreamingResponse
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from pydantic import BaseModel
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import datetime
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# Use of Pydantic class for automatic request validation in FastAPI
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class Message(BaseModel):
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message: str
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app = FastAPI()
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# This middleware allows other origins to communicate with us
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app.add_middleware(
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CORSMiddleware, # https://developer.mozilla.org/en-US/docs/Web/HTTP/Guides/CORS
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allow_origins=["http://localhost:5173"], # address of our UI application
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allow_methods=["*"], # GET, POST, etc.
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)
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# Endpoint to receive messages from the UI
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@app.post("/message")
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async def receive_message(message: Message):
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"""
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Receives a message from the UI and prints it to the console.
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"""
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print(f"Received message: {message}")
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return { "status": "Message received" }
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# Endpoint for Server-Sent Events (SSE)
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@app.get("/sse")
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async def sse_endpoint(request: Request):
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"""
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Endpoint for Server-Sent Events.
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"""
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async def event_generator():
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while True:
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# If connection to client closes, stop sending events
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if await request.is_disconnected():
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break
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# Send message containing current time every second
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current_time = datetime.datetime.now().strftime("%H:%M:%S")
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yield f"data: Server time: {current_time}\n\n" # \n\n is needed to separate events (SSE is text-based)
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await asyncio.sleep(1)
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return StreamingResponse(event_generator(), media_type="text/event-stream") # media_type specifies that this connection is for event streams
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