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|
# First install fastapi and uvicorn:
#
# pip install fastapi uvicorn
#
# then run:
#
# uvicorn fastapi_async:app --reload
import logging
from fastapi import FastAPI, HTTPException
from fastapi.responses import HTMLResponse
from gql import Client, gql
from gql.client import ReconnectingAsyncClientSession
from gql.transport.aiohttp import AIOHTTPTransport
logging.basicConfig(level=logging.DEBUG)
log = logging.getLogger(__name__)
transport = AIOHTTPTransport(url="https://countries.trevorblades.com/graphql")
client = Client(transport=transport)
query = gql(
"""
query getContinentInfo($code: ID!) {
continent(code:$code) {
name
code
countries {
name
capital
}
}
}
"""
)
app = FastAPI()
@app.on_event("startup")
async def startup_event():
print("Connecting to GraphQL backend")
await client.connect_async(reconnecting=True)
print("End of startup")
@app.on_event("shutdown")
async def shutdown_event():
print("Shutting down GraphQL permanent connection...")
await client.close_async()
print("Shutting down GraphQL permanent connection... done")
continent_codes = [
"AF",
"AN",
"AS",
"EU",
"NA",
"OC",
"SA",
]
@app.get("/", response_class=HTMLResponse)
def get_root():
continent_links = ", ".join(
[f'<a href="continent/{code}">{code}</a>' for code in continent_codes]
)
return f"""
<html>
<head>
<title>Continents</title>
</head>
<body>
Continents: {continent_links}
</body>
</html>
"""
@app.get("/continent/{continent_code}")
async def get_continent(continent_code):
if continent_code not in continent_codes:
raise HTTPException(status_code=404, detail="Continent not found")
try:
assert isinstance(client.session, ReconnectingAsyncClientSession)
query.variable_values = {"code": continent_code}
result = await client.session.execute(query)
except Exception as e:
log.debug(f"get_continent Error: {e}")
raise HTTPException(status_code=503, detail="GraphQL backend unavailable")
return result
|
