Fastapi - Failed to load API definition docs due to Form issue - fastapi

Question

#renders login page
#router.get('/login',response_class=HTMLResponse)
def login(request : Request):
return templates.TemplateResponse("login.html", {"request": request})
#creates token upon user validation
#router.post('/login', response_class=HTMLResponse)
def login(request : Request, f: OAuth2PasswordRequestForm = Depends()):
data = generate(f.username,f.password )
if data:
access_token = create_token(data={"sub": f.username})
return templates.TemplateResponse("authenticated.html", {"request": request, "data" : data, "access_token": access_token, "token_type": "bearer"})
<form method="POST">
<h5> Access Site</h5></br>
<input class="input-box" type="username" placeholder="Enter Username" name="username" required><br><br>
<input class="input-box" type="password" placeholder="Enter Password" name="password" required><br><br>
<button class="login_button" type="submit">Login</button><br>
<br>
</form>
File "/usr/local/lib/python3.9/site-packages/fastapi/openapi/utils.py", line 423, in get_openapi
definitions = get_model_definitions(
File "/usr/local/lib/python3.9/site-packages/fastapi/utils.py", line 49, in get_model_definitions
model_name = model_name_map[model]
KeyError: <class 'pydantic.main.Body_login_login_post'>
I am not sure why I cant load the swagerUI api, the site itself runs ok .... if I remove the form then I can get to the docs (removing specifically: f: OAuth2PasswordRequestForm = Depends()). Unfortunately this I need to retrieve login input from html template. See above for traceback.

Answer 1

Your code is incomplete, I don't know how you implemented functions generate, create_token and your router but I've tried with this code and it works, both templates via url and /docs url :
from datetime import datetime, timedelta
from fastapi import Depends, FastAPI, Request
from fastapi.security import OAuth2PasswordRequestForm
from jose import jwt
from fastapi.responses import HTMLResponse
from typing import Union
from fastapi.templating import Jinja2Templates
SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30
app = FastAPI()
templates = Jinja2Templates(directory="templates")
def create_access_token(data: dict, expires_delta: Union[timedelta, None] = None):
to_encode = data.copy()
if expires_delta:
expire = datetime.utcnow() + expires_delta
else:
expire = datetime.utcnow() + timedelta(minutes=15)
to_encode.update({"exp": expire})
encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
return encoded_jwt
#app.get('/login',response_class=HTMLResponse)
def login(request : Request):
return templates.TemplateResponse("login.html", {"request": request})
#creates token upon user validation
#app.post('/login', response_class=HTMLResponse)
def login(request : Request, f: OAuth2PasswordRequestForm = Depends()):
data = {"username": f.username, "password": f.password}
access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
access_token = create_access_token(
data={"sub": f.username}, expires_delta=access_token_expires
)
return templates.TemplateResponse(
"authenticated.html", {"request": request, "data" : data,
"access_token": access_token, "token_type": "bearer"}
)