Error Handlers & Custom Exceptions ¶

Define Custom Exceptions ¶

class NotFound(Exception):
    pass

class ValidationError(Exception):
    pass

class UnauthorizedError(Exception):
    pass

Register Exception Handlers ¶

from stario import Stario
from stario.html import html, h1, p
from stario.responses import PlainTextResponse

app = Stario()

async def handle_not_found(request, exc):
    return PlainTextResponse("Not Found", status_code=404)

async def handle_validation(request, exc):
    return PlainTextResponse("Validation Error", status_code=400)

async def handle_unauthorized(request, exc):
    return PlainTextResponse("Unauthorized", status_code=401)

app.add_exception_handler(NotFound, handle_not_found)
app.add_exception_handler(ValidationError, handle_validation)
app.add_exception_handler(UnauthorizedError, handle_unauthorized)

Raise in Endpoints ¶

from stario import Query
from stario.html import html, head, body, h1

@app.query("/users/{user_id}")
async def get_user(user_id: int):
    user = db.find_user(user_id)
    if not user:
        raise NotFound(f"User {user_id} not found")

    return html(
        head(),
        body(
            h1(user.name),
            p(user.email),
        )
    )