Exceptions

The bareASGI framework handles the exception of type urllib.error.HTTPError.

The source code for the following example can be found here (and here here with typing).

If the content of the exception is specified it may be either an asynchronous iterator yielding bytes, a string or a bytes.

Here are some examples.

from urllib.error import HTTPError

from bareasgi import Application, text_writer
import bareutils.header as header
import pkg_resources
import uvicorn

def make_url(scope) -> str:
    host = header.find(b'host', scope['headers'], b'unknown').decode()
    return f"{scope['scheme']}://{host}{scope['path']}"

async def index_handler(scope, info, matches, content):
    headers = [
        (b'content-type', b'text/html')
    ]
    return 200, headers, text_writer(info['html'])


async def raise_none_exception(scope, info, matches, content):
    raise HTTPError(
        make_url(scope),
        401,
        None,
        None,
        None
    )

async def raise_text_exception(scope, info, matches, content):
    raise HTTPError(
        make_url(scope),
        401,
        'Unauthorized - text',
        [(b'content-type', b'text/plain')],
        None
    )

async def raise_bytes_exception(scope, info, matches, content):
    raise HTTPError(
        make_url(scope),
        401,
        b'Unauthorized - bytes',
        [(b'content-type', b'text/plain')],
        None
    )


async def raise_writer_exception(scope, info, matches, content):
    raise HTTPError(
        make_url(scope),
        401,
        text_writer('Unauthorized - writer'),
        [(b'content-type', b'text/plain')],
        None
    )

html_filename = pkg_resources.resource_filename(__name__, "server_sent_events.html")
with open(html_filename, 'rt') as file_ptr:
    html = file_ptr.read()

app = Application(info=dict(html=html))
app.http_router.add({'GET'}, '/', index_handler)
app.http_router.add({'GET'}, '/raise_none_exception',raise_none_exception)
app.http_router.add({'GET'}, '/raise_text_exception', raise_text_exception)
app.http_router.add({'GET'}, '/raise_bytes_exception', raise_bytes_exception)
app.http_router.add({'GET'}, '/raise_writer_exception', raise_writer_exception)

uvicorn.run(app, port=9009)