ASGI multipart form handling

asgi-multipart.rst

ASGI multipart/form-data Media Handler Demo

Official documentation: Multipart Forms

1. Install Falcon (3.0+ required for ASGI) and the uvicorn ASGI app server:

   pip install -U "falcon >= 3.0.0"
   pip install uvicorn

2. Run as uvicorn test:app, where test:app is coming from the test.py example below.
3. POST your multipart forms to http://127.0.0.1:8000/submit.

API Extensions

Similarly to ASGI Request/Response classes, the ASGI multipart form interface is kept as close to WSGI as possible, with the following additions (made them for WSGI too):

• BodyPart.data becomes (primarily) BodyPart.get_data(), but the property exists as a convenience alias.
• BodyPart.media becomes (primarily) BodyPart.get_media(), but the property exists as a convenience alias.
• BodyPart.text becomes (primarily) BodyPart.get_text(), but the property exists as a convenience alias.

Pull Request

Feature PR: #1728 -- merged!

test.py

import hashlib

import falcon
import falcon.asgi


class Submissions:

    async def on_get(self, req, resp):
        resp.media = {'status': 'up'}

    async def on_post(self, req, resp):
        if not req.content_type or not req.content_type.startswith(
                falcon.MEDIA_MULTIPART):
            raise falcon.HTTPUnsupportedMediaType(title='Gimme multipart')

        form = await req.get_media()
        parts = []

        async for part in form:
            sha1 = hashlib.sha1()
            async for chunk in part.stream:
                sha1.update(chunk)

            parts.append({
                'content_type': part.content_type,
                'filename': part.filename,
                'name': part.name,
                'secure_filename': part.secure_filename,
                'sha1': sha1.hexdigest(),
            })

        resp.media = parts


app = falcon.asgi.App()
app.add_route('/submit', Submissions())