from io import BytesIO
import falcon
from .parser import Parser
class MultipartMiddleware(object):
def __init__(self, parser=None):
self.parser = parser or Parser
def parse(self, stream, environ):
return self.parser(fp=stream, environ=environ)
def parse_field(self, field):
if isinstance(field, list):
return [self.parse_field(subfield) for subfield in field]
# When file name isn't ascii FieldStorage will not consider it.
encoded = field.disposition_options.get('filename*')
if encoded:
# http://stackoverflow.com/a/93688
encoding, filename = encoded.split("''")
field.filename = filename
# FieldStorage will decode the file content by itself when
# file name is encoded, but we need to keep a consistent
# API, so let's go back to bytes.
# WARNING we assume file encoding will be same as filename
# but there is no guaranty.
field.file = BytesIO(field.file.read().encode(encoding))
if getattr(field, 'filename', False):
return field
# This is not a file, thus get flat value (not
# FieldStorage instance).
return field.value
def process_request(self, req, resp, **kwargs):
if 'multipart/form-data' not in (req.content_type or ''):
return
# This must be done to avoid a bug in cgi.FieldStorage.
req.env.setdefault('QUERY_STRING', '')
# To avoid all stream consumption problem which occurs in falcon 1.0.0
# or above.
stream = (req.stream.stream if hasattr(req.stream, 'stream') else
req.stream)
try:
form = self.parse(stream=stream, environ=req.env)
except ValueError as e: # Invalid boundary?
raise falcon.HTTPBadRequest('Error parsing file', str(e))
for key in form:
# TODO: put files in req.files instead when #418 get merged.
req._params[key] = self.parse_field(form[key])
