from __future__ import annotations
import binascii
import codecs
import os
import typing
from io import BytesIO
from .fields import _TYPE_FIELD_VALUE_TUPLE, RequestField
writer = codecs.lookup("utf-8")[3]
_TYPE_FIELDS_SEQUENCE = typing.Sequence[
typing.Union[typing.Tuple[str, _TYPE_FIELD_VALUE_TUPLE], RequestField]
]
_TYPE_FIELDS = typing.Union[
_TYPE_FIELDS_SEQUENCE,
typing.Mapping[str, _TYPE_FIELD_VALUE_TUPLE],
]
def choose_boundary() -> str:
"""
Our embarrassingly-simple replacement for mimetools.choose_boundary.
"""
return binascii.hexlify(os.urandom(16)).decode()
def iter_field_objects(fields: _TYPE_FIELDS) -> typing.Iterable[RequestField]:
"""
Iterate over fields.
Supports list of (k, v) tuples and dicts, and lists of
:class:`~urllib3.fields.RequestField`.
"""
iterable: typing.Iterable[RequestField | tuple[str, _TYPE_FIELD_VALUE_TUPLE]]
if isinstance(fields, typing.Mapping):
iterable = fields.items()
else:
iterable = fields
for field in iterable:
if isinstance(field, RequestField):
yield field
else:
yield RequestField.from_tuples(*field)
def encode_multipart_formdata(
fields: _TYPE_FIELDS, boundary: str | None = None
) -> tuple[bytes, str]:
"""
Encode a dictionary of ``fields`` using the multipart/form-data MIME format.
:param fields:
Dictionary of fields or list of (key, :class:`~urllib3.fields.RequestField`).
Values are processed by :func:`urllib3.fields.RequestField.from_tuples`.
:param boundary:
If not specified, then a random boundary will be generated using
:func:`urllib3.filepost.choose_boundary`.
"""
body = BytesIO()
if boundary is None:
boundary = choose_boundary()
for field in iter_field_objects(fields):
body.write(f"--{boundary}\r\n".encode("latin-1"))
writer(body).write(field.render_headers())
data = field.data
if isinstance(data, int):
data = str(data) # Backwards compatibility
if isinstance(data, str):
writer(body).write(data)
else:
body.write(data)
body.write(b"\r\n")
body.write(f"--{boundary}--\r\n".encode("latin-1"))
content_type = f"multipart/form-data; boundary={boundary}"
return body.getvalue(), content_type
|