2022-05-23 00:16:32 +04:00

398 lines
14 KiB
Python

# Copyright 2018-2022 Streamlit Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from streamlit.type_util import Key, to_key
from typing import cast, overload, List, Optional, Union
from textwrap import dedent
import sys
if sys.version_info >= (3, 8):
from typing import Literal
else:
from typing_extensions import Literal
import streamlit
from streamlit import config
from streamlit.logger import get_logger
from streamlit.proto.FileUploader_pb2 import FileUploader as FileUploaderProto
from streamlit.scriptrunner import ScriptRunContext, get_script_run_ctx
from streamlit.state import (
register_widget,
WidgetArgs,
WidgetCallback,
WidgetKwargs,
)
from .form import current_form_id
from ..proto.Common_pb2 import (
FileUploaderState as FileUploaderStateProto,
UploadedFileInfo as UploadedFileInfoProto,
)
from ..uploaded_file_manager import UploadedFile, UploadedFileRec
from .utils import check_callback_rules, check_session_state_rules
LOGGER = get_logger(__name__)
SomeUploadedFiles = Optional[Union[UploadedFile, List[UploadedFile]]]
class FileUploaderMixin:
# Multiple overloads are defined on `file_uploader()` below to represent
# the different return types of `file_uploader()`.
# These return types differ according to the value of the `accept_multiple_files` argument.
# There are 2 associated variables, each with 2 options.
# 1. The `accept_multiple_files` argument is set as `True`,
# or it is set as `False` or omitted, in which case the default value `False`.
# 2. The `type` argument may or may not be provided as a keyword-only argument.
# There must be 2x2=4 overloads to cover all the possible arguments,
# as these overloads must be mutually exclusive for mypy.
# 1. type is given as not a keyword-only argument
# 2. accept_multiple_files = True
@overload
def file_uploader(
self,
label: str,
type: Optional[Union[str, List[str]]],
accept_multiple_files: Literal[True],
key: Optional[Key] = None,
help: Optional[str] = None,
on_change: Optional[WidgetCallback] = None,
args: Optional[WidgetArgs] = None,
kwargs: Optional[WidgetKwargs] = None,
*,
disabled: bool = False,
) -> Optional[List[UploadedFile]]:
...
# 1. type is given as not a keyword-only argument
# 2. accept_multiple_files = False or omitted
@overload
def file_uploader(
self,
label: str,
type: Optional[Union[str, List[str]]],
accept_multiple_files: Literal[False] = False,
key: Optional[Key] = None,
help: Optional[str] = None,
on_change: Optional[WidgetCallback] = None,
args: Optional[WidgetArgs] = None,
kwargs: Optional[WidgetKwargs] = None,
*,
disabled: bool = False,
) -> Optional[UploadedFile]:
...
# The following 2 overloads represent the cases where
# the `type` argument is a keyword-only argument.
# See https://github.com/python/mypy/issues/4020#issuecomment-737600893
# for the related discussions and examples.
# 1. type is skipped or a keyword argument
# 2. accept_multiple_files = True
@overload
def file_uploader(
self,
label: str,
*,
accept_multiple_files: Literal[True],
type: Optional[Union[str, List[str]]] = None,
key: Optional[Key] = None,
help: Optional[str] = None,
on_change: Optional[WidgetCallback] = None,
args: Optional[WidgetArgs] = None,
kwargs: Optional[WidgetKwargs] = None,
disabled: bool = False,
) -> Optional[List[UploadedFile]]:
...
# 1. type is skipped or a keyword argument
# 2. accept_multiple_files = False or omitted
@overload
def file_uploader(
self,
label: str,
*,
accept_multiple_files: Literal[False] = False,
type: Optional[Union[str, List[str]]] = None,
key: Optional[Key] = None,
help: Optional[str] = None,
on_change: Optional[WidgetCallback] = None,
args: Optional[WidgetArgs] = None,
kwargs: Optional[WidgetKwargs] = None,
disabled: bool = False,
) -> Optional[UploadedFile]:
...
def file_uploader(
self,
label: str,
type: Optional[Union[str, List[str]]] = None,
accept_multiple_files: bool = False,
key: Optional[Key] = None,
help: Optional[str] = None,
on_change: Optional[WidgetCallback] = None,
args: Optional[WidgetArgs] = None,
kwargs: Optional[WidgetKwargs] = None,
*, # keyword-only arguments:
disabled: bool = False,
):
"""Display a file uploader widget.
By default, uploaded files are limited to 200MB. You can configure
this using the `server.maxUploadSize` config option. For more info
on how to set config options, see
https://docs.streamlit.io/library/advanced-features/configuration#set-configuration-options
Parameters
----------
label : str
A short label explaining to the user what this file uploader is for.
type : str or list of str or None
Array of allowed extensions. ['png', 'jpg']
The default is None, which means all extensions are allowed.
accept_multiple_files : bool
If True, allows the user to upload multiple files at the same time,
in which case the return value will be a list of files.
Default: False
key : str or int
An optional string or integer to use as the unique key for the widget.
If this is omitted, a key will be generated for the widget
based on its content. Multiple widgets of the same type may
not share the same key.
help : str
A tooltip that gets displayed next to the file uploader.
on_change : callable
An optional callback invoked when this file_uploader's value
changes.
args : tuple
An optional tuple of args to pass to the callback.
kwargs : dict
An optional dict of kwargs to pass to the callback.
disabled : bool
An optional boolean, which disables the file uploader if set to
True. The default is False. This argument can only be supplied by
keyword.
Returns
-------
None or UploadedFile or list of UploadedFile
- If accept_multiple_files is False, returns either None or
an UploadedFile object.
- If accept_multiple_files is True, returns a list with the
uploaded files as UploadedFile objects. If no files were
uploaded, returns an empty list.
The UploadedFile class is a subclass of BytesIO, and therefore
it is "file-like". This means you can pass them anywhere where
a file is expected.
Examples
--------
Insert a file uploader that accepts a single file at a time:
>>> uploaded_file = st.file_uploader("Choose a file")
>>> if uploaded_file is not None:
... # To read file as bytes:
... bytes_data = uploaded_file.getvalue()
... st.write(bytes_data)
>>>
... # To convert to a string based IO:
... stringio = StringIO(uploaded_file.getvalue().decode("utf-8"))
... st.write(stringio)
>>>
... # To read file as string:
... string_data = stringio.read()
... st.write(string_data)
>>>
... # Can be used wherever a "file-like" object is accepted:
... dataframe = pd.read_csv(uploaded_file)
... st.write(dataframe)
Insert a file uploader that accepts multiple files at a time:
>>> uploaded_files = st.file_uploader("Choose a CSV file", accept_multiple_files=True)
>>> for uploaded_file in uploaded_files:
... bytes_data = uploaded_file.read()
... st.write("filename:", uploaded_file.name)
... st.write(bytes_data)
.. output::
https://share.streamlit.io/streamlit/docs/main/python/api-examples-source/widget.file_uploader.py
height: 375px
"""
ctx = get_script_run_ctx()
return self._file_uploader(
label=label,
type=type,
accept_multiple_files=accept_multiple_files,
key=key,
help=help,
on_change=on_change,
args=args,
kwargs=kwargs,
disabled=disabled,
ctx=ctx,
)
def _file_uploader(
self,
label: str,
type: Optional[Union[str, List[str]]] = None,
accept_multiple_files: bool = False,
key: Optional[Key] = None,
help: Optional[str] = None,
on_change: Optional[WidgetCallback] = None,
args: Optional[WidgetArgs] = None,
kwargs: Optional[WidgetKwargs] = None,
*, # keyword-only arguments:
disabled: bool = False,
ctx: Optional[ScriptRunContext] = None,
):
key = to_key(key)
check_callback_rules(self.dg, on_change)
check_session_state_rules(default_value=None, key=key, writes_allowed=False)
if type:
if isinstance(type, str):
type = [type]
# May need a regex or a library to validate file types are valid
# extensions.
type = [
file_type if file_type[0] == "." else f".{file_type}"
for file_type in type
]
file_uploader_proto = FileUploaderProto()
file_uploader_proto.label = label
file_uploader_proto.type[:] = type if type is not None else []
file_uploader_proto.max_upload_size_mb = config.get_option(
"server.maxUploadSize"
)
file_uploader_proto.multiple_files = accept_multiple_files
file_uploader_proto.form_id = current_form_id(self.dg)
if help is not None:
file_uploader_proto.help = dedent(help)
def deserialize_file_uploader(
ui_value: Optional[FileUploaderStateProto], widget_id: str
) -> SomeUploadedFiles:
file_recs = self._get_file_recs(widget_id, ui_value)
if len(file_recs) == 0:
return_value: Optional[Union[List[UploadedFile], UploadedFile]] = (
[] if accept_multiple_files else None
)
else:
files = [UploadedFile(rec) for rec in file_recs]
return_value = files if accept_multiple_files else files[0]
return return_value
def serialize_file_uploader(files: SomeUploadedFiles) -> FileUploaderStateProto:
state_proto = FileUploaderStateProto()
ctx = get_script_run_ctx()
if ctx is None:
return state_proto
# ctx.uploaded_file_mgr._file_id_counter stores the id to use for
# the *next* uploaded file, so the current highest file id is the
# counter minus 1.
state_proto.max_file_id = ctx.uploaded_file_mgr._file_id_counter - 1
if not files:
return state_proto
elif not isinstance(files, list):
files = [files]
for f in files:
file_info: UploadedFileInfoProto = state_proto.uploaded_file_info.add()
file_info.id = f.id
file_info.name = f.name
file_info.size = f.size
return state_proto
# FileUploader's widget value is a list of file IDs
# representing the current set of files that this uploader should
# know about.
widget_value, _ = register_widget(
"file_uploader",
file_uploader_proto,
user_key=key,
on_change_handler=on_change,
args=args,
kwargs=kwargs,
deserializer=deserialize_file_uploader,
serializer=serialize_file_uploader,
ctx=ctx,
)
# This needs to be done after register_widget because we don't want
# the following proto fields to affect a widget's ID.
file_uploader_proto.disabled = disabled
file_uploader_state = serialize_file_uploader(widget_value)
uploaded_file_info = file_uploader_state.uploaded_file_info
if ctx is not None and len(uploaded_file_info) != 0:
newest_file_id = file_uploader_state.max_file_id
active_file_ids = [f.id for f in uploaded_file_info]
ctx.uploaded_file_mgr.remove_orphaned_files(
session_id=ctx.session_id,
widget_id=file_uploader_proto.id,
newest_file_id=newest_file_id,
active_file_ids=active_file_ids,
)
self.dg._enqueue("file_uploader", file_uploader_proto)
return cast(SomeUploadedFiles, widget_value)
@staticmethod
def _get_file_recs(
widget_id: str, widget_value: Optional[FileUploaderStateProto]
) -> List[UploadedFileRec]:
if widget_value is None:
return []
ctx = get_script_run_ctx()
if ctx is None:
return []
uploaded_file_info = widget_value.uploaded_file_info
if len(uploaded_file_info) == 0:
return []
active_file_ids = [f.id for f in uploaded_file_info]
# Grab the files that correspond to our active file IDs.
return ctx.uploaded_file_mgr.get_files(
session_id=ctx.session_id,
widget_id=widget_id,
file_ids=active_file_ids,
)
@property
def dg(self) -> "streamlit.delta_generator.DeltaGenerator":
"""Get our DeltaGenerator."""
return cast("streamlit.delta_generator.DeltaGenerator", self)