team-10/env/Lib/site-packages/streamlit/elements/lib/dialog.py
2025-08-02 07:34:44 +02:00

151 lines
5.3 KiB
Python

# Copyright (c) Streamlit Inc. (2018-2022) Snowflake Inc. (2022-2025)
#
# 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 __future__ import annotations
from typing import TYPE_CHECKING, Literal, cast
from typing_extensions import Self, TypeAlias
from streamlit.delta_generator import DeltaGenerator
from streamlit.errors import StreamlitAPIException
from streamlit.proto.Block_pb2 import Block as BlockProto
from streamlit.proto.ForwardMsg_pb2 import ForwardMsg
from streamlit.runtime.scriptrunner_utils.script_run_context import (
enqueue_message,
get_script_run_ctx,
)
if TYPE_CHECKING:
from types import TracebackType
from streamlit.cursor import Cursor
DialogWidth: TypeAlias = Literal["small", "large"]
def _process_dialog_width_input(
width: DialogWidth,
) -> BlockProto.Dialog.DialogWidth.ValueType:
"""Maps the user-provided literal to a value of the DialogWidth proto enum.
Returns the mapped enum field for "small" by default and otherwise the mapped type.
"""
if width == "large":
return BlockProto.Dialog.DialogWidth.LARGE
return BlockProto.Dialog.DialogWidth.SMALL
def _assert_first_dialog_to_be_opened(should_open: bool) -> None:
"""Check whether a dialog has already been opened in the same script run.
Only one dialog is supposed to be opened. The check is implemented in a way
that for a script run, the open function can only be called once.
One dialog at a time is a product decision and not a technical one.
Raises
------
StreamlitAPIException
Raised when a dialog has already been opened in the current script run.
"""
script_run_ctx = get_script_run_ctx()
# We don't reset the ctx.has_dialog_opened when the flag is False because
# it is reset in a new scriptrun anyways. If the execution model ever changes,
# this might need to change.
if should_open and script_run_ctx:
if script_run_ctx.has_dialog_opened:
raise StreamlitAPIException(
"Only one dialog is allowed to be opened at the same time. "
"Please make sure to not call a dialog-decorated function more than once in a script run."
)
script_run_ctx.has_dialog_opened = True
class Dialog(DeltaGenerator):
@staticmethod
def _create(
parent: DeltaGenerator,
title: str,
*,
dismissible: bool = True,
width: DialogWidth = "small",
) -> Dialog:
block_proto = BlockProto()
block_proto.dialog.title = title
block_proto.dialog.dismissible = dismissible
block_proto.dialog.width = _process_dialog_width_input(width)
# We store the delta path here, because in _update we enqueue a new proto
# message to update the open status. Without this, the dialog content is gone
# when the _update message is sent
delta_path: list[int] = (
parent._active_dg._cursor.delta_path if parent._active_dg._cursor else []
)
dialog = cast("Dialog", parent._block(block_proto=block_proto, dg_type=Dialog))
dialog._delta_path = delta_path
dialog._current_proto = block_proto
return dialog
def __init__(
self,
root_container: int | None,
cursor: Cursor | None,
parent: DeltaGenerator | None,
block_type: str | None,
) -> None:
super().__init__(root_container, cursor, parent, block_type)
# Initialized in `_create()`:
self._current_proto: BlockProto | None = None
self._delta_path: list[int] | None = None
def _update(self, should_open: bool) -> None:
"""Send an updated proto message to indicate the open-status for the dialog."""
if self._current_proto is None or self._delta_path is None:
raise RuntimeError(
"Dialog not correctly initialized. This should never happen."
)
_assert_first_dialog_to_be_opened(should_open)
msg = ForwardMsg()
msg.metadata.delta_path[:] = self._delta_path
msg.delta.add_block.CopyFrom(self._current_proto)
msg.delta.add_block.dialog.is_open = should_open
self._current_proto = msg.delta.add_block
enqueue_message(msg)
def open(self) -> None:
self._update(True)
def close(self) -> None:
self._update(False)
def __enter__(self) -> Self: # type: ignore[override]
# This is a little dubious: we're returning a different type than
# our superclass' `__enter__` function. Maybe DeltaGenerator.__enter__
# should always return `self`?
super().__enter__()
return self
def __exit__(
self,
exc_type: type[BaseException] | None,
exc_val: BaseException | None,
exc_tb: TracebackType | None,
) -> Literal[False]:
return super().__exit__(exc_type, exc_val, exc_tb)