# 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 dataclasses import dataclass
from textwrap import dedent
from typing import TYPE_CHECKING, Literal, cast, overload
from streamlit.elements.lib.form_utils import current_form_id
from streamlit.elements.lib.layout_utils import (
Height,
LayoutConfig,
WidthWithoutContent,
validate_height,
validate_width,
)
from streamlit.elements.lib.policies import (
check_widget_policies,
maybe_raise_label_warnings,
)
from streamlit.elements.lib.utils import (
Key,
LabelVisibility,
compute_and_register_element_id,
get_label_visibility_proto_value,
to_key,
)
from streamlit.errors import StreamlitAPIException
from streamlit.proto.TextArea_pb2 import TextArea as TextAreaProto
from streamlit.proto.TextInput_pb2 import TextInput as TextInputProto
from streamlit.runtime.metrics_util import gather_metrics
from streamlit.runtime.scriptrunner import ScriptRunContext, get_script_run_ctx
from streamlit.runtime.state import (
WidgetArgs,
WidgetCallback,
WidgetKwargs,
get_session_state,
register_widget,
)
from streamlit.string_util import validate_icon_or_emoji
from streamlit.type_util import SupportsStr
if TYPE_CHECKING:
from streamlit.delta_generator import DeltaGenerator
from streamlit.type_util import SupportsStr
@dataclass
class TextInputSerde:
value: str | None
def deserialize(self, ui_value: str | None) -> str | None:
return ui_value if ui_value is not None else self.value
def serialize(self, v: str | None) -> str | None:
return v
@dataclass
class TextAreaSerde:
value: str | None
def deserialize(self, ui_value: str | None) -> str | None:
return ui_value if ui_value is not None else self.value
def serialize(self, v: str | None) -> str | None:
return v
class TextWidgetsMixin:
@overload
def text_input(
self,
label: str,
value: str = "",
max_chars: int | None = None,
key: Key | None = None,
type: Literal["default", "password"] = "default",
help: str | None = None,
autocomplete: str | None = None,
on_change: WidgetCallback | None = None,
args: WidgetArgs | None = None,
kwargs: WidgetKwargs | None = None,
*, # keyword-only arguments:
placeholder: str | None = None,
disabled: bool = False,
label_visibility: LabelVisibility = "visible",
icon: str | None = None,
width: WidthWithoutContent = "stretch",
) -> str:
pass
@overload
def text_input(
self,
label: str,
value: SupportsStr | None = None,
max_chars: int | None = None,
key: Key | None = None,
type: Literal["default", "password"] = "default",
help: str | None = None,
autocomplete: str | None = None,
on_change: WidgetCallback | None = None,
args: WidgetArgs | None = None,
kwargs: WidgetKwargs | None = None,
*, # keyword-only arguments:
placeholder: str | None = None,
disabled: bool = False,
label_visibility: LabelVisibility = "visible",
icon: str | None = None,
width: WidthWithoutContent = "stretch",
) -> str | None:
pass
@gather_metrics("text_input")
def text_input(
self,
label: str,
value: str | SupportsStr | None = "",
max_chars: int | None = None,
key: Key | None = None,
type: Literal["default", "password"] = "default",
help: str | None = None,
autocomplete: str | None = None,
on_change: WidgetCallback | None = None,
args: WidgetArgs | None = None,
kwargs: WidgetKwargs | None = None,
*, # keyword-only arguments:
placeholder: str | None = None,
disabled: bool = False,
label_visibility: LabelVisibility = "visible",
icon: str | None = None,
width: WidthWithoutContent = "stretch",
) -> str | None:
r"""Display a single-line text input widget.
Parameters
----------
label : str
A short label explaining to the user what this input is for.
The label can optionally contain GitHub-flavored Markdown of the
following types: Bold, Italics, Strikethroughs, Inline Code, Links,
and Images. Images display like icons, with a max height equal to
the font height.
Unsupported Markdown elements are unwrapped so only their children
(text contents) render. Display unsupported elements as literal
characters by backslash-escaping them. E.g.,
``"1\. Not an ordered list"``.
See the ``body`` parameter of |st.markdown|_ for additional,
supported Markdown directives.
For accessibility reasons, you should never set an empty label, but
you can hide it with ``label_visibility`` if needed. In the future,
we may disallow empty labels by raising an exception.
.. |st.markdown| replace:: ``st.markdown``
.. _st.markdown: https://docs.streamlit.io/develop/api-reference/text/st.markdown
value : object or None
The text value of this widget when it first renders. This will be
cast to str internally. If ``None``, will initialize empty and
return ``None`` until the user provides input. Defaults to empty string.
max_chars : int or None
Max number of characters allowed in text input.
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. No two widgets may have the same key.
type : "default" or "password"
The type of the text input. This can be either "default" (for
a regular text input), or "password" (for a text input that
masks the user's typed value). Defaults to "default".
help : str or None
A tooltip that gets displayed next to the widget label. Streamlit
only displays the tooltip when ``label_visibility="visible"``. If
this is ``None`` (default), no tooltip is displayed.
The tooltip can optionally contain GitHub-flavored Markdown,
including the Markdown directives described in the ``body``
parameter of ``st.markdown``.
autocomplete : str
An optional value that will be passed to the element's
autocomplete property. If unspecified, this value will be set to
"new-password" for "password" inputs, and the empty string for
"default" inputs. For more details, see https://developer.mozilla.org/en-US/docs/Web/HTML/Attributes/autocomplete
on_change : callable
An optional callback invoked when this text input'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.
placeholder : str or None
An optional string displayed when the text input is empty. If None,
no text is displayed.
disabled : bool
An optional boolean that disables the text input if set to
``True``. The default is ``False``.
label_visibility : "visible", "hidden", or "collapsed"
The visibility of the label. The default is ``"visible"``. If this
is ``"hidden"``, Streamlit displays an empty spacer instead of the
label, which can help keep the widget aligned with other widgets.
icon : str, None
An optional emoji or icon to display within the input field to the
left of the value. If ``icon`` is ``None`` (default), no icon is
displayed. If ``icon`` is a string, the following options are
valid:
- A single-character emoji. For example, you can set ``icon="🚨"``
or ``icon="🔥"``. Emoji short codes are not supported.
- An icon from the Material Symbols library (rounded style) in the
format ``":material/icon_name:"`` where "icon_name" is the name
of the icon in snake case.
For example, ``icon=":material/thumb_up:"`` will display the
Thumb Up icon. Find additional icons in the `Material Symbols \
`_
font library.
width : "stretch" or int
The width of the text input widget. This can be one of the
following:
- ``"stretch"`` (default): The width of the widget matches the
width of the parent container.
- An integer specifying the width in pixels: The widget has a
fixed width. If the specified width is greater than the width of
the parent container, the width of the widget matches the width
of the parent container.
Returns
-------
str or None
The current value of the text input widget or ``None`` if no value has been
provided by the user.
Example
-------
>>> import streamlit as st
>>>
>>> title = st.text_input("Movie title", "Life of Brian")
>>> st.write("The current movie title is", title)
.. output::
https://doc-text-input.streamlit.app/
height: 260px
"""
ctx = get_script_run_ctx()
return self._text_input(
label=label,
value=value,
max_chars=max_chars,
key=key,
type=type,
help=help,
autocomplete=autocomplete,
on_change=on_change,
args=args,
kwargs=kwargs,
placeholder=placeholder,
disabled=disabled,
label_visibility=label_visibility,
icon=icon,
width=width,
ctx=ctx,
)
def _text_input(
self,
label: str,
value: SupportsStr | None = "",
max_chars: int | None = None,
key: Key | None = None,
type: str = "default",
help: str | None = None,
autocomplete: str | None = None,
on_change: WidgetCallback | None = None,
args: WidgetArgs | None = None,
kwargs: WidgetKwargs | None = None,
*, # keyword-only arguments:
placeholder: str | None = None,
disabled: bool = False,
label_visibility: LabelVisibility = "visible",
icon: str | None = None,
width: WidthWithoutContent = "stretch",
ctx: ScriptRunContext | None = None,
) -> str | None:
key = to_key(key)
check_widget_policies(
self.dg,
key,
on_change,
default_value=None if value == "" else value,
)
maybe_raise_label_warnings(label, label_visibility)
# Make sure value is always string or None:
value = str(value) if value is not None else None
element_id = compute_and_register_element_id(
"text_input",
user_key=key,
form_id=current_form_id(self.dg),
dg=self.dg,
label=label,
value=value,
max_chars=max_chars,
type=type,
help=help,
autocomplete=autocomplete,
placeholder=str(placeholder),
icon=icon,
width=width,
)
session_state = get_session_state().filtered_state
if key is not None and key in session_state and session_state[key] is None:
value = None
text_input_proto = TextInputProto()
text_input_proto.id = element_id
text_input_proto.label = label
if value is not None:
text_input_proto.default = value
text_input_proto.form_id = current_form_id(self.dg)
text_input_proto.disabled = disabled
text_input_proto.label_visibility.value = get_label_visibility_proto_value(
label_visibility
)
if help is not None:
text_input_proto.help = dedent(help)
if max_chars is not None:
text_input_proto.max_chars = max_chars
if placeholder is not None:
text_input_proto.placeholder = str(placeholder)
if icon is not None:
text_input_proto.icon = validate_icon_or_emoji(icon)
if type == "default":
text_input_proto.type = TextInputProto.DEFAULT
elif type == "password":
text_input_proto.type = TextInputProto.PASSWORD
else:
raise StreamlitAPIException(
f"'{type}' is not a valid text_input type. Valid types are 'default' and 'password'."
)
# Marshall the autocomplete param. If unspecified, this will be
# set to "new-password" for password inputs.
if autocomplete is None:
autocomplete = "new-password" if type == "password" else ""
text_input_proto.autocomplete = autocomplete
serde = TextInputSerde(value)
widget_state = register_widget(
text_input_proto.id,
on_change_handler=on_change,
args=args,
kwargs=kwargs,
deserializer=serde.deserialize,
serializer=serde.serialize,
ctx=ctx,
value_type="string_value",
)
if widget_state.value_changed:
if widget_state.value is not None:
text_input_proto.value = widget_state.value
text_input_proto.set_value = True
validate_width(width)
layout_config = LayoutConfig(width=width)
self.dg._enqueue("text_input", text_input_proto, layout_config=layout_config)
return widget_state.value
@overload
def text_area(
self,
label: str,
value: str = "",
height: Height | None = None,
max_chars: int | None = None,
key: Key | None = None,
help: str | None = None,
on_change: WidgetCallback | None = None,
args: WidgetArgs | None = None,
kwargs: WidgetKwargs | None = None,
*, # keyword-only arguments:
placeholder: str | None = None,
disabled: bool = False,
label_visibility: LabelVisibility = "visible",
width: WidthWithoutContent = "stretch",
) -> str:
pass
@overload
def text_area(
self,
label: str,
value: SupportsStr | None = None,
height: Height | None = None,
max_chars: int | None = None,
key: Key | None = None,
help: str | None = None,
on_change: WidgetCallback | None = None,
args: WidgetArgs | None = None,
kwargs: WidgetKwargs | None = None,
*, # keyword-only arguments:
placeholder: str | None = None,
disabled: bool = False,
label_visibility: LabelVisibility = "visible",
width: WidthWithoutContent = "stretch",
) -> str | None:
pass
@gather_metrics("text_area")
def text_area(
self,
label: str,
value: str | SupportsStr | None = "",
height: Height | None = None,
max_chars: int | None = None,
key: Key | None = None,
help: str | None = None,
on_change: WidgetCallback | None = None,
args: WidgetArgs | None = None,
kwargs: WidgetKwargs | None = None,
*, # keyword-only arguments:
placeholder: str | None = None,
disabled: bool = False,
label_visibility: LabelVisibility = "visible",
width: WidthWithoutContent = "stretch",
) -> str | None:
r"""Display a multi-line text input widget.
Parameters
----------
label : str
A short label explaining to the user what this input is for.
The label can optionally contain GitHub-flavored Markdown of the
following types: Bold, Italics, Strikethroughs, Inline Code, Links,
and Images. Images display like icons, with a max height equal to
the font height.
Unsupported Markdown elements are unwrapped so only their children
(text contents) render. Display unsupported elements as literal
characters by backslash-escaping them. E.g.,
``"1\. Not an ordered list"``.
See the ``body`` parameter of |st.markdown|_ for additional,
supported Markdown directives.
For accessibility reasons, you should never set an empty label, but
you can hide it with ``label_visibility`` if needed. In the future,
we may disallow empty labels by raising an exception.
.. |st.markdown| replace:: ``st.markdown``
.. _st.markdown: https://docs.streamlit.io/develop/api-reference/text/st.markdown
value : object or None
The text value of this widget when it first renders. This will be
cast to str internally. If ``None``, will initialize empty and
return ``None`` until the user provides input. Defaults to empty string.
height : "content", "stretch", int, or None
The height of the text area widget. This can be one of the
following:
- ``None`` (default): The height of the widget fits three lines.
- ``"content"``: The height of the widget matches the
height of its content.
- ``"stretch"``: The height of the widget matches the height of
its content or the height of the parent container, whichever is
larger. If the widget is not in a parent container, the height
of the widget matches the height of its content.
- An integer specifying the height in pixels: The widget has a
fixed height. If the content is larger than the specified
height, scrolling is enabled.
The widget's height can't be smaller than the height of two lines.
When ``label_visibility="collapsed"``, the minimum height is 68
pixels. Otherwise, the minimum height is 98 pixels.
max_chars : int or None
Maximum number of characters allowed in text area.
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. No two widgets may have the same key.
help : str or None
A tooltip that gets displayed next to the widget label. Streamlit
only displays the tooltip when ``label_visibility="visible"``. If
this is ``None`` (default), no tooltip is displayed.
The tooltip can optionally contain GitHub-flavored Markdown,
including the Markdown directives described in the ``body``
parameter of ``st.markdown``.
on_change : callable
An optional callback invoked when this text_area'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.
placeholder : str or None
An optional string displayed when the text area is empty. If None,
no text is displayed.
disabled : bool
An optional boolean that disables the text area if set to ``True``.
The default is ``False``.
label_visibility : "visible", "hidden", or "collapsed"
The visibility of the label. The default is ``"visible"``. If this
is ``"hidden"``, Streamlit displays an empty spacer instead of the
label, which can help keep the widget aligned with other widgets.
If this is ``"collapsed"``, Streamlit displays no label or spacer.
width : "stretch" or int
The width of the text area widget. This can be one of the
following:
- ``"stretch"`` (default): The width of the widget matches the
width of the parent container.
- An integer specifying the width in pixels: The widget has a
fixed width. If the specified width is greater than the width of
the parent container, the width of the widget matches the width
of the parent container.
Returns
-------
str or None
The current value of the text area widget or ``None`` if no value has been
provided by the user.
Example
-------
>>> import streamlit as st
>>>
>>> txt = st.text_area(
... "Text to analyze",
... "It was the best of times, it was the worst of times, it was the age of "
... "wisdom, it was the age of foolishness, it was the epoch of belief, it "
... "was the epoch of incredulity, it was the season of Light, it was the "
... "season of Darkness, it was the spring of hope, it was the winter of "
... "despair, (...)",
... )
>>>
>>> st.write(f"You wrote {len(txt)} characters.")
.. output::
https://doc-text-area.streamlit.app/
height: 300px
"""
ctx = get_script_run_ctx()
return self._text_area(
label=label,
value=value,
height=height,
max_chars=max_chars,
key=key,
help=help,
on_change=on_change,
args=args,
kwargs=kwargs,
placeholder=placeholder,
disabled=disabled,
label_visibility=label_visibility,
width=width,
ctx=ctx,
)
def _text_area(
self,
label: str,
value: SupportsStr | None = "",
height: Height | None = None,
max_chars: int | None = None,
key: Key | None = None,
help: str | None = None,
on_change: WidgetCallback | None = None,
args: WidgetArgs | None = None,
kwargs: WidgetKwargs | None = None,
*, # keyword-only arguments:
placeholder: str | None = None,
disabled: bool = False,
label_visibility: LabelVisibility = "visible",
width: WidthWithoutContent = "stretch",
ctx: ScriptRunContext | None = None,
) -> str | None:
key = to_key(key)
check_widget_policies(
self.dg,
key,
on_change,
default_value=None if value == "" else value,
)
maybe_raise_label_warnings(label, label_visibility)
value = str(value) if value is not None else None
element_id = compute_and_register_element_id(
"text_area",
user_key=key,
form_id=current_form_id(self.dg),
dg=self.dg,
label=label,
value=value,
height=height,
max_chars=max_chars,
help=help,
placeholder=str(placeholder),
width=width,
)
session_state = get_session_state().filtered_state
if key is not None and key in session_state and session_state[key] is None:
value = None
text_area_proto = TextAreaProto()
text_area_proto.id = element_id
text_area_proto.label = label
if value is not None:
text_area_proto.default = value
text_area_proto.form_id = current_form_id(self.dg)
text_area_proto.disabled = disabled
text_area_proto.label_visibility.value = get_label_visibility_proto_value(
label_visibility
)
if help is not None:
text_area_proto.help = dedent(help)
if max_chars is not None:
text_area_proto.max_chars = max_chars
if placeholder is not None:
text_area_proto.placeholder = str(placeholder)
serde = TextAreaSerde(value)
widget_state = register_widget(
text_area_proto.id,
on_change_handler=on_change,
args=args,
kwargs=kwargs,
deserializer=serde.deserialize,
serializer=serde.serialize,
ctx=ctx,
value_type="string_value",
)
if widget_state.value_changed:
if widget_state.value is not None:
text_area_proto.value = widget_state.value
text_area_proto.set_value = True
validate_width(width)
if height is not None:
validate_height(height, allow_content=True)
else:
# We want to maintain the same approximately three lines of text height
# for the text input when the label is collapsed.
# These numbers are for the entire element including the label and
# padding.
height = 122 if label_visibility != "collapsed" else 94
layout_config = LayoutConfig(width=width, height=height)
self.dg._enqueue("text_area", text_area_proto, layout_config=layout_config)
return widget_state.value
@property
def dg(self) -> DeltaGenerator:
"""Get our DeltaGenerator."""
return cast("DeltaGenerator", self)