Shiny Express API

This page outlines Shiny Express’s API reference.

Compared to Shiny Core, Shiny Express is a simpler way to learn and create basic apps, but it is less flexible and powerful.

For an introduction to Shiny, see the tutorial.

Function reference

Input components

Gather user input.

express.ui.input_select	Create a select list that can be used to choose a single or multiple items from a list of values.
express.ui.input_selectize	Create a select list that can be used to choose a single or multiple items from a list of values.
express.ui.input_slider	Constructs a slider widget to select a number, date, or date-time from a range.
express.ui.input_dark_mode	Creates a dark mode switch input that toggles the app between dark and light modes.
express.ui.input_date	Creates a text input which, when clicked on, brings up a calendar that the user can click on to select dates.
express.ui.input_date_range	Creates a pair of text inputs which, when clicked on, bring up calendars that the user can click on to select dates.
express.ui.input_checkbox	Create a checkbox that can be used to specify logical values.
express.ui.input_checkbox_group	Create a group of checkboxes that can be used to toggle multiple choices independently.
express.ui.input_switch	Create a switch that can be used to specify logical values. Similar to input_checkbox, but implies to the user that the change will take effect immediately.
express.ui.input_radio_buttons	Create a set of radio buttons used to select an item from a list.
express.ui.input_numeric	Create an input control for entry of numeric values.
express.ui.input_text	Create an input control for entry of text values.
express.ui.input_text_area	Create a textarea input control for entry of unstructured text values.
express.ui.input_password	Create an password control for entry of passwords.
express.ui.input_action_button	Creates an action button whose value is initially zero, and increments by one each time it is pressed.
express.ui.input_action_link	Creates a link whose value is initially zero, and increments by one each time it is pressed.
express.ui.input_task_button	Creates a button for launching longer-running operations.

Output components

Reactively render output.

express.render.plot	Reactively render a plot object as an HTML image.
express.render.table	Reactively render a pandas `DataFrame` object (or similar) as a basic HTML table.
express.render.DataTable	Holds the data and options for a data_frame output, for a spreadsheet-like view.
express.render.data_frame	Decorator for a function that returns a pandas, polars, or eager `narwhals` compatible `DataFrame` object to render as an interactive table or grid. Features fast virtualized scrolling, sorting, filtering, and row selection (single or multiple).
express.render.DataGrid	Holds the data and options for a data_frame output, for a spreadsheet-like view.
express.render.text	Reactively render text.
express.render.ui	Reactively render HTML content.
express.render.download	Decorator to register a function to handle a download.
express.render.image	Reactively render a image file as an HTML image.
express.render.express	Reactively render HTML content with output captured as in Shiny Express

Layouts and other UI tools

Tools for creating, arranging, and styling UI components.

express.ui.page_opts	Set page-level options for the current app.
express.ui.sidebar	Context manager for sidebar element
express.ui.layout_columns	Context manager for responsive, column-based grid layouts, based on a 12-column grid.
express.ui.layout_column_wrap	Context manager for a grid-like, column-first layout
express.ui.card	Context manager for Bootstrap card component
express.ui.card_header	Context manager for a card header container
express.ui.card_footer	Context manager for a card footer container
express.ui.value_box	Context manager for a value box
express.ui.value_box_theme	Value box theme
express.ui.popover	Context manager for a popover
express.ui.tooltip	Context manager for a tooltip
express.ui.accordion	Context manager for a vertically collapsing accordion.
express.ui.accordion_panel	Context manager for single accordion panel.
express.ui.layout_sidebar	Context manager for sidebar layout

Navigate multiple panels

Create a set of panels that can be navigated between.

express.ui.nav_panel	Context manager for nav item pointing to some internal content.
express.ui.navset_card_underline	Context manager for a set of nav items as a tabset inside a card container.
express.ui.navset_card_tab	Context manager for a set of nav items as a tabset inside a card container.
express.ui.navset_card_pill	Context manager for a set of nav items as a tabset inside a card container.
express.ui.nav_spacer	Create space between nav items.
express.ui.nav_menu	Context manager for a menu of nav items.
express.ui.nav_control	Context manager for a control in the navigation container.
express.ui.navset_bar	Context manager for a set of nav items as a tabset inside a card container.
express.ui.navset_tab	Context manager for a set of nav items as a tabset.
express.ui.navset_pill	Context manager for a set of nav items as a pillset.
express.ui.navset_underline	Context manager for a set of nav items whose active/focused navigation links are styled with an underline.
express.ui.navset_pill_list	Context manager for a set of nav items as a tabset inside a card container.
express.ui.navset_hidden	Context manager for nav contents without the nav items.

Chat interface

Build a chatbot interface

express.ui.Chat

Create a chat interface.

Reactive programming

Create reactive functions and dependencies.

reactive.calc	Mark a function as a reactive calculation.
reactive.effect	Mark a function as a reactive side effect.
reactive.value	Create a reactive value.
reactive.event	Mark a function to react only when an “event” occurs.
reactive.isolate	Create a non-reactive scope within a reactive scope.
reactive.invalidate_later	Scheduled Invalidation
reactive.extended_task	Decorator to mark an async function as a slow computation. This will cause the function to be run in a background asyncio task, and the results will be available via the ExtendedTask object returned by the decorator.
reactive.flush	Run any pending invalidations (i.e., flush the reactive environment).
reactive.poll	Create a reactive polling object.
reactive.file_reader	Create a reactive file reader.
reactive.lock	A lock that should be held whenever manipulating the reactive graph.
req	Throw a silent exception for falsy values.

Reusable Express code

Create reusable Express code.

express.ui.hold	Prevent the display of UI elements in various ways.
express.expressify	Decorate a function so that output is captured as in Shiny Express

Update inputs

Programmatically update input values.

express.ui.update_select	Change the value of a select input on the client.
express.ui.update_selectize	Change the value of a selectize.js powered input on the client.
express.ui.update_slider	Change the value of a slider input on the client.
express.ui.update_dark_mode
express.ui.update_date	Change the value of a date input on the client.
express.ui.update_date_range	Change the start and end values of a date range input on the client.
express.ui.update_checkbox	Change the value of a checkbox input on the client.
express.ui.update_checkbox_group	Change the value of a checkbox group input on the client.
express.ui.update_switch	Change the value of a switch input on the client.
express.ui.update_radio_buttons	Change the value of a radio input on the client.
express.ui.update_numeric	Change the value of a number input on the client.
express.ui.update_text	Change the value of a text input on the client.
express.ui.update_text_area	Change the value of a text input on the client.
express.ui.update_navs	Change the value of a navs container on the client.
express.ui.update_action_button	Change the label and/or icon of an action button on the client.
express.ui.update_action_link	Change the label and/or icon of an action link on the client.
express.ui.update_task_button	Change the state of a task button on the client.

Update UI Layouts

express.ui.update_sidebar	Update a sidebar’s visibility.
express.ui.update_tooltip	Update tooltip contents.
express.ui.update_popover	Update the contents or title of a popover.
express.ui.update_accordion	Dynamically set accordions’ states.
express.ui.update_accordion_panel	Dynamically update accordion panel contents.
express.ui.insert_accordion_panel	Insert an accordion_panel.
express.ui.remove_accordion_panel	Remove an accordion_panel.

Display messages

Display messages to the user.

express.ui.help_text	Create a help text element
express.ui.notification_show	Show a notification to the user.
express.ui.notification_remove	Remove a notification.
express.ui.modal	Creates the UI for a modal dialog, using Bootstrap’s modal class.
express.ui.modal_show	Show a modal dialog.
express.ui.modal_remove	Remove a modal dialog box.
express.ui.modal_button	Creates a button that will dismiss a modal.
express.ui.Progress	Initialize a progress bar.

Modules

express.module

Create a Shiny module using Shiny Express syntax

UI panels

Visually group together a section of UI components.

express.ui.panel_absolute	Context manager for a panel of absolutely positioned content.
express.ui.panel_fixed	Context manager for a panel of absolutely positioned content.
express.ui.panel_title	Create title(s) for the application.
express.ui.panel_well	Context manager for a well panel

Uploads & downloads

Allow users to upload and download files.

express.ui.input_file	Create a file upload control that can be used to upload one or more files.
express.render.download	Decorator to register a function to handle a download.

Dynamic UI

Dynamically show/hide UI elements.

express.ui.panel_conditional	Context manager for a conditional panel
express.ui.insert_ui	Insert UI objects.
express.ui.remove_ui	Remove UI objects.

UI as HTML

Tools for creating HTML/CSS/JS

express.ui.Theme	Create a custom Shiny theme.
express.ui.markdown	Convert a string of markdown to `ui.HTML`.
express.ui.include_css	Include a CSS file.
express.ui.include_js	Include a JavaScript file.
express.ui.HTML	Mark a string as raw HTML. This will prevent the string from being escaped when rendered inside an HTML tag.
express.ui.tags	Functions for creating HTML tags.
express.ui.TagList	Create an HTML tag list (i.e., a fragment of HTML)
express.ui.busy_indicators.use	Enable/disable busy indication
express.ui.busy_indicators.options	Customize spinning busy indicators.

Application-level settings

express.app_opts

Set App-level options in Shiny Express

Express developer tooling

express.is_express_app	Detect whether an app file is a Shiny express app
express.wrap_express_app	Wrap a Shiny Express mode app into a Shiny `App` object.