App

App(self, ui, server, *, static_assets=None, debug=False)

Create a Shiny app instance.

Parameters

ui : Tag | TagList | Callable[[Request], Tag | TagList] | Path

The UI definition for the app (e.g., a call to page_fluid or similar, with layouts and controls nested inside). You can also pass a function that takes a Request and returns a UI definition, if you need the UI definition to be created dynamically for each pageview.

server : Callable[[Inputs], None] | Callable[[Inputs, Outputs, Session], None] | None

A function which is called once for each session, ensuring that each session is independent.

static_assets : Optional[str | Path | Mapping[str, str | Path]] = None

Static files to be served by the app. If this is a string or Path object, it must be a directory, and it will be mounted at /. If this is a dictionary, each key is a mount point and each value is a file or directory to be served at that mount point.

debug : bool = False

Whether to enable debug mode.

Examples

from shiny import  App, Inputs, Outputs, Session, ui

app_ui = ui.page_fluid("Hello Shiny!")

def server(input: Inputs, output: Outputs, session: Session):
    pass

app = App(app_ui, server)

Attributes

Name	Description
lib_prefix	str(object=’’) -> str str(bytes_or_buffer[, encoding[, errors]]) -> str
sanitize_error_msg	str(object=’’) -> str str(bytes_or_buffer[, encoding[, errors]]) -> str
sanitize_errors	bool(x) -> bool

Methods

Name	Description
call_pyodide	Communicate with pyodide.
on_shutdown	Register a callback to be called when the app is shutting down. This can be useful for cleaning up app-wide resources, like connection pools, temporary directories, worker threads/processes, etc.
run	Run the app.
stop	Stop the app (i.e., close all sessions).

call_pyodide

App.call_pyodide(scope, receive, send)

Communicate with pyodide.

Warning

This method is not intended for public usage. It’s exported for use by shinylive.

on_shutdown

App.on_shutdown(callback)

Register a callback to be called when the app is shutting down. This can be useful for cleaning up app-wide resources, like connection pools, temporary directories, worker threads/processes, etc.

Parameters

callback : Callable[[], None]

The callback to call. It should take no arguments, and any return value will be ignored. Try not to raise an exception in the callback, as exceptions during cleanup can hide the original exception that caused the app to shut down.

Returns

: Callable[[], None]

The callback, to allow this method to be used as a decorator.

run

App.run(**kwargs)

Run the app.

Parameters

****kwargs** : object = {}

Keyword arguments passed to run_app.

stop

App.stop()

Stop the app (i.e., close all sessions).

See Also

• close