ui.show_offcanvas

ui.show_offcanvas(offcanvas, *, session=None)

Show an offcanvas panel.

Programmatically displays an offcanvas panel in the user's session. offcanvas can be:

• a string id of an offcanvas panel already in the UI, which is revealed; or
• arbitrary tag content (e.g. an HTML string, a Tag, or a TagList), which is wrapped into a new anonymous offcanvas panel with default settings; or
• an Offcanvas object created by offcanvas, which is rendered into the page (if needed) and shown.

Parameters

offcanvas : Union[str, TagChild, Offcanvas]

The panel’s id, tag content for a new panel, or an Offcanvas object.

session : Optional[Session] = None

The Session to show the panel in. If not provided, the session is inferred via get_current_session.

Returns

: str

The local (pre-namespace) ID of the displayed panel.

Note

If a panel with the same id is already present on the page, show_offcanvas() simply reveals it — the content is not re-rendered. To update an id’d panel’s content, update the reactive outputs it contains rather than calling show_offcanvas() again.

A plain string is always treated as an id lookup, and raises a ValueError if it looks like body text instead (it is empty or contains whitespace). To show new string content, wrap it in HTML or pass a offcanvas object.

See Also

• offcanvas
• hide_offcanvas
• toggle_offcanvas

Examples

#| '!! shinylive warning !!': |
#|   shinylive does not work in self-contained HTML documents.
#|   Please set `embed-resources: false` in your metadata.
#| standalone: true
#| components: [editor, viewer]
#| layout: vertical
#| viewerHeight: 400

## file: app.py
from shiny import App, Inputs, Outputs, Session, reactive, ui

app_ui = ui.page_fluid(
    ui.offcanvas(
        ui.p("This panel is declared in the UI."),
        title="Existing panel",
        id="existing_panel",
    ),
    ui.input_action_button("show_existing_btn", "Show existing panel"),
    ui.input_action_button("show_server_btn", "Show server panel"),
    ui.input_action_button("show_markdown_btn", "Show markdown content"),
)


def server(input: Inputs, output: Outputs, session: Session):
    @reactive.effect
    @reactive.event(input.show_existing_btn)
    def _():
        # Reveal a panel already declared in the UI, by its id.
        ui.show_offcanvas("existing_panel")

    @reactive.effect
    @reactive.event(input.show_server_btn)
    def _():
        # Build and show a new, anonymous panel entirely from the server.
        ui.show_offcanvas(
            ui.offcanvas(
                ui.p("This panel was inserted dynamically by the server."),
                title="Server Panel",
                placement="left",
            )
        )

    @reactive.effect
    @reactive.event(input.show_markdown_btn)
    def _():
        # Bare tag content (here, rendered Markdown) is wrapped into a new
        # anonymous panel with default settings.
        ui.show_offcanvas(ui.markdown("""
                ### Markdown content

                This panel's body was written in **Markdown** and wrapped
                into a new anonymous offcanvas by `show_offcanvas()`.
                """))


app = App(app_ui, server=server)