Panel Code Issue

Panel
, ,
1

Hello Community!

I was trying several ways to serve multiple applications and I found the following as one of the ways:

import panel as pn

pn.extension(sizing_mode="stretch_width")

pages = {
    "Page 1": pn.Column("# Page 1", "...bla bla bla"),
    "Page 2": pn.Column("# Page 2", "...more bla"),
}


def show(page):
    return pages[page]


starting_page = pn.state.session_args.get("page", [b"Page 1"])[0].decode()
page = pn.widgets.RadioButtonGroup(
    value=starting_page,
    options=list(pages.keys()),
    name="Page",
    sizing_mode="fixed",
    button_type="success",
)
ishow = pn.bind(show, page=page)
pn.state.location.sync(page, {"value": "page"})

ACCENT_COLOR = "#0072B5"
DEFAULT_PARAMS = {
    "site": "Panel Multi Page App",
    "accent_base_color": ACCENT_COLOR,
    "header_background": ACCENT_COLOR,
}
pn.template.FastListTemplate(
    title="As Single Page App",
    sidebar=[page],
    main=[ishow],
    **DEFAULT_PARAMS,
).servable()

However, when I run this code on my device, this error pops up:

    pn.state.location.sync(page, {"value": "page"})

AttributeError: 'NoneType' object has no attribute 'sync'

Can anyone help how to resolve this?

Thanks!

2

From Access and Manipulate the URL — Panel v1.5.4

In a notebook environment pn.state.location is not initialized until the first plot has been displayed

Are you using a notebook?