Autoreload opens new tab when launching a server dynamically (pn.serve())

[gforti84]

Software versions: Panel = 1.3.8 bokeh = 3.3.4 python = 3.11.7 OS = Linux Mint 21.2 browser = Firefox 122.0.1

When serving the app dynamically, I've tried to use autoreload = True. It worked in the sense that every code update auto reloads the app. However, it opens a new tab. When using the command to serve my app, this does not happen.

I am using:

pn.serve(panel_app, title="Who am I?", port = 9001, websocket_origin=['*'], autoreload = True, show = True)

[philippjfr]

This isn't really that surprising now that I think about it and I'm not sure practically what can be done about it. What autoreload does is watch the script and re-execute it if it has changed, but if the script runs pn.serve then re-executing it will once again start a server.

[philippjfr]

May have to close this as wontfix unfortunately as it is quite unclear how autoreload should even work in this context. The only reasonable thing that might be supported is:

pn.serve(path_to_app, title="Who am I?", port = 9001, websocket_origin=['*'], autoreload = True, show = True)

[gforti84]

What do you mean by 'path_to_app'?

[MarcSkovMadsen]

path_to_app is what you want to serve. For example a function returning a Panel component. I believe (?) it can also be a path to a file. That is why its called path_to_app.

[kdheepak]

What do you recommend users should do if they have files like this:

./my_python_package/app.py:

from . import other_module

class App(pn.viewable.Viewer):
    def __panel__(self):
        return ...

./my_python_package/cli.py:

@click.command
def dashboard():
    from . import app
    pn.serve(app.App(), autoreload=True, show=True)

if __name__ == "__main__":
    cli()

The reason I want to structure my project like this is that I can then use the following in a notebook to demo to users:

from my_python_project import app
app.App()

and ship a command line interface for users like

$ my_project_project dashboard

My use case is that I have a complex application that already uses pyproject.toml to manage dependencies and I want to introduce panel incrementally. I would also like to import the components into a notebook to develop them or demo them. I would also like to panel serve my_python_project:app::App --autoreload --show to develop in non-jupyter environments. And I would like this to be user friendly for the rest of the team as well as I introduce panel to the team.

I understand that panel serve filename.py --autoreload --show works. I can make a separate folder outside the python project called ./scripts/app.py with the following content:

from my_python_project import app
app.App().servable()

However that is rather clunky and would like to not do that because I expect I'll have multiple dashboards / components.

Is there a workaround for this?

[hoxbro]

You could use pn.state.served:

if pn.state.served:
    app.App().servable()

[kdheepak]

Sorry, can you clarify? Where would I put those lines?

[hoxbro]

Files where you want to serve the app, something like this:

if __name__ == "__main__":
    cli()
elif pn.state.served:
    from . import app
    app.App().servable()