@mattpap, thanks for adding this request to the 0.12.8 milestone.

BTW, as suggested in #6555, it would be great to be able to control the color of the progress bar. I mean the color, of the 'progression part' of the widget.

With recent changes to widgets and bringing them closer to bokehjs (removal of jquery-ui, partial removal of bootstrap), we will be able to implement a common styling API (definitively for 1.0, maybe sooner).

That's great. Thanks for sharing your roadmap.

This is definitely a good idea. We should keep in mind concurrent plans for busy and done events for long-running updates. Perhaps those could be endpoints of a more general progress-oriented set of properties.

Has any—ahem—progress been made on this?

I think this feature is not available now. though it is also what I want too.

There is no progress on this issue. If there was, it would be reflected here. Unfortunately, additions like this one are very low on core maintainers' priority list, so this is a perfect case for external contributors to help.

Just wanted to note that adding a basic progress bar will involve:

• Creating a python ProgressBar class. This will be a Model subclass that defines properties (e.g. percentage and bar_color maybe others) and probably does not have any actual "code"

• Creating a TypeScript implementation of that renders a progress bar in the DOM based on the properties of the model. The TypeScript class will subclass LayoutDOM. We can point to some analogous PR examples for whoever wants to work on this, and certainly answer questions / provide guidance all along the way.

Dear @bryevdv - I would like to work on this. I just looked into the code base and following are my understanding,

1. Create subclass PorgressBar in bokeh widgets
2. implement the actual TS code in bokehjs widgets.

I just looked into the existing PR request for this example and found this one as reference : #8464

Can you please tell me whether my understandings are correct and provide any guideline / inputs?

Thanks you,

We already have a ProgressBar model in Panel you can see here: https://panel.holoviz.org/reference/widgets/Progress.html

The implementation is here: https://github.com/holoviz/panel/blob/master/panel/models/progress.ts

We could definitely consider porting that to bokeh widgets.

That would be really nice! Is there any updates on this issue?

I have a couple questions about this issue:

1. A ProgressBar class does not seem like it would fit in with any of the files in bokeh/models/widgets (i.e. it would not fit in within button.py, sliders.py, or tables.py since it doesn't go in any of those categories), so would it be appropriate to make a new Python file like progress_bar.py? Or would that be too specific for this one widget?
2. @philippjfr You mentioned that there is already a TS ProgressBar model in Panel that could be ported over to bokeh widgets, would that entail copying that code over to bokeh? Or would there be a better way to make the model common to both projects?

I can recommend to have a look in the bokeh-garden "extension", it took me some time to figure out exactly how to use their progressbar on my bokeh site but here is a working example: emerald-geomodelling/BokehGarden#6 (comment)

@jadalilleboe From a user perspective everything is all under bokeh.models the module subdivisions are really just for the convenience of Bokeh developers. So it's not so important really. I might suggest a new bokeh.models.indicators module. In addition to a progress bar, that would be a good place for a "spinner" widget in the future as well.

The panel/holoviz implementation is here: https://github.com/holoviz/panel/blob/master/panel/models/progress.ts The only panel-specifc thing I see there is CachedVariadicBox which I don't really know much about. @philippjfr will have to comment on that, or if it makes sense to also port to Bokeh. It's possible that the upcoming layour work for Bokeh 3.0 will make CachedVariadicBox no longer relevant (cc @mattpap)

I am potentially in need of such widget as well.