I'm trying to create a dashboard with two holoviews objects: a panel pn.widgets.Select object that contains a list of xarray variables, and a hvplot object that takes the selected variable on input, like this:

def hvmesh(var=None):mesh = ds[var].hvplot.quadmesh(x='x', y='y', rasterize=True, crs=crs, width=600, height=400, groupby=list(ds[var].dims[:-2]), cmap='jet')return mesh

Here's what an example mesh looks like for a particular variable (one that has both time and height dimensions):

I would like to have the map update when I select a variable from the panel widget: I tried to do this as a dynamic map, like this:

from holoviews.streams import Params
import holoviews as hvvar_stream = Params(var_select, ['value'], rename={'value': 'var'})mesh = hv.DynamicMap(hvmesh, streams=[var_stream])

but when I try to display the map, I get:

Exception: Nesting a DynamicMap inside a DynamicMap is not supported.

It would seem a common need to select the variable for hvplot from a panel widget. What is the best way to accomplish this with pyviz?

In case it's useful, here is my full attempt Jupyter Notebook.

Because the groupby changes with each variable selected, a list of variables can not be passed to hvplot. So one solution is to just recreate the plot each time a new variable is selected. This works:

import holoviews as hv
from holoviews.streams import Paramsdef plot(var=None, tiles=None):var = var or var_select.valuetiles = tiles or map_select.valuemesh = ds[var].hvplot.quadmesh(x='x', y='y', rasterize=True, crs=crs, title=var,width=600, height=400, groupby=list(ds[var].dims[:-2]), cmap='jet')return mesh.opts(alpha=0.7) * tilesdef on_var_select(event):var = event.obj.valuecol[-1] = plot(var=var)def on_map_select(event):tiles = event.obj.valuecol[-1] = plot(tiles=tiles)var_select.param.watch(on_var_select, parameter_names=['value']);
map_select.param.watch(on_map_select, parameter_names=['value']);col = pn.Column(var_select, map_select, plot(var_select.value) * tiles)

producing:

Here is the full notebook.