The properties of a basemap do not change when the basemap does.

[algol60]

Software Version Info

gv.__version__='1.15.0'
hv.__version__='1.20.2'
bokeh.__version__='3.8.1'

Description of expected behavior and the observed behavior

When using a HoloViews stream to change the basemap:

• When the basemap changes, the displayed attribution does not change.
• If the WMTS URL changes from WMTSTileSource style ({z} {x} {y}) to BBoxTileSource style ({XMIN},{YMIN},{XMAX},{YMAX}), or vice versa, the placeholders are not replaced with values. This can be seen in the browser's developer tools. This means that the tile server is being sent bad tile URLs.

Complete, minimal, self-contained example code that reproduces the issue

import holoviews as hv
import geoviews as gv
from geoviews.element import WMTS
import bokeh

hv.extension('bokeh', inline=True)
gv.extension('bokeh', inline=True)
print(f'{gv.__version__=}\n{hv.__version__=}\n{bokeh.__version__=}') 

xy1 = gv.tile_sources.OSM
xy2 = gv.tile_sources.EsriImagery
mm1 = WMTS('https://server.arcgisonline.com/arcgis/rest/services/World_Imagery/MapServer/export?bbox={XMIN},{YMIN},{XMAX},{YMAX}&size=512,512&imageSR=&format=png&transparent=false&f=image')

# Start with a WMTSTileSource.
BmStream = hv.streams.Stream.define('basemap_stream', bm=xy1)
bm_stream = BmStream()

def callback(bm):
    return bm
    
dynmap = hv.DynamicMap(callback, streams=[bm_stream])
# Display the map in a notebook cell.
dynmap

# New notebook cell.
# Change basemap, but the displayed attribution does not change.
dynmap.event(bm=xy2)

# New notebook cell.
# Change to a BBoxTileSource, the URL containing the placeholders {XMIN} etc is used.
# See the browser's developer tools network tab.
dynmap.event(bm=mm1)

[hoxbro]

Both items look like bugs to me.