Add support for xyzservices

[ahuang11]

Closes #517 and finishes holoviz/holoviews#5057

Based off https://github.com/holoviz/holoviews/pull/5062/files

import geoviews as gv
import xyzservices.providers as xyz
gv.extension("bokeh")

gv.WMTS(xyz.NASAGIBS.ViirsEarthAtNight2012)

[hoxbro]

Left some comments

[hoxbro]

I'm a little confused by this change. You are changing the WMTS class to contain WMTS, QUADKEY, and BBox.

[ahuang11]

Technically, it already supported all those; it just wasn't documented.

geoviews/geoviews/plotting/bokeh/__init__.py

Lines 52 to 56 in ec245c7

	tile_source = QUADKEYTileSource
	elif all(kw in element.data.upper() for kw in ('{XMIN}', '{XMAX}', '{YMIN}', '{YMAX}')):
	tile_source = BBoxTileSource
	elif all(kw in element.data.upper() for kw in ('{X}', '{Y}', '{Z}')):
	tile_source = WMTSTileSource

[ahuang11]

geoviews/geoviews/plotting/mpl/__init__.py

Lines 474 to 511 in ec245c7

	class WMTSPlot(GeoPlot):
	"""
	Adds a Web Map Tile Service from a WMTS Element.
	"""
	zoom = param.Integer(default=8, doc="""
	Controls the zoom level of the tile source.""")
	style_opts = ['alpha', 'cmap', 'interpolation', 'visible',
	'filterrad', 'clims', 'norm']
	def get_data(self, element, ranges, style):
	if isinstance(element.data, str):
	if '{Q}' in element.data:
	tile_source = QuadtreeTiles(url=element.data)
	else:
	tile_source = GoogleTiles(url=element.data)
	return (tile_source, self.zoom), style, {}
	else:
	tile_source = element.data
	return (tile_source, element.layer), style, {}
	def init_artists(self, ax, plot_args, plot_kwargs):
	if isinstance(plot_args[0], GoogleTiles):
	if 'artist' in self.handles:
	return {'artist': self.handles['artist']}
	img = ax.add_image(*plot_args, **plot_kwargs)
	return {'artist': img or plot_args[0]}
	return {'artist': ax.add_wmts(*plot_args, **plot_kwargs)}
	def teardown_handles(self):
	"""
	If no custom update_handles method is supplied this method
	is called to tear down any previous handles before replacing
	them.
	"""
	if not isinstance(self.handles.get('artist'), GoogleTiles):
	self.handles['artist'].remove()

[hoxbro]

Technically, it already supported all those; it just wasn't documented.

Isn't this something you added to this PR?

It just doesn't make sense to me to have a specific name for the class and then support more general cases.

[ahuang11]

No, this PR only adds support for XYZServices' classes (the package).

Yes, I understand that, but it'd be breaking change if we separated those out.

[ahuang11]

For example, this URL uses BBoxTileSource and all I'm using is gv.WMTS

radar_url_fmt = """
https://idpgis.ncep.noaa.gov/arcgis/services/radar/radar_base_reflectivity_time/ImageServer/WMSServer?
SERVICE=WMS
&VERSION=1.3.0
&REQUEST=GetMap
&FORMAT=image/png
&TRANSPARENT=true
&WIDTH=256
&HEIGHT=256
&CRS=EPSG:3857
&BBOX={XMIN},{YMIN},{XMAX},{YMAX}
&LAYERS=0
"""

to render it

https://ahuang11.github.io/web-map-feature-services-cookbook/notebooks/web_map_services.html#accessing-external-sources

Maybe we can deprecate gv.WMTS in favor of gv.Tiles

[hoxbro]

I think I got confused by the way Github highlighted stuff.

I think we should think about giving it a broader name for the class (but not in this PR).

[hoxbro]

Maybe we can deprecate gv.WMTS in favor of gv.Tiles

I think this would be a good idea. Let's do it in another PR.