Add max zoom default

examples/user_guide/Working_with_Bokeh.ipynb

@@ -72,7 +72,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "gts.EsriImagery.opts(width=600, height=570, global_extent=True) * gts.StamenLabels.options(level='annotation')"
+    "gts.EsriImagery.opts(width=600, height=570, global_extent=True) * gts.StamenLabels.opts(level='annotation')"
    ]
   },
   {
@@ -95,6 +95,22 @@
     "gv.util.get_tile_rgb(tiles, bbox=(-180, -70, 180, 70), zoom_level=1).opts(width=500, height=500, projection=ccrs.Orthographic())"
    ]
   },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "Note, that a `max_zoom` default is set for some tile sources; if you need a more detailed map, and the tile source supports it, you can increase this value. However, if the tile source does not support the requested zoom level, the tile source could return tiles that are empty or tiles that note \"map data not yet available\", depending on how the tile source handles those requests."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "gts.EsriImagery.opts(max_zoom=30)"
+   ]
+  },
   {
    "cell_type": "markdown",
    "metadata": {},

geoviews/plotting/bokeh/__init__.py

@@ -49,7 +49,14 @@
     project_quadmesh,
     project_vectorfield,
 )
-from ...tile_sources import _ATTRIBUTIONS
+from ...tile_sources import (
+    _ATTRIBUTIONS,
+    ESRI,
+    OSM,
+    EsriImagery,
+    EsriNatGeo,
+    EsriWorldHillshade,
+)
 from ...util import line_types, poly_types
 from . import callbacks  # noqa
 from .plot import GeoOverlayPlot, GeoPlot
@@ -60,6 +67,15 @@
     class ImageStackPlot:
         ...
 
+_TILE_MAX_ZOOM = {
+    OSM: 19,
+    ESRI: 19,
+    EsriImagery: 19,
+    EsriNatGeo: 16,
+    EsriWorldHillshade: 16,
+}
+
+
 class TilePlot(GeoPlot):
 
     style_opts = [
@@ -102,6 +118,8 @@ def get_data(self, element, ranges, style):
                                 'Must contain {X}/{Y}/{Z}, {XMIN}/{XMAX}/{YMIN}/{YMAX} '
                                 'or {Q} template strings.')
             params = {'url': element.data}
+            if element in _TILE_MAX_ZOOM:
+                params['max_zoom'] = _TILE_MAX_ZOOM[element]
             for zoom in ('min_zoom', 'max_zoom'):
                 if zoom in style:
                     params[zoom] = style[zoom]

geoviews/tests/plotting/bokeh/test_tiles.py

@@ -3,6 +3,8 @@
 from holoviews.tests.plotting.bokeh.test_plot import TestBokehPlot, bokeh_renderer
 
 from geoviews.element import WMTS
+from geoviews.plotting.bokeh import TilePlot
+from geoviews.tile_sources import OSM
 
 
 class TestWMTSPlot(TestBokehPlot):
@@ -17,3 +19,7 @@ def test_xyzservices_tileprovider(self):
         assert glyph.attribution == osm.html_attribution
         assert glyph.url == osm.build_url(scale_factor="@2x")
         assert glyph.max_zoom == osm.max_zoom
+
+    def test_max_zoom_default(self):
+        tile_source = TilePlot(OSM).get_data(OSM, (0, 0, 0, 0), {})[1]["tile_source"]
+        assert tile_source.max_zoom == 19