Tile source replacement warnings (#4941)

Author: jlstevens

CHANGELOG.md

@@ -1,9 +1,9 @@
 Version 1.14.4
 ==============
 
-This release primarily focuses on a number of bug fixes. Many thanks
-to @Hoxbro, @nitrocalcite, @brl0, @hyamanieu, @rafiyr, @jbednar and
-@philippjfr for contributing.
+This release primarily focuses on a number of bug fixes. Many thanks to
+@Hoxbro, @nitrocalcite, @brl0, @hyamanieu, @rafiyr, @jbednar, @jlstevens
+and @philippjfr for contributing.
 
 Enhancements:
 
@@ -40,6 +40,20 @@ Documentation:
 - Updated docs to correctly declare Scatter kdims
   ([#4914](https://github.com/holoviz/holoviews/pull/4914))
 
+Compatibility:
+
+Unfortunately a number of tile sources are no longer publicly
+available. Attempting to use these tile sources will now issue warnings
+unless `hv.config.raise_deprecated_tilesource_exception` is set to
+`True` in which case exceptions will be raised instead.
+
+- The `Wikipedia` tile source is no longer available as it is no longer
+  being served outside the wikimedia domain. As one of the most
+  frequently used tile sources, HoloViews now issues a warning and
+  switches to the OpenStreetMap (OSM) tile source instead.
+- The `CartoMidnight` and `CartoEco` tile sources are no longer publicly
+  available. Attempting to use these tile sources will result in a
+  deprecation warning.
 
 Version 1.14.3
 ==============

doc/releases.rst

@@ -7,9 +7,9 @@ Version 1.14
 Version 1.14.4
 **************
 
-This release primarily focuses on a number of bug fixes. Many thanks
-to @Hoxbro, @nitrocalcite, @brl0, @hyamanieu, @rafiyr, @jbednar and
-@philippjfr for contributing.
+This release primarily focuses on a number of bug fixes. Many thanks to
+@Hoxbro, @nitrocalcite, @brl0, @hyamanieu, @rafiyr, @jbednar, @jlstevens
+and @philippjfr for contributing.
 
 Enhancements:
 
@@ -46,6 +46,21 @@ Documentation:
 - Updated docs to correctly declare Scatter kdims
   (`#4914 <https://github.com/holoviz/holoviews/pull/4914>`_)
 
+Compatibility:
+
+Unfortunately a number of tile sources are no longer publicly available.
+Attempting to use these tile sources will now issue warnings unless
+``hv.config.raise_deprecated_tilesource_exception`` is set to ``True``
+in which case exceptions will be raised instead.
+
+-  The ``Wikipedia`` tile source is no longer available as it is no
+   longer being served outside the wikimedia domain. As one of the most
+   frequently used tile sources, HoloViews now issues a warning and
+   switches to the OpenStreetMap (OSM) tile source instead.
+-  The ``CartoMidnight`` and ``CartoEco`` tile sources are no longer
+   publicly available. Attempting to use these tile sources will result
+   in a deprecation warning.
+
 
 Version 1.14.3
 **************

holoviews/core/util.py

@@ -163,6 +163,10 @@ class Config(param.ParameterizedFunction):
        Global default colormap for HeatMap elements. Prior to HoloViews
        1.14.0, the default value was the 'RdYlBu_r' colormap.""")
 
+    raise_deprecated_tilesource_exception = param.Boolean(default=False,
+       doc=""" Whether deprecated tile sources should raise a
+       deprecation exception instead of issuing warnings.""")
+
     def __call__(self, **params):
         self.param.set_param(**params)
         return self

holoviews/element/tiles.py

@@ -131,11 +131,25 @@ def easting_northing_to_lon_lat(easting, northing):
     )
 }
 
+def deprecation_warning(name, url, reason):
+    def deprecated_tilesource_warning():
+        if util.config.raise_deprecated_tilesource_exception:
+            raise DeprecationWarning('%s tile source is deprecated: %s' % (name, reason))
+        param.main.param.warning('%s tile source is deprecated and is likely to be unusable: %s' %  (name, reason))
+        return Tiles(url, name=name)
+    return deprecated_tilesource_warning
+
+
 # CartoDB basemaps
 CartoDark = lambda: Tiles('https://cartodb-basemaps-4.global.ssl.fastly.net/dark_all/{Z}/{X}/{Y}.png', name="CartoDark")
-CartoEco = lambda: Tiles('https://3.api.cartocdn.com/base-eco/{Z}/{X}/{Y}.png', name="CartoEco")
 CartoLight = lambda: Tiles('https://cartodb-basemaps-4.global.ssl.fastly.net/light_all/{Z}/{X}/{Y}.png', name="CartoLight")
-CartoMidnight = lambda: Tiles('https://3.api.cartocdn.com/base-midnight/{Z}/{X}/{Y}.png', name="CartoMidnight")
+CartoMidnight = deprecation_warning('CartoMidnight',
+                                    'https://3.api.cartocdn.com/base-midnight/{Z}/{X}/{Y}.png',
+                                    'no longer publicly available.')
+CartoEco = deprecation_warning('CartoEco',
+                               'https://3.api.cartocdn.com/base-eco/{Z}/{X}/{Y}.png',
+                               'no longer publicly available.')
+
 
 # Stamen basemaps
 StamenTerrain = lambda: Tiles('https://stamen-tiles.a.ssl.fastly.net/terrain/{Z}/{X}/{Y}.png', name="StamenTerrain")
@@ -157,8 +171,23 @@ def easting_northing_to_lon_lat(easting, northing):
 EsriReference = lambda: Tiles('https://server.arcgisonline.com/ArcGIS/rest/services/Reference/World_Reference_Overlay/MapServer/tile/{Z}/{Y}/{X}', name="EsriReference")
 ESRI = EsriImagery # For backwards compatibility with gv 1.5
 
+
+def wikimedia_replacement():
+    if util.config.raise_deprecated_tilesource_exception:
+        raise DeprecationWarning('Wikipedia tile source no longer available outside '
+                                 'wikimedia domain as of April 2021.')
+
+    param.main.param.warning('Wikipedia tile source no longer available outside '
+                             'wikimedia domain as of April 2021; switching '
+                             'to OpenStreetMap (OSM) tile source. '
+                             'See release notes for HoloViews'
+                             ' 1.14.4 for more details')
+    return Tiles('https://c.tile.openstreetmap.org/{Z}/{X}/{Y}.png', name="OSM")
+
 # Miscellaneous
 OSM = lambda: Tiles('https://c.tile.openstreetmap.org/{Z}/{X}/{Y}.png', name="OSM")
-Wikipedia = lambda: Tiles('https://maps.wikimedia.org/osm-intl/{Z}/{X}/{Y}@2x.png', name="Wikipedia")
+Wikipedia = wikimedia_replacement
 
-tile_sources = {k: v for k, v in locals().items() if isinstance(v, FunctionType) and k not in ['ESRI', 'lon_lat_to_easting_northing', 'easting_northing_to_lon_lat']}
+tile_sources = {k: v for k, v in locals().items() if isinstance(v, FunctionType) and k not in
+                ['ESRI', 'lon_lat_to_easting_northing', 'easting_northing_to_lon_lat',
+                 'deprecation_warning', 'wikimedia_replacement']}