Unified WMTS element support across backends (#120)

geoviews/element/geo.py

@@ -2,7 +2,7 @@
 import numpy as np
 from cartopy import crs as ccrs
 from cartopy.feature import Feature as cFeature
-from cartopy.io.img_tiles import GoogleTiles as cGoogleTiles
+from cartopy.io.img_tiles import GoogleTiles
 from cartopy.io.shapereader import Reader
 from holoviews.core import Element2D, Dimension, Dataset as HvDataset, NdOverlay
 from holoviews.core.util import basestring, pd, max_extents, dimension_range
@@ -29,7 +29,7 @@
 
 from ..util import path_to_geom, polygon_to_geom
 
-geographic_types = (cGoogleTiles, cFeature, BaseGeometry)
+geographic_types = (GoogleTiles, cFeature, BaseGeometry)
 
 def is_geographic(element, kdims=None):
     """
@@ -78,7 +78,7 @@ def __init__(self, data, kdims=None, vdims=None, **kwargs):
             coord_sys = crs_data.coord_system()
             if hasattr(coord_sys, 'as_cartopy_projection'):
                 crs = coord_sys.as_cartopy_projection()
-        elif isinstance(crs_data, (cFeature, cGoogleTiles)):
+        elif isinstance(crs_data, (cFeature, GoogleTiles)):
             crs = crs_data.crs
 
         supplied_crs = kwargs.get('crs', None)
@@ -138,51 +138,36 @@ def range(self, dim, data_range=True):
 
 class WMTS(_GeoFeature):
     """
-    The WMTS Element represents a Web Map Tile Service
-    specified as a tuple of the API URL and
+    The WMTS Element represents a Web Map Tile Service specified as a
+    URL containing {x}, {y}, and {z} templating variables, e.g.:
+
+    https://maps.wikimedia.org/osm-intl/{Z}/{X}/{Y}@2x.png
     """
 
     group = param.String(default='WMTS')
 
     layer = param.String(doc="The layer on the tile service")
 
     def __init__(self, data, kdims=None, vdims=None, **params):
-        if isinstance(data, tuple):
-            data = data
-        else:
-            data = (data,)
-
-        for d in data:
-            if WMTSTileSource and isinstance(d, WMTSTileSource):
-                if not 'crs' in params:
-                    params['crs'] = ccrs.GOOGLE_MERCATOR
-            elif WebMapTileService and isinstance(d, WebMapTileService):
-                if 'crs' not in params and not self.crs:
-                    raise Exception('Must supply coordinate reference '
-                                    'system with cartopy WMTS URL.')
-            elif not isinstance(d, basestring):
-                raise TypeError('%s data has to be a tile service URL'
-                                % type(d).__name__)
-            elif not 'crs' in params:
-                params['crs'] = ccrs.GOOGLE_MERCATOR
+        if ((WMTSTileSource and isinstance(data, WMTSTileSource)) or
+            (GoogleTiles and isinstance(data, GoogleTiles))):
+            data = data.url
+        elif WebMapTileService and isinstance(data, WebMapTileService):
+            pass
+        elif not isinstance(data, basestring):
+            raise TypeError('%s data should be a tile service URL not a %s type.'
+                            % (type(self).__name__, type(data).__name__) )
         super(WMTS, self).__init__(data, kdims=kdims, vdims=vdims, **params)
 
 
-class Tiles(_GeoFeature):
+class Tiles(WMTS):
     """
     Tiles represents an image tile source to dynamically
     load data from depending on the zoom level.
     """
 
     group = param.String(default='Tiles')
 
-    def __init__(self, data, kdims=None, vdims=None, **params):
-        if not isinstance(data, cGoogleTiles):
-            raise TypeError('%s data has to be a cartopy GoogleTiles type'
-                            % type(data).__name__)
-        super(Tiles, self).__init__(data, kdims=kdims, vdims=vdims, **params)
-
-
 
 class Dataset(_Element, HvDataset):
     """

geoviews/plotting/bokeh/__init__.py

@@ -34,22 +34,10 @@ def get_extents(self, element, ranges):
         return extents
 
     def get_data(self, element, ranges, style):
-        tile_source = None
-        for url in element.data:
-            if isinstance(url, util.basestring) and not url.endswith('cgi'):
-                try:
-                    tile_source = WMTSTileSource(url=url)
-                    break
-                except:
-                    pass
-            elif isinstance(url, WMTSTileSource):
-                tile_source = url
-                break
-
-        if tile_source is None:
-            raise SkipRendering("No valid tile source URL found in WMTS "
-                                "Element, rendering skipped.")
-        return {}, {'tile_source': tile_source}, style
+        if not isinstance(element.data, util.basestring):
+            SkipRendering("WMTS element data must be a URL string, "
+                          "bokeh cannot render %r" % element.data)
+        return {}, {'tile_source': WMTSTileSource(url=element.data)}, style
 
     def _update_glyph(self, renderer, properties, mapping, glyph):
         allowed_properties = glyph.properties()

geoviews/plotting/mpl/__init__.py

@@ -3,6 +3,7 @@
 import numpy as np
 import param
 from cartopy import crs as ccrs
+from cartopy.io.img_tiles import GoogleTiles
 
 try:
     from owslib.wmts import WebMapTileService
@@ -385,50 +386,25 @@ class WMTSPlot(GeoPlot):
     Adds a Web Map Tile Service from a WMTS Element.
     """
 
-    style_opts = ['alpha', 'cmap', 'interpolation', 'visible',
-                  'filterrad', 'clims', 'norm']
-
-    def get_data(self, element, ranges, style):
-        if WebMapTileService is None:
-            raise SkipRendering('WMTS element requires owslib and PIL '
-                                'to be installed.')
-        tile_source = None
-        for url in element.data:
-            if isinstance(url, util.basestring):
-                try:
-                    tile_source = WebMapTileService(url)
-                    break
-                except:
-                    pass
-            elif isinstance(url, WebMapTileService):
-                tile_source = url
-                break
-
-        if tile_source is None:
-            raise SkipRendering("No valid tile source URL found in WMTS "
-                                "Element, rendering skipped.")
-        return (tile_source, element.layer), style, {}
-
-    def init_artists(self, ax, plot_args, plot_kwargs):
-        return {'artist': ax.add_wmts(*plot_args, **plot_kwargs)}
-
-
-class TilePlot(GeoPlot):
-    """
-    Draws image tiles specified by a Tiles 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):
-        return (element.data, self.zoom), style, {}
+        if isinstance(element.data, util.basestring):
+            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):
-        return {'artist': ax.add_image(*plot_args, **plot_kwargs)}
+        if isinstance(plot_args[0], GoogleTiles):
+            return {'artist': ax.add_image(*plot_args, **plot_kwargs)}
+        return {'artist': ax.add_wmts(*plot_args, **plot_kwargs)}
+
 
 
 class GeoAnnotationPlot(AnnotationPlot):
@@ -480,7 +456,7 @@ def draw_annotation(self, axis, data, crs, opts):
                 Image: GeoImagePlot,
                 Feature: FeaturePlot,
                 WMTS: WMTSPlot,
-                Tiles: TilePlot,
+                Tiles: WMTSPlot,
                 Points: GeoPointPlot,
                 Text: GeoTextPlot,
                 Layout: LayoutPlot,