Fixed WMTS update with url

[philippjfr]

In previous PRs we allowed creating a WMTS element with just a URL, however the plotting code then ended up trying to replace the original tile source object. This fixes this issue.

[jbednar]

Looks good to me apart from the failing test.

[philippjfr]

Now fixed.

[jlstevens]

Merging given the tests have passed and Jim approved this PR.

[digitaltopo]

While following @jbednar's LandSat example I'm getting the error:

ValueError: not enough values to unpack (expected 3, got 2)

when calling tiles in the cell where we render blue band as black and white with Stamen basemap:

%opts RGB [width=600 height=600]
tiles = gv.WMTS(STAMEN_TONER)
tiles * shade(regrid(hv.Image(bands[1])), cmap=['black', 'white']).redim(x='Longitude', y='Latitude')

(same happens with just tiles by itself, without the shaded, regridded hv.Image)

Is this related?

Looking at source for geoviews.WMTS the docs seem to be cut off:

 The WMTS Element represents a Web Map Tile Service specified as a tuple of the API URL and

Can't get past this part in the example for now.

Here's the full error:

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.applications/anaconda3/envs/my-env/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.applications/anaconda3/envs/my-env/lib/python3.6/site-packages/holoviews/ipython/display_hooks.py in pprint_display(obj)
    257     if not ip.display_formatter.formatters['text/plain'].pprint:
    258         return None
--> 259     return display(obj, raw=True)
    260 
    261 

~/.applications/anaconda3/envs/my-env/lib/python3.6/site-packages/holoviews/ipython/display_hooks.py in display(obj, raw, **kwargs)
    237     elif isinstance(obj, (CompositeOverlay, ViewableElement)):
    238         with option_state(obj):
--> 239             html = element_display(obj)
    240     elif isinstance(obj, (Layout, NdLayout, AdjointLayout)):
    241         with option_state(obj):

~/.applications/anaconda3/envs/my-env/lib/python3.6/site-packages/holoviews/ipython/display_hooks.py in wrapped(element)
    130         try:
    131             html = fn(element,
--> 132                       max_frames=OutputSettings.options['max_frames'])
    133 
    134             # Only want to add to the archive for one display hook...

~/.applications/anaconda3/envs/my-env/lib/python3.6/site-packages/holoviews/ipython/display_hooks.py in element_display(element, max_frames)
    176     if renderer.fig == 'pdf':
    177         renderer = renderer.instance(fig='png')
--> 178     return renderer.html(element, fmt=renderer.fig)
    179 
    180 

~/.applications/anaconda3/envs/my-env/lib/python3.6/site-packages/holoviews/plotting/renderer.py in html(self, obj, fmt, css, comm, **kwargs)
    256         code to initialize a Comm, if the plot supplies one.
    257         """
--> 258         plot, fmt =  self._validate(obj, fmt)
    259         figdata, _ = self(plot, fmt, **kwargs)
    260         if css is None: css = self.css

~/.applications/anaconda3/envs/my-env/lib/python3.6/site-packages/holoviews/plotting/renderer.py in _validate(self, obj, fmt)
    192         if isinstance(obj, tuple(self.widgets.values())):
    193             return obj, 'html'
--> 194         plot = self.get_plot(obj, renderer=self)
    195 
    196         fig_formats = self.mode_formats['fig'][self.mode]

~/.applications/anaconda3/envs/my-env/lib/python3.6/site-packages/holoviews/plotting/bokeh/renderer.py in get_plot(self_or_cls, obj, doc, renderer)
    115         combining the bokeh model with another plot.
    116         """
--> 117         plot = super(BokehRenderer, self_or_cls).get_plot(obj, renderer)
    118         if self_or_cls.mode == 'server' and doc is None:
    119             doc = curdoc()

~/.applications/anaconda3/envs/my-env/lib/python3.6/site-packages/holoviews/plotting/renderer.py in get_plot(self_or_cls, obj, renderer)
    179             plot = self_or_cls.plotting_class(obj)(obj, renderer=renderer,
    180                                                    **plot_opts)
--> 181             plot.update(0)
    182         else:
    183             plot = obj

~/.applications/anaconda3/envs/my-env/lib/python3.6/site-packages/holoviews/plotting/plot.py in update(self, key)
    483     def update(self, key):
    484         if len(self) == 1 and key == 0 and not self.drawn:
--> 485             return self.initialize_plot()
    486         item = self.__getitem__(key)
    487         self.traverse(lambda x: setattr(x, '_updated', True))

~/.applications/anaconda3/envs/my-env/lib/python3.6/site-packages/holoviews/plotting/bokeh/element.py in initialize_plot(self, ranges, plot, plots, source)
    781         self.handles['plot'] = plot
    782 
--> 783         self._init_glyphs(plot, element, ranges, source)
    784         if not self.overlaid:
    785             self._update_plot(key, plot, style_element)

~/.applications/anaconda3/envs/my-env/lib/python3.6/site-packages/holoviews/plotting/bokeh/element.py in _init_glyphs(self, plot, element, ranges, source)
    732         else:
    733             style = self.style[self.cyclic_index]
--> 734             data, mapping, style = self.get_data(element, ranges, style)
    735             current_id = element._plot_id
    736         if source is None:

ValueError: not enough values to unpack (expected 3, got 2)

holoviews:  1.9.0
heoviews: 1.3.2
bokeh: 0.12.10
python: 3.6 on anaconda3 

Thanks for your help!

[philippjfr]

@digitaltopo Please upgrade to geoviews 1.4.0 with conda install -c holoviews geoviews

[digitaltopo]

Thanks for your reply! Upgrading took care of the issue!
I wasn't seeing the 1.4.0 release through conda but instead upgraded using pip from the git tag:

pip install git+https://github.com/ioam/geoviews.git@1.4.0 --upgrade