Suppress bokeh warnings

holoviews/plotting/bokeh/renderer.py

@@ -12,6 +12,7 @@
 from param.parameterized import bothmethod
 from bokeh.application.handlers import FunctionHandler
 from bokeh.application import Application
+from bokeh.core.validation.warnings import EMPTY_LAYOUT, MISSING_RENDERERS
 from bokeh.document import Document
 from bokeh.embed.notebook import encode_utf8, notebook_content
 from bokeh.io import curdoc, show as bkshow
@@ -26,7 +27,7 @@
 from ..plot import Plot, GenericElementPlot
 from ..renderer import Renderer, MIME_TYPES, HTML_TAGS
 from .widgets import BokehScrubberWidget, BokehSelectionWidget, BokehServerWidgets
-from .util import attach_periodic, compute_plot_size, bokeh_version
+from .util import attach_periodic, compute_plot_size, bokeh_version, silence_warnings
 
 NOTEBOOK_DIV = """
 {plot_div}
@@ -286,7 +287,8 @@ def _figure_data(self, plot, fmt='html', doc=None, as_script=False, **kwargs):
                 js = ''
         else:
             try:
-                js, div, _ = notebook_content(model)
+                with silence_warnings(EMPTY_LAYOUT, MISSING_RENDERERS):
+                    js, div, _ = notebook_content(model)
                 html = NOTEBOOK_DIV.format(plot_script=js, plot_div=div)
                 data = encode_utf8(html)
                 doc.hold()

holoviews/plotting/bokeh/util.py

@@ -15,6 +15,7 @@
 
 from bokeh.core.json_encoder import serialize_json # noqa (API import)
 from bokeh.core.properties import value
+from bokeh.core.validation import silence
 from bokeh.layouts import WidgetBox, Row, Column
 from bokeh.models import tools
 from bokeh.models import Model, ToolbarBox, FactorRange, Range1d, Plot, Spacer, CustomJS, GridBox
@@ -333,6 +334,20 @@ def compute_layout_properties(
              'plot_width'  : width})
 
 
+@contextmanager
+def silence_warnings(*warnings):
+    """
+    Context manager for silencing bokeh validation warnings.
+    """
+    for warning in warnings:
+        silence(warning)
+    try:
+        yield
+    finally:
+        for warning in warnings:
+            silence(warning, False)
+
+
 def empty_plot(width, height):
     """
     Creates an empty and invisible plot of the specified size.