Explicitly pass backend

streamjoy/renderers.py

@@ -131,9 +131,7 @@ def default_holoviews_renderer(
         The rendered HoloViews Element.
     """
     import holoviews as hv
-
-    backend = kwargs.get("backend", "bokeh")
-    hv.extension(backend)
+    backend = kwargs.get("backend", hv.Store.current_backend)
 
     clims = kwargs.pop("clims", {})
     for hv_el in hv_obj.traverse(full_breadth=False):
@@ -142,10 +140,12 @@ def default_holoviews_renderer(
         except IndexError:
             continue
         if vdim in clims:
-            hv_el.opts(clim=clims[vdim])
+            hv_el.opts(clim=clims[vdim], backend=backend)
 
     if backend == "bokeh":
         kwargs["toolbar"] = None
+    elif backend == "matplotlib":
+        kwargs["cbar_extend"] = kwargs.get("cbar_extend", "both")
     hv_obj.opts(**kwargs)
 
     return hv_obj

streamjoy/serializers.py

@@ -302,8 +302,7 @@ def serialize_holoviews(
     """
     import holoviews as hv
 
-    backend = hv.Store.current_backend
-    hv.extension(backend)
+    backend = kwargs.get("backend", hv.Store.current_backend)
 
     def _select_element(hv_obj, key):
         try:
@@ -332,7 +331,10 @@ def _select_element(hv_obj, key):
     if len(kdims) > 1:
         raise ValueError("Can only handle 1D HoloViews objects.")
 
-    resources = [_select_element(hv_obj, key).opts(title=str(key)) for key in keys]
+    resources = [
+        _select_element(hv_obj, key).opts(title=str(key))
+        for key in keys
+    ]
 
     renderer_kwargs = renderer_kwargs or {}
     renderer_kwargs.update(_utils.pop_from_cls(stream_cls, kwargs))
@@ -353,6 +355,7 @@ def _select_element(hv_obj, key):
                     array = hv_el.dimension_values(vdim)
                     clim = (np.nanmin(array), np.nanmax(array))
                     clims[vdim] = clim
+
         renderer_kwargs.update(
             backend=backend,
             clims=clims,

streamjoy/wrappers.py

@@ -99,9 +99,7 @@ def wrapper(renderer):
         def wrapped(*args, **kwargs) -> Path | BytesIO:
             import holoviews as hv
 
-            backend = kwargs.get("backend", "bokeh")
-            hv.extension(backend)
-
+            backend = kwargs.get("backend", hv.Store.current_backend)
             output = renderer(*args, **kwargs)
 
             hv_obj = output
@@ -129,7 +127,7 @@ def wrapped(*args, **kwargs) -> Path | BytesIO:
                     service=Service(ChromeDriverManager().install()), options=options
                 ) as webdriver:
                     image = get_screenshot_as_png(
-                        hv.render(hv_obj, backend="bokeh"), driver=webdriver
+                        hv.render(hv_obj, backend=backend), driver=webdriver
                     )
                     if fsspec_fs:
                         with fsspec_fs.open(uri, "wb") as f:

tests/test_streams.py

@@ -12,6 +12,7 @@ def _assert_stream_and_props(self, sj, stream_cls):
         buf = sj.write()
         props = improps(buf)
         props.n_images == 3
+        return props
 
     def test_from_pandas(self, stream_cls, df):
         sj = stream_cls.from_pandas(df)
@@ -54,6 +55,20 @@ def test_fsspec_fs(self, stream_cls, df, fsspec_fs):
         sj = stream_cls.from_pandas(df, fsspec_fs=fsspec_fs)
         self._assert_stream_and_props(sj, stream_cls)
 
+    def test_holoviews_matplotlib_backend(self, stream_cls, ds):
+        sj = stream_cls.from_holoviews(
+            ds.hvplot("lon", "lat", fig_size=200, backend="matplotlib")
+        )
+        props = self._assert_stream_and_props(sj, stream_cls)
+        assert props.shape[1] == 300
+
+    def test_holoviews_bokeh_backend(self, stream_cls, ds):
+        sj = stream_cls.from_holoviews(
+            ds.hvplot("lon", "lat", width=300, backend="bokeh")
+        )
+        props = self._assert_stream_and_props(sj, stream_cls)
+        assert props.shape[1] == 300
+
 
 class TestGifStream(AbstractTestMediaStream):
     @pytest.fixture(scope="class")