Add hatch custom plugin to download the CSS

hatch_build.py

@@ -0,0 +1,51 @@
+import os
+import sys
+
+from hatchling.builders.hooks.plugin.interface import BuildHookInterface
+from urllib.request import urlopen
+
+
+JUPYTERLAB_APPUTILS_VERSION = "3.2.8"
+JUPYTERLAB_THEME_LIGHT_VERSION = "3.2.8"
+
+CSS_FILES = [
+    (
+        f"https://unpkg.com/@jupyterlab/apputils@{JUPYTERLAB_APPUTILS_VERSION}/style/materialcolors.css",
+        "materialcolors.css",
+    ),
+    (
+        f"https://unpkg.com/@jupyterlab/theme-light-extension@{JUPYTERLAB_THEME_LIGHT_VERSION}/style/variables.css",
+        "labvariables.css",
+    ),
+]
+
+
+class CustomBuildHook(BuildHookInterface):
+    def initialize(self, version, build_data):
+        for template_name in ["classic", "reveal"]:
+            for url, filename in CSS_FILES:
+                directory = os.path.join(
+                    "share", "jupyter", "voila", "templates", template_name, "static"
+                )
+                dest = os.path.join(directory, filename)
+                if not os.path.exists(directory):
+                    os.makedirs(directory)
+                if not os.path.exists(".git") and os.path.exists(dest):
+                    # not running from git, nothing to do
+                    return
+                print("Downloading CSS: %s" % url)
+                try:
+                    css = urlopen(url).read()
+                except Exception as e:
+                    msg = "Failed to download css from %s: %s" % (url, e)
+                    print(msg, file=sys.stderr)
+
+                    if os.path.exists(dest):
+                        print("Already have CSS: %s, moving on." % dest)
+                    else:
+                        raise OSError("Need CSS to proceed.")
+                    return
+
+                with open(dest, "wb") as f:
+                    f.write(css)
+                print("Downloaded Notebook CSS to %s" % dest)

pyproject.toml

@@ -83,6 +83,9 @@ artifacts = [
     "share/jupyter/voila/templates"
 ]
 
+[tool.hatch.build.hooks.custom]
+path = "hatch_build.py"
+
 [tool.hatch.build.targets.wheel.shared-data]
 "etc/jupyter" = "etc/jupyter"
 "voila/static" = "share/jupyter/nbextensions/voila"
@@ -102,9 +105,17 @@ dependencies = [
 build-function = "hatch_jupyter_builder.npm_builder"
 ensured-targets = [
     "voila/labextension/static/style.js",
+    "share/jupyter/voila/templates/classic/static/materialcolors.css",
+    "share/jupyter/voila/templates/classic/static/labvariables.css",
+    "share/jupyter/voila/templates/reveal/static/materialcolors.css",
+    "share/jupyter/voila/templates/reveal/static/labvariables.css",
 ]
 skip-if-exists = [
     "voila/labextension/static/style.js",
+    "share/jupyter/voila/templates/classic/static/materialcolors.css",
+    "share/jupyter/voila/templates/classic/static/labvariables.css",
+    "share/jupyter/voila/templates/reveal/static/materialcolors.css",
+    "share/jupyter/voila/templates/reveal/static/labvariables.css",
 ]
 
 [tool.hatch.build.hooks.jupyter-builder.editable-build-kwargs]