Improve handling of index argument (#3221)

* Improve handling of index argument

* Fix flake

examples/user_guide/Deploy_and_Export.ipynb

@@ -373,13 +373,11 @@
     "                            A list of request cookies to make available in the\n",
     "                            session context (by default all cookies are included).\n",
     "      --session-ids MODE    One of: unsigned, signed, or external-signed\n",
-    "      --index INDEX         Path to a template to use for the site index\n",
+    "      --index INDEX         Path to a template to use for the site index or\n",
+    "                            an app to serve at the root.\n",
     "      --disable-index       Do not use the default index on the root path\n",
     "      --disable-index-redirect\n",
     "                            Do not redirect to running app from root path\n",
-    "      --default-app FILENAME\n",
-    "                            The app to redirect to from the root. When enabled\n",
-    "                            no index is served.\n",
     "      --num-procs N         Number of worker processes for an app. Using 0 will\n",
     "                            autodetect number of cores (defaults to 1)\n",
     "      --num-threads N       Number of threads to launch in a ThreadPoolExecutor which\n",

panel/command/serve.py

@@ -188,6 +188,19 @@ class Serve(_BkServe):
         ))
     )
 
+    # Supported file extensions
+    _extensions = ['.py']
+
+    def customize_applications(self, args, applications):
+        if args.index and not args.index.endswith('.html'):
+            index = args.index.split(os.path.sep)[-1]
+            for ext in self._extensions:
+                if index.endswith(ext):
+                    index = index[:-len(ext)]
+            if f'/{index}' in applications:
+                applications['/'] = applications.pop(f'/{index}')
+        return super().customize_applications(args, applications)
+
     def customize_kwargs(self, args, server_kwargs):
         '''Allows subclasses to customize ``server_kwargs``.
 
@@ -211,12 +224,20 @@ def customize_kwargs(self, args, server_kwargs):
             else:
                 files.append(f)
 
-        if args.index and not args.index.endswith('.html') and not any(f.endswith(args.index) for f in files):
-            raise ValueError("The --index argument must either specify a jinja2 "
-                             "template with a .html file extension or select one "
-                             "of the applications being served as the default. "
-                             f"The specified application {args.index!r} could "
-                             "not be found.")
+        if args.index and not args.index.endswith('.html'):
+            found = False
+            for ext in self._extensions:
+                index = args.index if args.index.endswith(ext) else f'{args.index}{ext}'
+                if any(f.endswith(index) for f in files):
+                    found = True
+            if not found:
+                raise ValueError(
+                    "The --index argument must either specify a jinja2 "
+                    "template with a .html file extension or select one "
+                    "of the applications being served as the default. "
+                    f"The specified application {index!r} could not be "
+                    "found."
+                )
 
         # Handle tranquilized functions in the supplied functions
         if args.rest_provider in REST_PROVIDERS:

panel/io/server.py

@@ -35,10 +35,9 @@
 from bokeh.embed.util import RenderItem
 from bokeh.io import curdoc
 from bokeh.server.server import Server
-from bokeh.server.urls import per_app_patterns, toplevel_patterns
+from bokeh.server.urls import per_app_patterns
 from bokeh.server.views.autoload_js_handler import AutoloadJsHandler as BkAutoloadJsHandler
 from bokeh.server.views.doc_handler import DocHandler as BkDocHandler
-from bokeh.server.views.root_handler import RootHandler as BkRootHandler
 from bokeh.server.views.static_handler import StaticHandler
 
 # Tornado imports
@@ -272,19 +271,6 @@ async def get(self, *args, **kwargs):
 
 per_app_patterns[3] = (r'/autoload.js', AutoloadJsHandler)
 
-class RootHandler(BkRootHandler):
-
-    @authenticated
-    async def get(self, *args, **kwargs):
-        if self.index and not self.index.endswith('.html'):
-            prefix = "" if self.prefix is None else self.prefix
-            redirect_to = prefix + '.'.join(self.index.split('.')[:-1])
-            self.redirect(redirect_to)
-        await super().get(*args, **kwargs)
-
-toplevel_patterns[0] = (r'/?', RootHandler)
-bokeh.server.tornado.RootHandler = RootHandler
-
 def modify_document(self, doc):
     from bokeh.io.doc import set_curdoc as bk_set_curdoc
     from ..config import config