Move hooks to VoilaConfiguration

Author: trungleduc

docs/customize.md

@@ -309,8 +309,8 @@ def page_config_hook_function(current_page_config,**kwargs):
    """Modify the current_page_config"""
    return new_page_config
 
-c.Voila.prelaunch_hook = hook_function
-c.Voila.page_config_hook = page_config_hook
+c.VoilaConfiguration.prelaunch_hook = hook_function
+c.VoilaConfiguration.page_config_hook = page_config_hook
 
 ```
 
@@ -374,18 +374,18 @@ from voila.config import VoilaConfiguration
 # customize config how you like
 config = VoilaConfiguration()
 
+# set the prelaunch hook
+config.prelaunch_hook = parameterize_with_papermill
+
+# set the page config hook
+config.config_page_hook = page_config_hook
+
 # create a voila instance
 app = Voila()
 
 # set the config
 app.voila_configuration = config
 
-# set the prelaunch hook
-app.prelaunch_hook = parameterize_with_papermill
-
-# set the page config hook
-app.config_page_hook = page_config_hook
-
 # launch
 app.start()
 ```

voila/app.py

@@ -70,7 +70,6 @@
 
 from traitlets import (
     Bool,
-    Callable,
     Dict,
     Integer,
     List,
@@ -193,6 +192,8 @@ class Voila(Application):
         "theme": "VoilaConfiguration.theme",
         "classic_tree": "VoilaConfiguration.classic_tree",
         "kernel_spec_manager_class": "VoilaConfiguration.kernel_spec_manager_class",
+        "prelaunch_hook": "VoilaConfiguration.prelaunch_hook",  # For backward compatibility
+        "page_config_hook": "VoilaConfiguration.page_config_hook",
     }
     if JUPYTER_SERVER_2:
         aliases = {**aliases, "token": "Voila.token"}
@@ -325,54 +326,6 @@ class Voila(Application):
         ),
     )
 
-    prelaunch_hook = Callable(
-        default_value=None,
-        allow_none=True,
-        config=True,
-        help=_(
-            """A function that is called prior to the launch of a new kernel instance
-            when a user visits the voila webpage. Used for custom user authorization
-            or any other necessary pre-launch functions.
-
-            Should be of the form:
-
-            def hook(req: tornado.web.RequestHandler,
-                    notebook: nbformat.NotebookNode,
-                    cwd: str)
-
-            Although most customizations can leverage templates, if you need access
-            to the request object (e.g. to inspect cookies for authentication),
-            or to modify the notebook itself (e.g. to inject some custom structure,
-            although much of this can be done by interacting with the kernel
-            in javascript) the prelaunch hook lets you do that.
-            """
-        ),
-    )
-
-    page_config_hook = Callable(
-        default_value=None,
-        allow_none=True,
-        config=True,
-        help=_(
-            """A function that is called to modify the page config for a given notebook.
-            Should be of the form:
-
-            def page_config_hook(
-                current_page_config: Dict[str, Any],
-                base_url: str,
-                settings: Dict[str, Any],
-                log: Logger,
-                voila_configuration: VoilaConfiguration,
-                notebook_path: str
-            ) -> Dict[str, Any]:
-
-            The hook receives the default page_config dictionary and all its parameters, it should
-            return a dictionary that will be passed to the template as the `page_config` variable
-            and the NotebookRenderer. This can be used to pass custom configuration.
-            """
-        ),
-    )
-
     if JUPYTER_SERVER_2:
         cookie_secret = Bytes(
             b"",
@@ -632,14 +585,14 @@ def init_settings(self) -> Dict:
         preheat_kernel: bool = self.voila_configuration.preheat_kernel
         pool_size: int = self.voila_configuration.default_pool_size
 
-        if preheat_kernel and self.prelaunch_hook:
+        if preheat_kernel and self.voila_configuration.prelaunch_hook:
             raise Exception("`preheat_kernel` and `prelaunch_hook` are incompatible")
 
         kernel_manager_class = voila_kernel_manager_factory(
             self.voila_configuration.multi_kernel_manager_class,
             preheat_kernel,
             pool_size,
-            page_config_hook=self.page_config_hook,
+            page_config_hook=self.voila_configuration.page_config_hook,
         )
         self.kernel_manager = kernel_manager_class(
             parent=self,
@@ -814,8 +767,6 @@ def init_handlers(self) -> List:
                         "template_paths": self.template_paths,
                         "config": self.config,
                         "voila_configuration": self.voila_configuration,
-                        "prelaunch_hook": self.prelaunch_hook,
-                        "page_config_hook": self.page_config_hook,
                     },
                 )
             )
@@ -826,18 +777,12 @@ def init_handlers(self) -> List:
                     (
                         self.server_url,
                         TornadoVoilaTreeHandler,
-                        {
-                            "voila_configuration": self.voila_configuration,
-                            "page_config_hook": self.page_config_hook,
-                        },
+                        {"voila_configuration": self.voila_configuration},
                     ),
                     (
                         url_path_join(self.server_url, r"/voila/tree" + path_regex),
                         TornadoVoilaTreeHandler,
-                        {
-                            "voila_configuration": self.voila_configuration,
-                            "page_config_hook": self.page_config_hook,
-                        },
+                        {"voila_configuration": self.voila_configuration},
                     ),
                     (
                         url_path_join(self.server_url, r"/voila/render/(.*)"),
@@ -846,8 +791,6 @@ def init_handlers(self) -> List:
                             "template_paths": self.template_paths,
                             "config": self.config,
                             "voila_configuration": self.voila_configuration,
-                            "prelaunch_hook": self.prelaunch_hook,
-                            "page_config_hook": self.page_config_hook,
                         },
                     ),
                     # On serving a directory, expose the content handler.

voila/configuration.py

@@ -8,7 +8,7 @@
 #############################################################################
 
 import traitlets.config
-from traitlets import Bool, Dict, Enum, Int, List, Type, Unicode, validate
+from traitlets import Bool, Callable, Dict, Enum, Int, List, Type, Unicode, validate
 
 from warnings import warn
 
@@ -217,3 +217,47 @@ def _valid_file_blacklist(self, proposal):
         config=True,
         help="""Whether or not voila should attempt to fix and resolve a notebooks kernelspec metadata""",
     )
+
+    prelaunch_hook = Callable(
+        default_value=None,
+        allow_none=True,
+        config=True,
+        help="""A function that is called prior to the launch of a new kernel instance
+            when a user visits the voila webpage. Used for custom user authorization
+            or any other necessary pre-launch functions.
+
+            Should be of the form:
+
+            def hook(req: tornado.web.RequestHandler,
+                    notebook: nbformat.NotebookNode,
+                    cwd: str)
+
+            Although most customizations can leverage templates, if you need access
+            to the request object (e.g. to inspect cookies for authentication),
+            or to modify the notebook itself (e.g. to inject some custom structure,
+            although much of this can be done by interacting with the kernel
+            in javascript) the prelaunch hook lets you do that.
+            """,
+    )
+
+    page_config_hook = Callable(
+        default_value=None,
+        allow_none=True,
+        config=True,
+        help="""A function that is called to modify the page config for a given notebook.
+            Should be of the form:
+
+            def page_config_hook(
+                current_page_config: Dict[str, Any],
+                base_url: str,
+                settings: Dict[str, Any],
+                log: Logger,
+                voila_configuration: VoilaConfiguration,
+                notebook_path: str
+            ) -> Dict[str, Any]:
+
+            The hook receives the default page_config dictionary and all its parameters, it should
+            return a dictionary that will be passed to the template as the `page_config` variable
+            and the NotebookRenderer. This can be used to pass custom configuration.
+            """,
+    )

voila/handler.py

@@ -72,8 +72,8 @@ def initialize(self, **kwargs):
         self.template_paths = kwargs.pop("template_paths", [])
         self.traitlet_config = kwargs.pop("config", None)
         self.voila_configuration: VoilaConfiguration = kwargs["voila_configuration"]
-        self.prelaunch_hook = kwargs.get("prelaunch_hook", None)
-        self.page_config_hook = kwargs.get("page_config_hook", None)
+        self.prelaunch_hook = self.voila_configuration.prelaunch_hook
+        self.page_config_hook = self.voila_configuration.page_config_hook
 
         # we want to avoid starting multiple kernels due to template mistakes
         self.kernel_started = False

voila/notebook_renderer.py

@@ -45,7 +45,7 @@ def __init__(self, **kwargs):
         self.config_manager = kwargs.get("config_manager")
         self.contents_manager = kwargs.get("contents_manager")
         self.kernel_spec_manager = kwargs.get("kernel_spec_manager")
-        self.prelaunch_hook = kwargs.get("prelaunch_hook")
+        self.prelaunch_hook = self.voila_configuration.prelaunch_hook
         self.base_url = kwargs.get("base_url")
         self.page_config = deepcopy(kwargs.get("page_config"))
         self.default_kernel_name = "python3"

voila/server_extension.py

@@ -81,8 +81,6 @@ def _load_jupyter_server_extension(server_app: ServerApp):
     voila_configuration = VoilaConfiguration(
         parent=server_app, config=load_config_file()
     )
-    page_config_hook = voila_configuration.config.Voila.get("page_config_hook", None)
-    prelaunch_hook = voila_configuration.config.Voila.get("prelaunch_hook", None)
 
     template_name = voila_configuration.template
     template_paths = collect_template_paths(["voila", "nbconvert"], template_name)
@@ -104,6 +102,8 @@ def _load_jupyter_server_extension(server_app: ServerApp):
     host_pattern = ".*$"
     base_url = url_path_join(web_app.settings["base_url"])
 
+    tree_handler_conf = {"voila_configuration": voila_configuration}
+
     themes_dir = pjoin(get_data_dir(), "themes")
     web_app.add_handlers(
         host_pattern,
@@ -115,25 +115,17 @@ def _load_jupyter_server_extension(server_app: ServerApp):
                     "config": server_app.config,
                     "template_paths": template_paths,
                     "voila_configuration": voila_configuration,
-                    "prelaunch_hook": prelaunch_hook,
-                    "page_config_hook": page_config_hook,
                 },
             ),
             (
                 url_path_join(base_url, "/voila"),
                 TornadoVoilaTreeHandler,
-                {
-                    "voila_configuration": voila_configuration,
-                    "page_config_hook": page_config_hook,
-                },
+                tree_handler_conf,
             ),
             (
                 url_path_join(base_url, "/voila/tree" + path_regex),
                 TornadoVoilaTreeHandler,
-                {
-                    "voila_configuration": voila_configuration,
-                    "page_config_hook": page_config_hook,
-                },
+                tree_handler_conf,
             ),
             (
                 url_path_join(base_url, "/voila/templates/(.*)"),
@@ -170,7 +162,7 @@ def _load_jupyter_server_extension(server_app: ServerApp):
             (
                 url_path_join(base_url, r"/voila/api/contents%s" % path_regex),
                 VoilaContentsHandler,
-                {"voila_configuration": voila_configuration},
+                tree_handler_conf,
             ),
         ],
     )

voila/tornado/treehandler.py

@@ -23,7 +23,7 @@
 class TornadoVoilaTreeHandler(VoilaTreeHandler):
     def initialize(self, **kwargs):
         super().initialize(**kwargs)
-        self.page_config_hook = kwargs.get("page_config_hook", None)
+        self.page_config_hook = self.voila_configuration.page_config_hook
 
     @web.authenticated
     async def get(self, path=""):

voila/voila_kernel_manager.py

@@ -12,7 +12,7 @@
 import os
 import re
 from pathlib import Path
-from typing import Awaitable, Callable
+from typing import Awaitable, Callable, Optional
 from typing import Dict as TypeDict
 from typing import List as TypeList
 from typing import Tuple, Type, TypeVar, Union
@@ -37,7 +37,7 @@ def voila_kernel_manager_factory(
     base_class: Type[T],
     preheat_kernel: bool,
     default_pool_size: int,
-    page_config_hook: Callable = None,
+    page_config_hook: Optional[Callable] = None,
 ) -> T:
     """
     Decorator used to make a normal kernel manager compatible with pre-heated