Merge pull request #248 from Zsailer/extension-loading

Add new extension manager API

examples/simple/pyproject.toml

@@ -0,0 +1,3 @@
+[build-system]
+requires = ["jupyter_packaging~=0.5.0", "setuptools>=40.8.0", "wheel"]
+build-backend = "setuptools.build_meta"

examples/simple/setup.py

@@ -1,40 +1,46 @@
-import os, setuptools
-from setuptools import find_packages
+import os
+from setuptools import setup
+from jupyter_packaging import create_cmdclass
+
 
 VERSION = '0.0.1'
 
+
 def get_data_files():
     """Get the data files for the package.
     """
     data_files = [
-        ('etc/jupyter/jupyter_server_config.d', ['etc/jupyter/jupyter_server_config.d/simple_ext1.json']),
-        ('etc/jupyter/jupyter_server_config.d', ['etc/jupyter/jupyter_server_config.d/simple_ext2.json']),
-        ('etc/jupyter/jupyter_server_config.d', ['etc/jupyter/jupyter_server_config.d/simple_ext11.json']),
+        ('etc/jupyter/jupyter_server_config.d', 'etc/jupyter/jupyter_server_config.d/', '*.json'),
     ]
     def add_data_files(path):
         for (dirpath, dirnames, filenames) in os.walk(path):
             if filenames:
-                data_files.append((dirpath, [os.path.join(dirpath, filename) for filename in filenames]))
+                paths = [(dirpath, dirpath, filename) for filename in filenames]
+                data_files.extend(paths)
     # Add all static and templates folders.
     add_data_files('simple_ext1/static')
     add_data_files('simple_ext1/templates')
     add_data_files('simple_ext2/static')
     add_data_files('simple_ext2/templates')
     return data_files
 
-setuptools.setup(
+
+cmdclass = create_cmdclass(
+    data_files_spec=get_data_files()
+)
+
+setup_args = dict(
     name = 'jupyter_server_example',
     version = VERSION,
     description = 'Jupyter Server Example',
     long_description = open('README.md').read(),
-    packages = find_packages(),
     python_requires = '>=3.5',
     install_requires = [
         'jupyter_server',
         'jinja2',
     ],
     include_package_data=True,
-    data_files = get_data_files(),
+    cmdclass = cmdclass,
     entry_points = {
         'console_scripts': [
              'jupyter-simple-ext1 = simple_ext1.application:main',
@@ -43,3 +49,7 @@ def add_data_files(path):
         ]
     },
 )
+
+
+if __name__ == '__main__':
+    setup(**setup_args)

jupyter_server/config_manager.py

@@ -118,7 +118,6 @@ def set(self, section_name, data):
         # Generate the JSON up front, since it could raise an exception,
         # in order to avoid writing half-finished corrupted data to disk.
         json_content = json.dumps(data, indent=2)
-
         if PY3:
             f = io.open(filename, 'w', encoding='utf-8')
         else:

jupyter_server/extension/application.py

@@ -144,12 +144,27 @@ class method. This method can be set as a entry_point in
     # side-by-side when launched directly.
     load_other_extensions = True
 
+    # A useful class property that subclasses can override to
+    # configure the underlying Jupyter Server when this extension
+    # is launched directly (using its `launch_instance` method).
+    serverapp_config = {
+        "open_browser": True
+    }
+
     # The extension name used to name the jupyter config
     # file, jupyter_{name}_config.
     # This should also match the jupyter subcommand used to launch
     # this extension from the CLI, e.g. `jupyter {name}`.
     name = None
 
+    @classmethod
+    def get_extension_package(cls):
+        return cls.__module__.split('.')[0]
+
+    @classmethod
+    def get_extension_point(cls):
+        return cls.__module__
+
     # Extension URL sets the default landing page for this extension.
     extension_url = "/"
 
@@ -158,6 +173,9 @@ class method. This method can be set as a entry_point in
         ServerApp,
     ]
 
+    # A ServerApp is not defined yet, but will be initialized below.
+    serverapp = None
+
     @property
     def static_url_prefix(self):
         return "/static/{name}/".format(
@@ -281,28 +299,17 @@ def _prepare_templates(self):
         self.initialize_templates()
 
     @classmethod
-    def initialize_server(cls, argv=[], load_other_extensions=True, **kwargs):
-        """Creates an instance of ServerApp where this extension is enabled
-        (superceding disabling found in other config from files).
-
-        This is necessary when launching the ExtensionApp directly from
-        the `launch_instance` classmethod.
-        """
-        # The ExtensionApp needs to add itself as enabled extension
-        # to the jpserver_extensions trait, so that the ServerApp
-        # initializes it.
-        config = Config({
+    def _jupyter_server_config(cls):
+        base_config = {
             "ServerApp": {
-                "jpserver_extensions": {cls.name: True},
-                "open_browser": cls.open_browser,
+                "jpserver_extensions": {cls.get_extension_package(): True},
                 "default_url": cls.extension_url
             }
-        })
-        serverapp = ServerApp.instance(**kwargs, argv=[], config=config)
-        serverapp.initialize(argv=argv, find_extensions=load_other_extensions)
-        return serverapp
+        }
+        base_config["ServerApp"].update(cls.serverapp_config)
+        return base_config
 
-    def link_to_serverapp(self, serverapp):
+    def _link_jupyter_server_extension(self, serverapp):
         """Link the ExtensionApp to an initialized ServerApp.
 
         The ServerApp is stored as an attribute and config
@@ -315,7 +322,7 @@ def link_to_serverapp(self, serverapp):
         # Load config from an ExtensionApp's config files.
         self.load_config_file()
         # ServerApp's config might have picked up
-        # CLI config for the ExtensionApp. We call
+        # config for the ExtensionApp. We call
         # update_config to update ExtensionApp's
         # traits with these values found in ServerApp's
         # config.
@@ -330,6 +337,22 @@ def link_to_serverapp(self, serverapp):
         # i.e. ServerApp traits <--- ExtensionApp config
         self.serverapp.update_config(self.config)
 
+    @classmethod
+    def initialize_server(cls, argv=[], load_other_extensions=True, **kwargs):
+        """Creates an instance of ServerApp where this extension is enabled
+        (superceding disabling found in other config from files).
+
+        This is necessary when launching the ExtensionApp directly from
+        the `launch_instance` classmethod.
+        """
+        # The ExtensionApp needs to add itself as enabled extension
+        # to the jpserver_extensions trait, so that the ServerApp
+        # initializes it.
+        config = Config(cls._jupyter_server_config())
+        serverapp = ServerApp.instance(**kwargs, argv=[], config=config)
+        serverapp.initialize(argv=argv, find_extensions=load_other_extensions)
+        return serverapp
+
     def initialize(self):
         """Initialize the extension app. The
         corresponding server app and webapp should already
@@ -341,7 +364,7 @@ def initialize(self):
         3) Points Tornado Webapp to templates and
         static assets.
         """
-        if not hasattr(self, 'serverapp'):
+        if not self.serverapp:
             msg = (
                 "This extension has no attribute `serverapp`. "
                 "Try calling `.link_to_serverapp()` before calling "
@@ -374,12 +397,14 @@ def _load_jupyter_server_extension(cls, serverapp):
         """Initialize and configure this extension, then add the extension's
         settings and handlers to the server's web application.
         """
+        extension_manager = serverapp.extension_manager
         try:
             # Get loaded extension from serverapp.
-            extension = serverapp._enabled_extensions[cls.name]
+            point = extension_manager.extension_points[cls.name]
+            extension = point.app
         except KeyError:
             extension = cls()
-            extension.link_to_serverapp(serverapp)
+            extension._link_jupyter_server_extension(serverapp)
         extension.initialize()
         return extension
 

jupyter_server/extension/config.py

@@ -0,0 +1,57 @@
+
+from jupyter_server.services.config.manager import ConfigManager
+
+
+DEFAULT_SECTION_NAME = "jupyter_server_config"
+
+
+class ExtensionConfigManager(ConfigManager):
+    """A manager class to interface with Jupyter Server Extension config
+    found in a `config.d` folder. It is assumed that all configuration
+    files in this directory are JSON files.
+    """
+    def get_jpserver_extensions(
+        self,
+        section_name=DEFAULT_SECTION_NAME
+    ):
+        """Return the jpserver_extensions field from all
+        config files found."""
+        data = self.get(section_name)
+        return (
+            data
+            .get("ServerApp", {})
+            .get("jpserver_extensions", {})
+        )
+
+    def enabled(
+        self,
+        name,
+        section_name=DEFAULT_SECTION_NAME,
+        include_root=True
+    ):
+        """Is the extension enabled?"""
+        extensions = self.get_jpserver_extensions(section_name)
+        try:
+            return extensions[name]
+        except KeyError:
+            return False
+
+    def enable(self, name):
+        data = {
+            "ServerApp": {
+                "jpserver_extensions": {
+                    name: True
+                }
+            }
+        }
+        self.update(name, data)
+
+    def disable(self, name):
+        data = {
+            "ServerApp": {
+                "jpserver_extensions": {
+                    name: False
+                }
+            }
+        }
+        self.update(name, data)