Open formgrader with a local configuration file (#1859)

* Allow formgrader to update its config from the current directory in lab

* Restore the config to avoid confusion

* Initialize configuration only if necessary

* Add a debuf flag to FormgraderExtension to display the current configuration in formgrader UI

* Add a setting to enable/disable the local formgrader

* Avoid loading CWD config when API is called too

* Fix UI tests

* Update documentation

* Add a warning about using it with several users on the same Jupyterlab instance, and show the configuration by default in formgrader

* Add tests on local formgrader and increase time for doc test

* Fix ui-tests on notebook

* Skip test on formgrader exchange on windows

nbgrader/apps/baseapp.py

@@ -64,6 +64,8 @@ class NbGrader(JupyterApp):
     aliases = nbgrader_aliases
     flags = nbgrader_flags
 
+    load_cwd_config = True
+
     _log_formatter_cls = LogFormatter
 
     @default("log_level")
@@ -313,10 +315,13 @@ def excepthook(self, etype, evalue, tb):
         format_excepthook(etype, evalue, tb)
 
     @catch_config_error
-    def initialize(self, argv: TypingList[str] = None) -> None:
+    def initialize(self, argv: TypingList[str] = None, root: str = '') -> None:
         self.update_config(self.build_extra_config())
         self.init_syspath()
-        self.coursedir = CourseDirectory(parent=self)
+        if root:
+            self.coursedir = CourseDirectory(parent=self, root=root)
+        else:
+            self.coursedir = CourseDirectory(parent=self)
         super(NbGrader, self).initialize(argv)
 
         # load config that is in the coursedir directory
@@ -355,16 +360,18 @@ def load_config_file(self, **kwargs: Any) -> None:
             paths = [os.path.abspath("{}.py".format(self.config_file))]
         else:
             config_dir = self.config_file_paths.copy()
-            config_dir.insert(0, os.getcwd())
+            if self.load_cwd_config:
+                config_dir.insert(0, os.getcwd())
             paths = [os.path.join(x, "{}.py".format(self.config_file_name)) for x in config_dir]
 
         if not any(os.path.exists(x) for x in paths):
             self.log.warning("No nbgrader_config.py file found (rerun with --debug to see where nbgrader is looking)")
 
         super(NbGrader, self).load_config_file(**kwargs)
 
-        # Load also config from current working directory
-        super(JupyterApp, self).load_config_file(self.config_file_name, os.getcwd())
+        if (self.load_cwd_config):
+            # Load also config from current working directory
+            super(JupyterApp, self).load_config_file(self.config_file_name, os.getcwd())
 
     def start(self) -> None:
         super(NbGrader, self).start()

nbgrader/docs/source/build_docs.py

@@ -5,6 +5,7 @@
 import shutil
 import sys
 import nbgrader.apps
+import nbgrader.server_extensions.formgrader
 
 from textwrap import dedent
 from clear_docs import run, clear_notebooks
@@ -92,6 +93,7 @@ def autogen_config(root):
 
     print('Generating example configuration file')
     config = nbgrader.apps.NbGraderApp().document_config_options()
+    config += nbgrader.server_extensions.formgrader.formgrader.FormgradeExtension().document_config_options()
     destination = os.path.join(root, 'configuration', 'config_options.rst')
     with open(destination, 'w') as f:
         f.write(header)

nbgrader/docs/source/configuration/nbgrader_config.rst

@@ -65,8 +65,34 @@ For example, the ``nbgrader_config.py`` that the notebook knows about could be p
 
 Then you would additionally have a config file at ``/path/to/course/directory/nbgrader_config.py``.
 
+Use Case 3: using config from a specific sub directory
+------------------------------------------------------
 
-Use Case 3: nbgrader and JupyterHub
+.. warning::
+
+    This option should not be used with a multiuser Jupyterlab instance, as it modifies
+    certain objects in the running instance, and can probably prevent other users
+    from using *formgrader* correctly. Also, if you have a JupyterHub installation,
+    you should use the settings described in the following section.
+
+You may need to use a dedicated configuration file for each course without configuring
+JupyterHub for all courses. In this case, the config file used will be the one from the
+current directory in the filebrowser panel, instead of the one from the directory where
+the jupyter server started.
+
+This option is not enabled by default. It can be enabled by using the settings panel:
+*Nbgrader -> Formgrader* and check *Allow local nbgrader config file*.
+
+A new item is displayed in the *nbgrader* menu (or in the command palette), to open
+formgrader from the local director: *Formgrader (local)*.
+
+.. warning::
+
+    If paths are used in the configuration file, note that the root of the relative
+    paths will always be the directory where the jupyter server was started, and not
+    the directory containing the ``nbgrader_config.py`` file.
+
+Use Case 4: nbgrader and JupyterHub
 -----------------------------------
 
 .. seealso::

nbgrader/server_extensions/formgrader/base.py

@@ -16,15 +16,15 @@ def base_url(self):
 
     @property
     def db_url(self):
-        return self.settings['nbgrader_coursedir'].db_url
+        return self.coursedir.db_url
 
     @property
     def url_prefix(self):
         return self.settings['nbgrader_formgrader'].url_prefix
 
     @property
     def coursedir(self):
-        return self.settings['nbgrader_coursedir']
+        return self.settings['nbgrader_formgrader'].coursedir
 
     @property
     def authenticator(self):

nbgrader/server_extensions/formgrader/formgrader.py

@@ -1,13 +1,13 @@
 # coding: utf-8
 
 import os
+from textwrap import dedent
 
 from nbconvert.exporters import HTMLExporter
-from traitlets import default
+from traitlets import Bool, default
 from tornado import web
 from jinja2 import Environment, FileSystemLoader
 from jupyter_server.utils import url_path_join as ujoin
-from jupyter_core.paths import jupyter_config_path
 
 from . import handlers, apihandlers
 from ...apps.baseapp import NbGrader
@@ -18,6 +18,17 @@ class FormgradeExtension(NbGrader):
     name = u'formgrade'
     description = u'Grade a notebook using an HTML form'
 
+    debug = Bool(
+        True,
+        help=dedent(
+            """
+            Whether to display the loaded configuration in the 'Formgrader ->
+            Manage Assignments' panel. This can help debugging some misconfiguration
+            when using several files.
+            """
+        )
+    ).tag(config=True)
+
     @property
     def root_dir(self):
         return self._root_dir
@@ -33,10 +44,9 @@ def url_prefix(self):
         return relpath
 
     def load_config(self):
-        paths = jupyter_config_path()
-        paths.insert(0, os.getcwd())
         app = NbGrader()
-        app.config_file_paths.append(paths)
+        app.load_cwd_config = self.load_cwd_config
+        app.config_dir = self.config_dir
         app.load_config_file()
 
         return app.config
@@ -72,13 +82,13 @@ def init_tornado_settings(self, webapp):
         # Configure the formgrader settings
         tornado_settings = dict(
             nbgrader_formgrader=self,
-            nbgrader_coursedir=self.coursedir,
             nbgrader_authenticator=self.authenticator,
             nbgrader_exporter=HTMLExporter(config=self.config),
             nbgrader_gradebook=None,
             nbgrader_db_url=self.coursedir.db_url,
             nbgrader_jinja2_env=jinja_env,
-            nbgrader_bad_setup=nbgrader_bad_setup
+            nbgrader_bad_setup=nbgrader_bad_setup,
+            initial_config=self.config
         )
 
         webapp.settings.update(tornado_settings)

nbgrader/server_extensions/formgrader/handlers.py

@@ -1,26 +1,62 @@
 import os
 import re
 import sys
+import json
 
 from tornado import web
+from jupyter_core.paths import jupyter_config_dir
+from traitlets.config.loader import Config
 
 from .base import BaseHandler, check_xsrf, check_notebook_dir
 from ...api import MissingEntry
 
 
+class FormgraderHandler(BaseHandler):
+    @web.authenticated
+    @check_xsrf
+    @check_notebook_dir
+    def get(self):
+        formgrader = self.settings['nbgrader_formgrader']
+        path = self.get_argument('path', '')
+        if path:
+            path = os.path.abspath(path)
+            formgrader.load_cwd_config = False
+            formgrader.config = Config()
+            formgrader.config_dir = path
+            formgrader.initialize([], root=path)
+        else:
+            if formgrader.config != self.settings['initial_config']:
+                formgrader.config = self.settings['initial_config']
+                formgrader.config_dir = jupyter_config_dir()
+                formgrader.initialize([])
+            formgrader.load_cwd_config = True
+        self.redirect(f"{self.base_url}/formgrader/manage_assignments")
+
+
 class ManageAssignmentsHandler(BaseHandler):
     @web.authenticated
     @check_xsrf
     @check_notebook_dir
     def get(self):
+        formgrader = self.settings['nbgrader_formgrader']
+        current_config = {}
+        if formgrader.debug:
+            try:
+                current_config = json.dumps(formgrader.config, indent=2)
+            except TypeError:
+                current_config = formgrader.config
+                self.log.warn("Formgrader config is not serializable")
+
+        api = self.api
         html = self.render(
             "manage_assignments.tpl",
             url_prefix=self.url_prefix,
             base_url=self.base_url,
             windows=(sys.prefix == 'win32'),
-            course_id=self.api.course_id,
-            exchange=self.api.exchange_root,
-            exchange_missing=self.api.exchange_missing)
+            course_id=api.course_id,
+            exchange=api.exchange_root,
+            exchange_missing=api.exchange_missing,
+            current_config= current_config)
         self.write(html)
 
 
@@ -282,7 +318,7 @@ def prepare(self):
 _navigation_regex = r"(?P<action>next_incorrect|prev_incorrect|next|prev)"
 
 default_handlers = [
-    (r"/formgrader/?", ManageAssignmentsHandler),
+    (r"/formgrader/?", FormgraderHandler),
     (r"/formgrader/manage_assignments/?", ManageAssignmentsHandler),
     (r"/formgrader/manage_submissions/([^/]+)/?", ManageSubmissionsHandler),
 

nbgrader/server_extensions/formgrader/templates/manage_assignments.tpl

@@ -55,6 +55,22 @@ Manage Assignments
     </div>
   </div>
 </div>
+{% if current_config %}
+<div class="panel-group" id="config" role="tablist" aria-multiselectable="true">
+  <div class="panel panel-default">
+    <div class="panel-heading" role="tab" id="headingConfig">
+      <h4 class="panel-title">
+        <a class="collapsed" role="button" data-toggle="collapse" data-parent="#accordion" href="#collapseConfig" aria-expanded="false" aria-controls="collapseConfig">
+          Current configuration (click to expand)
+        </a>
+      </h4>
+    </div>
+    <div id="collapseConfig" class="panel-collapse collapse" role="tabpanel" aria-labelledby="headingConfig">
+      <pre class="panel-body">{{ current_config }}</pre>
+    </div>
+  </div>
+</div>
+{% endif %}
 {% if windows %}
 <div class="alert alert-warning" id="warning-windows">
 Windows operating system detected. Please note that the "release" and "collect"