Optional argument to get only the schema names (#385)

* Adds an optional argument to get only the schemas names

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* Adds the federated extensions too, and avoid duplicating the file search by using the same function as previously

* Adds a test on fetching the schema IDs

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* Change the argument 'names_only' to 'ids_only' for consistency

* Updating doc string

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

Author: brichet

jupyterlab_server/settings_handler.py

@@ -26,12 +26,25 @@ def initialize(
 
     @web.authenticated
     def get(self, schema_name=""):
-        """Get setting(s)"""
+        """
+        Get setting(s)
+
+        Parameters
+        ----------
+        schema_name: str
+            The id of a unique schema to send, added to the URL
+
+        ## NOTES:
+            An optional argument `ids_only=true` can be provided in the URL to get only the
+            ids of the schemas instead of the content.
+        """
         # Need to be update here as translator locale is not change when a new locale is put
         # from frontend
         locale = self.get_current_locale()
         translator.set_locale(locale)
 
+        ids_only = self.get_argument('ids_only', '') == 'true'
+
         result, warnings = get_settings(
             self.app_settings_dir,
             self.schemas_dir,
@@ -40,6 +53,7 @@ def get(self, schema_name=""):
             schema_name=schema_name,
             overrides=self.overrides,
             translator=translator.translate_schema,
+            ids_only=ids_only,
         )
 
         # Print all warnings.

jupyterlab_server/settings_utils.py

@@ -129,11 +129,13 @@ def _list_settings(
     extension=".json",
     labextensions_path=None,
     translator=None,
+    ids_only=False,
 ):
     """
     Returns a tuple containing:
      - the list of plugins, schemas, and their settings,
-       respecting any defaults that may have been overridden.
+       respecting any defaults that may have been overridden if `ids_only=False`,
+       otherwise a list of dict containing only the ids of plugins.
      - the list of warnings that were generated when
        validating the user overrides against the schemas.
     """
@@ -159,16 +161,20 @@ def _list_settings(
         ).replace(
             "\\", "/"
         )  # Normalize slashes.
-        schema, version = _get_schema(schemas_dir, schema_name, overrides, None)
-        if translator is not None:
-            schema = translator(schema)
-        user_settings = _get_user_settings(settings_dir, schema_name, schema)
 
-        if user_settings["warning"]:
-            warnings.append(user_settings.pop("warning"))
+        if ids_only:
+            settings[_id] = dict(id=_id)
+        else:
+            schema, version = _get_schema(schemas_dir, schema_name, overrides, None)
+            if translator is not None:
+                schema = translator(schema)
+            user_settings = _get_user_settings(settings_dir, schema_name, schema)
+
+            if user_settings["warning"]:
+                warnings.append(user_settings.pop("warning"))
 
-        # Add the plugin to the list of settings.
-        settings[_id] = dict(id=_id, schema=schema, version=version, **user_settings)
+            # Add the plugin to the list of settings.
+            settings[_id] = dict(id=_id, schema=schema, version=version, **user_settings)
 
     if labextensions_path is not None:
         schema_paths = []
@@ -195,16 +201,21 @@ def _list_settings(
             if _id in federated_settings:
                 continue
 
-            schema, version = _get_schema(
-                schemas_dir, schema_name, overrides, labextensions_path=labextensions_path
-            )
-            user_settings = _get_user_settings(settings_dir, schema_name, schema)
+            if ids_only:
+                federated_settings[_id] = dict(id=_id)
+            else:
+                schema, version = _get_schema(
+                    schemas_dir, schema_name, overrides, labextensions_path=labextensions_path
+                )
+                user_settings = _get_user_settings(settings_dir, schema_name, schema)
 
-            if user_settings["warning"]:
-                warnings.append(user_settings.pop("warning"))
+                if user_settings["warning"]:
+                    warnings.append(user_settings.pop("warning"))
 
-            # Add the plugin to the list of settings.
-            federated_settings[_id] = dict(id=_id, schema=schema, version=version, **user_settings)
+                # Add the plugin to the list of settings.
+                federated_settings[_id] = dict(
+                    id=_id, schema=schema, version=version, **user_settings
+                )
 
     settings.update(federated_settings)
     settings_list = [settings[key] for key in sorted(settings.keys(), reverse=True)]
@@ -317,6 +328,7 @@ def get_settings(
     overrides=None,
     labextensions_path=None,
     translator=None,
+    ids_only=False,
 ):
     """
     Get settings.
@@ -343,9 +355,10 @@ def get_settings(
     -------
     tuple
         The first item is a dictionary with a list of setting if no `schema_name`
-        was provided, otherwise it is a dictionary with id, raw, scheme, settings
-        and version keys. The second item is a list of warnings. Warnings will
-        either be a list of i) strings with the warning messages or ii) `None`.
+        was provided (only the ids if `ids_only=True`), otherwise it is a dictionary
+        with id, raw, scheme, settings and version keys.
+        The second item is a list of warnings. Warnings will either be a list of
+        i) strings with the warning messages or ii) `None`.
     """
     result = {}
     warnings = []
@@ -367,6 +380,7 @@ def get_settings(
             overrides,
             labextensions_path=labextensions_path,
             translator=translator,
+            ids_only=ids_only,
         )
         result = {
             "settings": settings_list,

tests/test_settings_api.py

@@ -104,6 +104,30 @@ async def test_listing(jp_fetch, labserverapp):
     assert {None} == set(last_modifieds + createds)
 
 
+async def test_listing_ids(jp_fetch, labserverapp):
+    ids = [
+        "@jupyterlab/apputils-extension:themes",
+        "@jupyterlab/apputils-extension-federated:themes",
+        "@jupyterlab/codemirror-extension:commands",
+        "@jupyterlab/codemirror-extension-federated:commands",
+        "@jupyterlab/shortcuts-extension:plugin",
+        "@jupyterlab/translation-extension:plugin",
+        "@jupyterlab/unicode-extension:plugin",
+    ]
+    r = await jp_fetch("lab", "api", "settings/", params={"ids_only": "true"})
+    validate_request(r)
+    res = r.body.decode()
+    response = json.loads(res)
+    response_ids = [item["id"] for item in response["settings"]]
+    # Checks the IDs list is correct
+    assert set(response_ids) == set(ids)
+
+    # Checks there is only the 'id' key in each item
+    assert all(
+        [(len(item.keys()) == 1 and list(item.keys())[0] == 'id') for item in response["settings"]]
+    )
+
+
 async def test_patch(jp_fetch, labserverapp):
     id = "@jupyterlab/shortcuts-extension:plugin"