Add order_by to list user admin API (#9691)

docs/admin_api/user_admin_api.rst

@@ -111,35 +111,16 @@ List Accounts
 =============
 
 This API returns all local user accounts.
+By default, the response is ordered by ascending user ID.
 
-The api is::
+The API is::
 
     GET /_synapse/admin/v2/users?from=0&limit=10&guests=false
 
 To use it, you will need to authenticate by providing an ``access_token`` for a
 server admin: see `README.rst <README.rst>`_.
 
-The parameter ``from`` is optional but used for pagination, denoting the
-offset in the returned results. This should be treated as an opaque value and
-not explicitly set to anything other than the return value of ``next_token``
-from a previous call.
-
-The parameter ``limit`` is optional but is used for pagination, denoting the
-maximum number of items to return in this call. Defaults to ``100``.
-
-The parameter ``user_id`` is optional and filters to only return users with user IDs
-that contain this value. This parameter is ignored when using the ``name`` parameter.
-
-The parameter ``name`` is optional and filters to only return users with user ID localparts
-**or** displaynames that contain this value.
-
-The parameter ``guests`` is optional and if ``false`` will **exclude** guest users.
-Defaults to ``true`` to include guest users.
-
-The parameter ``deactivated`` is optional and if ``true`` will **include** deactivated users.
-Defaults to ``false`` to exclude deactivated users.
-
-A JSON body is returned with the following shape:
+A response body like the following is returned:
 
 .. code:: json
 
@@ -175,6 +156,66 @@ with ``from`` set to the value of ``next_token``. This will return a new page.
 If the endpoint does not return a ``next_token`` then there are no more users
 to paginate through.
 
+**Parameters**
+
+The following parameters should be set in the URL:
+
+- ``user_id`` - Is optional and filters to only return users with user IDs
+  that contain this value. This parameter is ignored when using the ``name`` parameter.
+- ``name`` - Is optional and filters to only return users with user ID localparts
+  **or** displaynames that contain this value.
+- ``guests`` - string representing a bool - Is optional and if ``false`` will **exclude** guest users.
+  Defaults to ``true`` to include guest users.
+- ``deactivated`` - string representing a bool - Is optional and if ``true`` will **include** deactivated users.
+  Defaults to ``false`` to exclude deactivated users.
+- ``limit`` - string representing a positive integer - Is optional but is used for pagination,
+  denoting the maximum number of items to return in this call. Defaults to ``100``.
+- ``from`` - string representing a positive integer - Is optional but used for pagination,
+  denoting the offset in the returned results. This should be treated as an opaque value and
+  not explicitly set to anything other than the return value of ``next_token`` from a previous call.
+  Defaults to ``0``.
+- ``order_by`` - The method by which to sort the returned list of users.
+  If the ordered field has duplicates, the second order is always by ascending ``name``,
+  which guarantees a stable ordering. Valid values are:
+
+  - ``name`` - Users are ordered alphabetically by ``name``. This is the default.
+  - ``is_guest`` - Users are ordered by ``is_guest`` status.
+  - ``admin`` - Users are ordered by ``admin`` status.
+  - ``user_type`` - Users are ordered alphabetically by ``user_type``.
+  - ``deactivated`` - Users are ordered by ``deactivated`` status.
+  - ``shadow_banned`` - Users are ordered by ``shadow_banned`` status.
+  - ``displayname`` - Users are ordered alphabetically by ``displayname``.
+  - ``avatar_url`` - Users are ordered alphabetically by avatar URL.
+
+- ``dir`` - Direction of media order. Either ``f`` for forwards or ``b`` for backwards.
+  Setting this value to ``b`` will reverse the above sort order. Defaults to ``f``.
+
+Caution. The database only has indexes on the columns ``name`` and ``created_ts``.
+This means that if a different sort order is used (``is_guest``, ``admin``,
+``user_type``, ``deactivated``, ``shadow_banned``, ``avatar_url`` or ``displayname``),
+this can cause a large load on the database, especially for large environments.
+
+**Response**
+
+The following fields are returned in the JSON response body:
+
+- ``users`` - An array of objects, each containing information about an user.
+  User objects contain the following fields:
+
+  - ``name`` - string - Fully-qualified user ID (ex. `@user:server.com`).
+  - ``is_guest`` - bool - Status if that user is a guest account.
+  - ``admin`` - bool - Status if that user is a server administrator.
+  - ``user_type`` - string - Type of the user. Normal users are type ``None``.
+    This allows user type specific behaviour. There are also types ``support`` and ``bot``. 
+  - ``deactivated`` - bool - Status if that user has been marked as deactivated.
+  - ``shadow_banned`` - bool - Status if that user has been marked as shadow banned.
+  - ``displayname`` - string - The user's display name if they have set one.
+  - ``avatar_url`` - string -  The user's avatar URL if they have set one.
+
+- ``next_token``: string representing a positive integer - Indication for pagination. See above.
+- ``total`` - integer - Total number of media.
+
+
 Query current sessions for a user
 =================================