Add Blueprint level cli command registration

Implements #1357.
Adds ability to register click cli commands onto blueprint.

flask/app.py

@@ -600,13 +600,9 @@ class Flask(_PackageBoundObject):
                 view_func=self.send_static_file,
             )
 
-        #: The click command line context for this application.  Commands
-        #: registered here show up in the :command:`flask` command once the
-        #: application has been discovered.  The default commands are
-        #: provided by Flask itself and can be overridden.
-        #:
-        #: This is an instance of a :class:`click.Group` object.
-        self.cli = cli.AppGroup(self.name)
+        # Set the name of the Click group in case someone wants to add
+        # the app's commands to another CLI tool.
+        self.cli.name = self.name
 
     @locked_cached_property
     def name(self):

flask/blueprints.py

@@ -13,6 +13,9 @@ from functools import update_wrapper
 
 from .helpers import _PackageBoundObject, _endpoint_from_view_func
 
+# a singleton sentinel value for parameter defaults
+_sentinel = object()
+
 
 class BlueprintSetupState(object):
     """Temporary holder object for registering a blueprint with the
@@ -90,6 +93,11 @@ class Blueprint(_PackageBoundObject):
     or other things on the main application.  See :ref:`blueprints` for more
     information.
 
+    .. versionchanged:: 1.1.0
+        Blueprints have a ``cli`` group to register nested CLI commands.
+        The ``cli_group`` parameter controls the name of the group under
+        the ``flask`` command.
+
     .. versionadded:: 0.7
     """
 
@@ -129,6 +137,7 @@ class Blueprint(_PackageBoundObject):
         subdomain=None,
         url_defaults=None,
         root_path=None,
+        cli_group=_sentinel,
     ):
         _PackageBoundObject.__init__(
             self, import_name, template_folder, root_path=root_path
@@ -142,6 +151,7 @@ class Blueprint(_PackageBoundObject):
         if url_defaults is None:
             url_defaults = {}
         self.url_values_defaults = url_defaults
+        self.cli_group = cli_group
 
     def record(self, func):
         """Registers a function that is called when the blueprint is
@@ -206,6 +216,17 @@ class Blueprint(_PackageBoundObject):
         for deferred in self.deferred_functions:
             deferred(state)
 
+        cli_resolved_group = options.get("cli_group", self.cli_group)
+
+        if cli_resolved_group is None:
+            app.cli.commands.update(self.cli.commands)
+        elif cli_resolved_group is _sentinel:
+            self.cli.name = self.name
+            app.cli.add_command(self.cli)
+        else:
+            self.cli.name = cli_resolved_group
+            app.cli.add_command(self.cli)
+
     def route(self, rule, **options):
         """Like :meth:`Flask.route` but for a blueprint.  The endpoint for the
         :func:`url_for` function is prefixed with the name of the blueprint.

flask/helpers.py

@@ -942,6 +942,15 @@ class _PackageBoundObject(object):
         self._static_folder = None
         self._static_url_path = None
 
+        # circular import
+        from .cli import AppGroup
+
+        #: The Click command group for registration of CLI commands
+        #: on the application and associated blueprints. These commands
+        #: are accessible via the :command:`flask` command once the
+        #: application has been discovered and blueprints registered.
+        self.cli = AppGroup()
+
     def _get_static_folder(self):
         if self._static_folder is not None:
             return os.path.join(self.root_path, self._static_folder)