Add new "master" API view class; refactor products and batches to use it

tailbone/api/master2.py

@@ -0,0 +1,141 @@
+# -*- coding: utf-8; -*-
+################################################################################
+#
+#  Rattail -- Retail Software Framework
+#  Copyright © 2010-2020 Lance Edgar
+#
+#  This file is part of Rattail.
+#
+#  Rattail is free software: you can redistribute it and/or modify it under the
+#  terms of the GNU General Public License as published by the Free Software
+#  Foundation, either version 3 of the License, or (at your option) any later
+#  version.
+#
+#  Rattail is distributed in the hope that it will be useful, but WITHOUT ANY
+#  WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+#  FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
+#  details.
+#
+#  You should have received a copy of the GNU General Public License along with
+#  Rattail.  If not, see <http://www.gnu.org/licenses/>.
+#
+################################################################################
+"""
+Tailbone Web API - Master View (v2)
+"""
+
+from __future__ import unicode_literals, absolute_import
+
+from cornice import resource, Service
+
+from tailbone.api import APIMasterView
+
+
+class APIMasterView2(APIMasterView):
+    """
+    Base class for data model REST API views.
+    """
+    listable = True
+    creatable = True
+    viewable = True
+    editable = True
+    deletable = True
+    supports_autocomplete = False
+
+    @classmethod
+    def establish_method(cls, method_name):
+        """
+        Establish the given HTTP method for this Cornice Resource.
+
+        Cornice will auto-register any class methods for a resource, if they
+        are named according to what it expects (i.e. 'get', 'collection_get'
+        etc.).  Tailbone API tries to make things automagical for the sake of
+        e.g. Poser logic, but in this case if we predefine all of these methods
+        and then some subclass view wants to *not* allow one, it's not clear
+        how to "undefine" it per se.  Or at least, the more straightforward
+        thing (I think) is to not define such a method in the first place, if
+        it was not wanted.
+
+        Enter ``establish_method()``, which is what finally "defines" each
+        resource method according to what the subclass has declared via its
+        various attributes (:attr:`creatable`, :attr:`deletable` etc.).
+
+        Note that you will not likely have any need to use this
+        ``establish_method()`` yourself!  But we describe its purpose here, for
+        clarity.
+        """
+        def method(self):
+            internal_method = getattr(self, '_{}'.format(method_name))
+            return internal_method()
+
+        setattr(cls, method_name, method)
+
+    def _delete(self):
+        """
+        View to handle DELETE action for an existing record/object.
+        """
+        obj = self.get_object()
+        self.delete_object(obj)
+
+    def delete_object(self, obj):
+        """
+        Delete the object, or mark it as deleted, or whatever you need to do.
+        """
+        # flush immediately to force any pending integrity errors etc.
+        self.Session.delete(obj)
+        self.Session.flush()
+
+    @classmethod
+    def defaults(cls, config):
+        cls._defaults(config)
+
+    @classmethod
+    def _defaults(cls, config):
+        route_prefix = cls.get_route_prefix()
+        permission_prefix = cls.get_permission_prefix()
+        collection_url_prefix = cls.get_collection_url_prefix()
+        object_url_prefix = cls.get_object_url_prefix()
+
+        # first, the primary resource API
+
+        # list/search
+        if cls.listable:
+            cls.establish_method('collection_get')
+            resource.add_view(cls.collection_get, permission='{}.list'.format(permission_prefix))
+
+        # create
+        if cls.creatable:
+            cls.establish_method('collection_post')
+            resource.add_view(cls.collection_post, permission='{}.create'.format(permission_prefix))
+
+        # view
+        if cls.viewable:
+            cls.establish_method('get')
+            resource.add_view(cls.get, permission='{}.view'.format(permission_prefix))
+
+        # edit
+        if cls.editable:
+            cls.establish_method('post')
+            resource.add_view(cls.post, permission='{}.edit'.format(permission_prefix))
+
+        # delete
+        if cls.deletable:
+            cls.establish_method('delete')
+            resource.add_view(cls.delete, permission='{}.delete'.format(permission_prefix))
+
+        # register primary resource API via cornice
+        object_resource = resource.add_resource(
+            cls,
+            collection_path=collection_url_prefix,
+            # TODO: probably should allow for other (composite?) key fields
+            path='{}/{{uuid}}'.format(object_url_prefix))
+        config.add_cornice_resource(object_resource)
+
+        # now for some more "custom" things, which are still somewhat generic
+
+        # autocomplete
+        if cls.supports_autocomplete:
+            autocomplete = Service(name='{}.autocomplete'.format(route_prefix),
+                                   path='{}/autocomplete'.format(collection_url_prefix))
+            autocomplete.add_view('GET', 'autocomplete', klass=cls)
+            config.add_cornice_service(autocomplete)