Add support for "delete set" feature for main object index view

aka. "delete selected objects"

tailbone/views/master.py

@@ -82,6 +82,7 @@ class MasterView(View):
     editable = True
     deletable = True
     bulk_deletable = False
+    set_deletable = False
     populatable = False
     mergeable = False
     downloadable = False
@@ -326,6 +327,14 @@ class MasterView(View):
         Return a dictionary of kwargs to be passed to the factory when creating
         new grid instances.
         """
+        permission_prefix = self.get_permission_prefix()
+
+        checkboxes = self.checkboxes
+        if not checkboxes and self.mergeable and self.request.has_perm('{}.merge'.format(permission_prefix)):
+            checkboxes = True
+        if not checkboxes and self.set_deletable and self.request.has_perm('{}.delete_set'.format(permission_prefix)):
+            checkboxes = True
+
         defaults = {
             'model_class': getattr(self, 'model_class', None),
             'width': 'full',
@@ -335,8 +344,7 @@ class MasterView(View):
             'pageable': self.pageable,
             'extra_row_class': self.grid_extra_class,
             'url': lambda obj: self.get_action_url('view', obj),
-            'checkboxes': self.checkboxes or (
-                self.mergeable and self.request.has_perm('{}.merge'.format(self.get_permission_prefix()))),
+            'checkboxes': checkboxes,
             'checked': self.checked,
         }
         if 'main_actions' not in kwargs and 'more_actions' not in kwargs:
@@ -1569,7 +1577,6 @@ class MasterView(View):
         """
         Delete all records matching the current grid query
         """
-        if self.request.method == 'POST':
         objects = self.get_effective_data()
         key = '{}.bulk_delete'.format(self.model_class.__tablename__)
         progress = SessionProgress(self.request, key)
@@ -1579,9 +1586,6 @@ class MasterView(View):
             'cancel_url': self.get_index_url(),
             'cancel_msg': "Bulk deletion was canceled",
         })
-        else:
-            self.request.session.flash("Sorry, you must POST to do a bulk delete operation")
-        return self.redirect(self.get_index_url())
 
     def bulk_delete_objects(self, session, objects, progress=None):
 
@@ -1626,6 +1630,26 @@ class MasterView(View):
                 progress.session['success_url'] = self.get_index_url()
                 progress.session.save()
 
+    def delete_set(self):
+        """
+        View which can delete a specific set of records.
+        """
+        # TODO: should have a cleaner way to parse object uuids?
+        uuids = self.request.POST.get('uuids')
+        if uuids:
+            uuids = uuids.split(',')
+            # TODO: probably need to allow override of fetcher callable
+            fetcher = lambda uuid: self.Session.query(self.model_class).get(uuid)
+            deleted = 0
+            for uuid in uuids:
+                obj = fetcher(uuid)
+                if obj:
+                    self.delete_instance(obj)
+                    deleted += 1
+            model_title_plural = self.get_model_title_plural()
+            self.request.session.flash("Deleted {} {}".format(deleted, model_title_plural))
+        return self.redirect(self.get_index_url())
+
     def oneoff_import(self, importer, host_object=None):
         """
         Basic helper method, to do a one-off import (or export, depending on
@@ -3057,12 +3081,22 @@ class MasterView(View):
 
         # bulk delete
         if cls.bulk_deletable:
-            config.add_route('{}.bulk_delete'.format(route_prefix), '{}/bulk-delete'.format(url_prefix))
+            config.add_route('{}.bulk_delete'.format(route_prefix), '{}/bulk-delete'.format(url_prefix),
+                             request_method='POST')
             config.add_view(cls, attr='bulk_delete', route_name='{}.bulk_delete'.format(route_prefix),
                             permission='{}.bulk_delete'.format(permission_prefix))
             config.add_tailbone_permission(permission_prefix, '{}.bulk_delete'.format(permission_prefix),
                                            "Bulk delete {}".format(model_title_plural))
 
+        # delete set
+        if cls.set_deletable:
+            config.add_tailbone_permission(permission_prefix, '{}.delete_set'.format(permission_prefix),
+                                           "Delete set (selection) of {}".format(model_title_plural))
+            config.add_route('{}.delete_set'.format(route_prefix), '{}/delete-set'.format(url_prefix),
+                             request_method='POST')
+            config.add_view(cls, attr='delete_set', route_name='{}.delete_set'.format(route_prefix),
+                            permission='{}.delete_set'.format(permission_prefix))
+
         # merge
         if cls.mergeable:
             config.add_route('{}.merge'.format(route_prefix), '{}/merge'.format(url_prefix))