Add progress support when deleting a batch

b/c we must delete all rows individually, and some batches can be
several thousand rows each

tailbone/views/batch/core.py

@@ -82,6 +82,7 @@ class BatchMasterView(MasterView):
     results_executable = False
     has_worksheet = False
     has_worksheet_file = False
+    delete_requires_progress = True
 
     input_file_template_config_section = 'rattail.batch'
 
@@ -742,8 +743,55 @@ class BatchMasterView(MasterView):
         """
         Delete all data (files etc.) for the batch.
         """
-        self.handler.do_delete(batch)
-        super(BatchMasterView, self).delete_instance(batch)
+        app = self.get_rattail_app()
+        session = app.get_session(batch)
+        self.batch_handler.do_delete(batch)
+        session.flush()
+
+    def delete_instance_with_progress(self, batch):
+        """
+        Delete all data (files etc.) for the batch.
+        """
+        return self.handler_action(batch, 'delete')
+
+    def delete_thread(self, key, user_uuid, progress, **kwargs):
+        """
+        Thread target for deleting a batch with progress indicator.
+        """
+        app = self.get_rattail_app()
+        model = self.model
+        # nb. must make new session, separate from main thread
+        session = app.make_session()
+        batch = self.get_instance_for_key(key, session)
+        batch_str = six.text_type(batch)
+
+        try:
+            # try to delete batch
+            self.handler.do_delete(batch, progress=progress, **kwargs)
+
+        except Exception as error:
+            # error; log that and rollback
+            log.exception("delete failed for batch: %s", batch)
+            session.rollback()
+            session.close()
+            if progress:
+                progress.session.load()
+                progress.session['error'] = True
+                progress.session['error_msg'] = "Batch deletion failed: {}".format(
+                    simple_error(error))
+                progress.session.save()
+
+        else:
+            # no error; finish up
+            session.commit()
+            session.close()
+            if progress:
+                progress.session.load()
+                progress.session['complete'] = True
+                progress.session['success_url'] = self.get_index_url()
+                progress.session['success_msg'] = "Batch has been deleted: {}".format(
+                    batch_str)
+                progress.session.save()
 
     def get_fallback_templates(self, template, **kwargs):
         return [

tailbone/views/master.py

@@ -100,6 +100,7 @@ class MasterView(View):
     viewable = True
     editable = True
     deletable = True
+    delete_requires_progress = False
     delete_confirm = 'full'
     bulk_deletable = False
     set_deletable = False
@@ -1590,10 +1591,13 @@ class MasterView(View):
             if isinstance(result, httpexceptions.HTTPException):
                 return result
 
-            self.delete_instance(instance)
-            self.request.session.flash("{} has been deleted: {}".format(
-                self.get_model_title(), instance_title))
-            return self.redirect(self.get_after_delete_url(instance))
+            if self.delete_requires_progress:
+                return self.delete_instance_with_progress(instance)
+            else:
+                self.delete_instance(instance)
+                self.request.session.flash("{} has been deleted: {}".format(
+                    self.get_model_title(), instance_title))
+                return self.redirect(self.get_after_delete_url(instance))
 
         form.readonly = True
         return self.render_to_response('delete', {