Add progress for generating "results as CSV" file to download

tailbone/templates/master/index.mako

@@ -296,6 +296,11 @@
   <script type="text/javascript">
 
     ## TODO: stop checking for buefy here once we only have the one session.pop()
+    % if use_buefy and request.session.pop('{}.results_csv.generated'.format(route_prefix), False):
+        ThisPage.mounted = function() {
+            location.href = '${url('{}.results_csv_download'.format(route_prefix))}';
+        }
+    % endif
     % if use_buefy and request.session.pop('{}.results_xlsx.generated'.format(route_prefix), False):
         ThisPage.mounted = function() {
             location.href = '${url('{}.results_xlsx_download'.format(route_prefix))}';
@@ -462,6 +467,13 @@
     % endif
 
     ## TODO: can stop checking for buefy above once this legacy chunk is gone
+    % if request.session.pop('{}.results_csv.generated'.format(route_prefix), False):
+        <script type="text/javascript">
+          $(function() {
+              location.href = '${url('{}.results_csv_download'.format(route_prefix))}';
+          });
+        </script>
+    % endif
     % if request.session.pop('{}.results_xlsx.generated'.format(route_prefix), False):
         <script type="text/javascript">
           $(function() {

tailbone/views/master.py

@@ -2677,27 +2677,94 @@ class MasterView(View):
 
     def results_csv(self):
         """
-        Download current list results as CSV
+        Download current list results as CSV.
         """
         results = self.get_effective_data()
+
+        # start thread to actually do work / generate progress data
+        route_prefix = self.get_route_prefix()
+        key = '{}.results_csv'.format(route_prefix)
+        progress = self.make_progress(key)
+        thread = Thread(target=self.results_csv_thread,
+                        args=(results, self.request.user.uuid, progress))
+        thread.start()
+
+        # send user to progress page
+        return self.render_progress(progress, {
+            'cancel_url': self.get_index_url(),
+            'cancel_msg': "CSV download was canceled.",
+        })
+
+    def results_csv_session(self):
+        return RattailSession()
+
+    def results_csv_thread(self, results, user_uuid, progress):
+        """
+        Thread target, responsible for actually generating the CSV file which
+        is to be presented for download.
+        """
+        route_prefix = self.get_route_prefix()
+        session = self.results_csv_session()
+        try:
+
+            # create folder(s) for output; make sure file doesn't exist
+            path = os.path.join(self.rattail_config.datadir(), 'downloads',
+                                'results-csv', route_prefix,
+                                user_uuid[:2], user_uuid[2:])
+            if not os.path.exists(path):
+                os.makedirs(path)
+            path = os.path.join(path, '{}.csv'.format(route_prefix))
+            if os.path.exists(path):
+                os.remove(path)
+
+            results = results.with_session(session).all()
             fields = self.get_csv_fields()
-        data = six.StringIO()
+
-        writer = UnicodeDictWriter(data, fields)
+            csv_file = open(path, 'wt')
+            writer = UnicodeDictWriter(csv_file, fields)
             writer.writeheader()
-        for obj in results:
+
+            def write(obj, i):
                 writer.writerow(self.get_csv_row(obj, fields))
-        response = self.request.response
+
-        if six.PY3:
+            self.progress_loop(write, results, progress,
-            response.text = data.getvalue()
+                               message="Collecting data for CSV")
-            response.content_type = 'text/csv'
+            csv_file.close()
-            response.content_disposition = 'attachment; filename={}.csv'.format(self.get_grid_key())
+            session.commit()
-        else:
+
-            response.body = data.getvalue()
+        except Exception as error:
-            response.content_type = b'text/csv'
+            msg = "generating CSV file for download failed!"
-            response.content_disposition = b'attachment; filename={}.csv'.format(self.get_grid_key())
+            log.warning(msg, exc_info=True)
-        data.close()
+            session.rollback()
-        response.content_length = len(response.body)
+            session.close()
-        return response
+            if progress:
+                progress.session.load()
+                progress.session['error'] = True
+                progress.session['error_msg'] = "{}: {}".format(
+                    msg, simple_error(error))
+                progress.session.save()
+            return
+
+        finally:
+            session.close()
+
+        if progress:
+            progress.session.load()
+            progress.session['complete'] = True
+            progress.session['success_url'] = self.get_index_url()
+            progress.session['extra_session_bits'] = {
+                '{}.results_csv.generated'.format(route_prefix): True,
+            }
+            progress.session.save()
+
+    def results_csv_download(self):
+        route_prefix = self.get_route_prefix()
+        user_uuid = self.request.user.uuid
+        path = os.path.join(self.rattail_config.datadir(), 'downloads',
+                            'results-csv', route_prefix,
+                            user_uuid[:2], user_uuid[2:],
+                            '{}.csv'.format(route_prefix))
+        return self.file_response(path)
 
     def results_xlsx(self):
         """
@@ -3740,6 +3807,9 @@ class MasterView(View):
                 config.add_route('{}.results_csv'.format(route_prefix), '{}/csv'.format(url_prefix))
                 config.add_view(cls, attr='results_csv', route_name='{}.results_csv'.format(route_prefix),
                                 permission='{}.results_csv'.format(permission_prefix))
+                config.add_route('{}.results_csv_download'.format(route_prefix), '{}/csv/download'.format(url_prefix))
+                config.add_view(cls, attr='results_csv_download', route_name='{}.results_csv_download'.format(route_prefix),
+                                permission='{}.results_csv'.format(permission_prefix))
 
             if cls.results_downloadable_xlsx:
                 config.add_tailbone_permission(permission_prefix, '{}.results_xlsx'.format(permission_prefix),