Add download feature for file batches.

tailbone/views/batch.py

@@ -35,7 +35,9 @@ import logging
 
 import formalchemy
 from pyramid.renderers import render_to_response
+from pyramid.response import FileResponse
 from pyramid.httpexceptions import HTTPFound, HTTPNotFound
+from webhelpers.html.tags import link_to
 
 from rattail.db import model
 from rattail.db import Session as RatSession
@@ -517,6 +519,28 @@ class BatchCrud(BaseCrud):
         return HTTPFound(location=self.view_url(batch.uuid))
 
 
+class DownloadLinkRenderer(formalchemy.FieldRenderer):
+    """
+    Field renderer for batch filenames, shows a link to download the file.
+    """
+
+    def __init__(self, route_prefix):
+        self.route_prefix = route_prefix
+
+    def __call__(self, field):
+        super(DownloadLinkRenderer, self).__init__(field)
+        return self
+
+    def render_readonly(self, **kwargs):
+        filename = self.value
+        if not filename:
+            return ''
+        batch = self.field.parent.model
+        return link_to(filename, self.request.route_url(
+                '{0}.download'.format(self.route_prefix),
+                uuid=batch.uuid))
+
+
 class FileBatchCrud(BatchCrud):
     """
     Base CRUD view for batches which involve a file upload as the first step.
@@ -545,6 +569,7 @@ class FileBatchCrud(BatchCrud):
         fs.executed_by.set(label="Executed by", renderer=UserFieldRenderer)
         fs.append(formalchemy.Field('data_file'))
         fs.data_file.set(renderer=formalchemy.fields.FileFieldRenderer)
+        fs.filename.set(renderer=DownloadLinkRenderer(self.route_prefix))
         self.configure_fieldset(fs)
         if self.creating:
             del fs.created
@@ -649,6 +674,20 @@ class FileBatchCrud(BatchCrud):
         batch.delete_data(self.request.rattail_config)
         del batch.data_rows[:]
 
+    def download(self):
+        """
+        View for downloading the data file associated with a batch.
+        """
+        batch = self.current_batch()
+        if not batch:
+            return HTTPNotFound()
+        config = self.request.rattail_config
+        path = batch.filepath(config)
+        response = FileResponse(path, request=self.request)
+        response.headers[b'Content-Length'] = str(batch.filesize(config))
+        response.headers[b'Content-Disposition'] = b'attachment; filename={0}'.format(batch.filename)
+        return response
+
 
 class BatchRowGrid(BaseGrid):
     """
@@ -877,6 +916,12 @@ def defaults(config, batch_grid, batch_crud, row_grid, row_crud, url_prefix,
     config.add_view(batch_crud, attr='execute', route_name='{0}.execute'.format(route_prefix),
                     permission='{0}.execute'.format(permission_prefix))
 
+    # Download batch data file
+    if hasattr(batch_crud, 'download'):
+        config.add_route('{0}.download'.format(route_prefix), '{0}{{uuid}}/download'.format(url_prefix))
+        config.add_view(batch_crud, attr='download', route_name='{0}.download'.format(route_prefix),
+                        permission='{0}.download'.format(permission_prefix))
+
     # Delete batch
     config.add_route('{0}.delete'.format(route_prefix), '{0}{{uuid}}/delete'.format(url_prefix))
     config.add_view(batch_crud, attr='delete', route_name='{0}.delete'.format(route_prefix),
@@ -891,7 +936,7 @@ def defaults(config, batch_grid, batch_crud, row_grid, row_crud, url_prefix,
     # Bulk delete batch rows
     config.add_route('{0}.rows.bulk_delete'.format(route_prefix), '{0}{{uuid}}/rows/delete'.format(url_prefix))
     config.add_view(row_grid, attr='bulk_delete', route_name='{0}.rows.bulk_delete'.format(route_prefix),
-                    permission='{0}.delete'.format(permission_prefix))
+                    permission='{0}.edit'.format(permission_prefix))
 
     # Delete batch row
     config.add_route('{0}.rows.delete'.format(route_prefix), '{0}delete-row/{{uuid}}'.format(url_prefix))