Add ability to download batch row data as CSV.

tailbone/templates/batch/crud.mako

@@ -42,21 +42,25 @@
     </style>
 </%def>
 
+<%def name="context_menu_items()">
+  <li>${h.link_to("Back to {0}".format(batch_display_plural), url(route_prefix))}</li>
+  % if not batch.executed:
+      % if form.updating:
+          <li>${h.link_to("View this {0}".format(batch_display), url('{0}.view'.format(route_prefix), uuid=batch.uuid))}</li>
+      % endif
+      % if form.readonly and request.has_perm('{0}.edit'.format(permission_prefix)):
+          <li>${h.link_to("Edit this {0}".format(batch_display), url('{0}.edit'.format(route_prefix), uuid=batch.uuid))}</li>
+      % endif
+  % endif
+  % if request.has_perm('{0}.delete'.format(permission_prefix)):
+      <li>${h.link_to("Delete this {0}".format(batch_display), url('{0}.delete'.format(route_prefix), uuid=batch.uuid))}</li>
+  % endif
+</%def>
+
 <div class="form-wrapper">
 
   <ul class="context-menu">
-    <li>${h.link_to("Back to {0}".format(batch_display_plural), url(route_prefix))}</li>
-    % if not batch.executed:
-        % if form.updating:
-            <li>${h.link_to("View this {0}".format(batch_display), url('{0}.view'.format(route_prefix), uuid=batch.uuid))}</li>
-        % endif
-        % if form.readonly and request.has_perm('{0}.edit'.format(permission_prefix)):
-            <li>${h.link_to("Edit this {0}".format(batch_display), url('{0}.edit'.format(route_prefix), uuid=batch.uuid))}</li>
-        % endif
-    % endif
-    % if request.has_perm('{0}.delete'.format(permission_prefix)):
-        <li>${h.link_to("Delete this {0}".format(batch_display), url('{0}.delete'.format(route_prefix), uuid=batch.uuid))}</li>
-    % endif
+    ${self.context_menu_items()}
   </ul>
 
   ${form.render(form_id='batch-form', buttons=capture(buttons))|n}

tailbone/templates/batch/view.mako

@@ -13,6 +13,13 @@
   </script>
 </%def>
 
+<%def name="context_menu_items()">
+  ${parent.context_menu_items()}
+  % if request.has_perm('{0}.csv'.format(permission_prefix)):
+      <li>${h.link_to("Download this {0} as CSV".format(batch_display), url('{0}.csv'.format(route_prefix), uuid=batch.uuid))}</li>
+  % endif
+</%def>
+
 <%def name="buttons()">
     <div class="buttons">
       % if not form.readonly and batch.refreshable:

tailbone/views/batch.py

@@ -32,6 +32,9 @@ from __future__ import unicode_literals
 import os
 import datetime
 import logging
+from cStringIO import StringIO
+
+from sqlalchemy import orm
 
 import formalchemy
 from pyramid.renderers import render_to_response
@@ -42,6 +45,7 @@ from webhelpers.html.tags import link_to, HTML
 from rattail.db import model
 from rattail.db import Session as RatSession
 from rattail.threads import Thread
+from rattail.csvutil import UnicodeDictWriter
 
 from tailbone.db import Session
 from tailbone.views import SearchableAlchemyGridView, CrudView
@@ -366,6 +370,10 @@ class BatchCrud(BaseCrud):
     def batch_class(self):
         raise NotImplementedError
 
+    @property
+    def batch_row_class(self):
+        raise NotImplementedError
+
     @property
     def mapped_class(self):
         return self.batch_class
@@ -705,6 +713,48 @@ class BatchCrud(BaseCrud):
                 progress.session['success_url'] = self.view_url(batch.uuid)
                 progress.session.save()
         
+    def csv(self):
+        """
+        Download batch data as CSV.
+        """
+        batch = self.current_batch()
+        fields = self.get_csv_fields()
+        data = StringIO()
+        writer = UnicodeDictWriter(data, fields)
+        writer.writeheader()
+        for row in batch.data_rows:
+            if not row.removed:
+                writer.writerow(self.get_csv_row(row, fields))
+        response = self.request.response
+        response.text = data.getvalue().decode('utf_8')
+        data.close()
+        response.content_length = len(response.text)
+        response.content_type = b'text/csv'
+        response.content_disposition = b'attachment; filename=batch.csv'
+        return response
+
+    def get_csv_fields(self):
+        """
+        Return the list of fields to be written to CSV download.
+        """
+        fields = []
+        mapper = orm.class_mapper(self.batch_row_class)
+        for prop in mapper.iterate_properties:
+            if isinstance(prop, orm.ColumnProperty):
+                if prop.key != 'removed' and not prop.key.endswith('uuid'):
+                    fields.append(prop.key)
+        return fields
+
+    def get_csv_row(self, row, fields):
+        """
+        Return a dict for use when writing the row's data to CSV download.
+        """
+        csvrow = {}
+        for field in fields:
+            value = getattr(row, field)
+            csvrow[field] = '' if value is None else unicode(value)
+        return csvrow
+
 
 class FileBatchCrud(BatchCrud):
     """
@@ -1163,6 +1213,11 @@ 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 row data as CSV
+    config.add_route('{0}.csv'.format(route_prefix), '{0}{{uuid}}/csv'.format(url_prefix))
+    config.add_view(batch_crud, attr='csv', route_name='{0}.csv'.format(route_prefix),
+                    permission='{0}.csv'.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))