forms: restore edited data early on (#48493)

tests/backoffice_pages/test_all.py

@@ -3654,6 +3654,63 @@ def test_backoffice_wfedit_and_data_source_with_user_info(pub):
         resp = resp.follow()
 
 
+def test_backoffice_wfedit_and_data_source_with_field_info(pub):
+    user = create_user(pub)
+    create_environment(pub)
+    formdef = FormDef.get_by_urlname('form-title')
+
+    formdef.fields[0].varname = 'bar'
+    formdef.fields[2].data_source = {'type': 'json',
+            'value': 'https://www.example.invalid/?xxx={{ form_var_bar }}'
+            }
+    formdef.store()
+
+    form_class = formdef.data_class()
+
+    number31 = [x for x in form_class.select() if x.data['1'] == 'FOO BAR 30'][0]
+
+    # attach a custom workflow
+    workflow = Workflow(name='wfedit')
+    st1 = workflow.add_status('Status1', number31.status.split('-')[1])
+
+    wfedit = EditableWorkflowStatusItem()
+    wfedit.id = '_wfedit'
+    wfedit.by = [user.roles[0]]
+    st1.items.append(wfedit)
+    wfedit.parent = st1
+    workflow.store()
+
+    formdef.workflow_id = workflow.id
+    formdef.store()
+
+    number31 = form_class().get(number31.id)
+    number31.data['3'] = 'EE'
+    number31.data['3_display'] = 'EE'
+    number31.store()
+
+    app = login(get_app(pub))
+
+    with mock.patch('wcs.qommon.misc.urlopen') as urlopen:
+        data = {'data': [{'id': 'DD', 'text': 'DD'}, {'id': 'EE', 'text': 'EE'}]}
+
+        def side_effect(url, *args):
+            assert '?xxx=FOO BAR 30' in url
+            return StringIO(json.dumps(data))
+
+        urlopen.side_effect = side_effect
+
+        resp = app.get('/backoffice/management/form-title/%s/' % number31.id)
+        resp = resp.form.submit('button_wfedit')
+        resp = resp.follow()
+        assert urlopen.call_count == 1
+        assert 'invalid value' not in resp
+        assert resp.form['f3'].value == 'EE'
+        resp.form['f3'].value = 'DD'
+        resp = resp.form.submit('submit')
+        assert urlopen.call_count == 2
+        resp = resp.follow()
+
+
 def test_global_listing(pub):
     if not pub.is_using_postgresql():
         pytest.skip('this requires SQL')

wcs/forms/root.py

@@ -611,6 +611,10 @@ class FormPage(Directory, FormTemplateMixin):
         formdata.prefilling_data = formdata.data.get('prefilling_data', {})
 
         if self.edit_mode:
+            if magictoken is None:
+                # restore edited data early on as it may be required to
+                # create lists with appropriate values on first page.
+                formdata.data = self.edited_data.data
             # keep associated user as it may be required as a parameter in
             # data source URLs.
             formdata.user = self.edited_data.user