misc: add early support for form_tracking_code (#28749)

tests/test_form_pages.py

@@ -1602,6 +1602,23 @@ def test_form_invalid_tracking_code(pub):
     assert resp.location == 'http://example.net/code/%s/load' % code.id
     resp = resp.follow(status=404)
 
+def test_form_tracking_code_as_variable(pub):
+    formdef = create_formdef()
+    formdef.fields = [fields.PageField(id='0', label='1st page', type='page'),
+            fields.StringField(id='1', label='string'),
+            fields.PageField(id='2', label='2nd page', type='page'),
+            fields.CommentField(type='comment', id='3',
+                label='!{{ form_tracking_code }}!')]
+    formdef.enable_tracking_codes = True
+    formdef.store()
+    formdef.data_class().wipe()
+    resp = get_app(pub).get('/test/')
+    resp.form['f1'] = 'foobar'
+    resp = resp.form.submit('submit')
+    tracking_code = get_displayed_tracking_code(resp)
+    assert tracking_code is not None
+    assert '!%s!' % tracking_code in resp.body
+
 def test_form_draft_with_file(pub):
     user = create_user(pub)
     formdef = create_formdef()

wcs/formdata.py

@@ -684,6 +684,8 @@ class FormData(StorableObject):
 
         if self.tracking_code:
             d['form_tracking_code'] = self.tracking_code
+        elif not self.status and self.data and 'future_tracking_code' in self.data:
+            d['form_tracking_code'] = self.data['future_tracking_code']
 
         d['form_submission_backoffice'] = self.backoffice_submission
         d['form_submission_channel'] = self.submission_channel