tests/backoffice_pages/test_all.py

@@ -1689,6 +1689,33 @@ def test_backoffice_handling(pub):
     assert 'HELLO WORLD' in resp.text
 
 
+def test_backoffice_parallel_handling(pub, freezer):
+    create_user(pub)
+    create_environment(pub)
+    form_class = FormDef.get_by_urlname('form-title').data_class()
+    number31 = [x for x in form_class.select() if x.data['1'] == 'FOO BAR 30'][0]
+    app = login(get_app(pub))
+    resp = app.get('/backoffice/management/form-title/')
+    assert re.findall(r'<tbody.*\/tbody>', resp.text, re.DOTALL)[0].count('<tr') == 17
+
+    # open formdata twice
+    resp2 = resp.click(href='%s/' % number31.id)
+    resp3 = resp.click(href='%s/' % number31.id)
+
+    freezer.move_to(datetime.timedelta(seconds=10))
+    resp2.forms[0]['comment'] = 'HELLO WORLD'
+    resp2 = resp2.forms[0].submit('button_accept')
+    resp2 = resp2.follow()
+
+    resp3.forms[0]['comment'] = 'HELLO WORLD'
+    resp3 = resp3.forms[0].submit('button_accept')
+    assert resp3.pyquery('.global-errors summary').text() == 'Error: parallel execution.'
+    assert (
+        resp3.pyquery('.global-errors summary + p').text()
+        == 'Another action has been performed on this form in the meantime and data may have been changed.'
+    )
+
+
 def test_backoffice_handling_global_action(pub):
     create_user(pub)
 

tests/workflow/test_form.py

@@ -461,6 +461,7 @@ def test_frontoffice_workflow_form_with_impossible_condition(pub):
 
     formdata = formdef.data_class()()
     formdata.user_id = user.id
+    formdata.just_created()
     formdata.status = 'wf-new'
     formdata.store()
 

wcs/backoffice/data_management.py

@@ -420,6 +420,9 @@ class CardBackOfficeStatusPage(FormBackOfficeStatusPage):
     sidebar_recorded_by_agent_message = _(
         'The card has been recorded on %(date)s with the identifier %(identifier)s by %(agent)s.'
     )
+    replay_detailed_message = _(
+        'Another action has been performed on this card in the meantime and data may have been changed.'
+    )
 
     def should_fold_summary(self, mine, request_user):
         return False

wcs/forms/common.py

@@ -36,7 +36,7 @@ from wcs.qommon.admin.texts import TextsDirectory
 from wcs.qommon.upload_storage import get_storage_object
 from wcs.utils import record_timings
 from wcs.wf.editable import EditableWorkflowStatusItem
-from wcs.workflows import RedisplayFormException
+from wcs.workflows import RedisplayFormException, ReplayException
 
 from ..qommon import _, audit, errors, misc, template
 
@@ -166,6 +166,10 @@ class FormStatusPage(Directory, FormTemplateMixin):
     history_templates = ['wcs/formdata_history.html']
     status_templates = ['wcs/formdata_status.html']
 
+    replay_detailed_message = _(
+        'Another action has been performed on this form in the meantime and data may have been changed.'
+    )
+
     def __init__(self, formdef, filled, register_workflow_subdirs=True, custom_view=None, parent_view=None):
         get_publisher().substitutions.feed(filled)
         self.formdef = formdef
@@ -726,7 +730,18 @@ class FormStatusPage(Directory, FormTemplateMixin):
 
     def submit(self, form):
         user = get_request().user
-        next_url = self.filled.handle_workflow_form(user, form)
+        next_url = None
+        try:
+            next_url = self.filled.handle_workflow_form(user, form)
+        except ReplayException:
+            raise RedisplayFormException(
+                form=form,
+                error={
+                    'summary': _('Error: parallel execution.'),
+                    'details': self.replay_detailed_message,
+                },
+            )
+
         if next_url:
             return next_url
         if form.has_errors():

wcs/workflows.py

@@ -201,6 +201,10 @@ class RedisplayFormException(Exception):
             form.add_global_errors([error])
 
 
+class ReplayException(Exception):
+    pass
+
+
 def get_role_dependencies(roles):
     for role_id in roles or []:
         if not role_id:
@@ -2349,6 +2353,7 @@ class SerieOfActionsMixin:
     def get_action_form(self, filled, user, displayed_fields=None):
         form = Form(enctype='multipart/form-data', use_tokens=False)
         form.attrs['id'] = 'wf-actions'
+        form.add_hidden('_ts', str(time.mktime(filled.last_update_time)))
         for item in self.items:
             if not item.check_auth(filled, user):
                 continue
@@ -2394,6 +2399,8 @@ class SerieOfActionsMixin:
         return messages
 
     def handle_form(self, form, filled, user, evo):
+        if form.get('_ts') != str(time.mktime(filled.last_update_time)):
+            raise ReplayException()
         evo.time = time.localtime()
         evo.set_user(formdata=filled, user=user, check_submitter=get_request().is_in_frontoffice())
         if not filled.evolution: