wf: accept empty values in mapping of edit card action (#46031)

tests/test_workflows_admin_pages.py

@@ -1477,11 +1477,19 @@ def test_workflows_global_actions_external_workflow_action(pub):
 def test_workflows_edit_carddata_action(pub):
     create_superuser(pub)
     Workflow.wipe()
+    CardDef.wipe()
 
     wf = Workflow(name='edit card')
     st = wf.add_status('Update card', 'st')
     wf.store()
 
+    carddef = CardDef()
+    carddef.name = 'My card'
+    carddef.fields = [
+        fields.StringField(id='1', label='string'),
+    ]
+    carddef.store()
+
     app = login(get_app(pub))
 
     resp = app.get('/backoffice/workflows/%s/status/%s/' % (wf.id, st.id))
@@ -1489,6 +1497,15 @@ def test_workflows_edit_carddata_action(pub):
 
     resp.forms[0]['action-formdata-action'] = 'Edit Card Data'
     resp = resp.forms[0].submit().follow()
+    assert 'Edit Card Data (not configured)' in resp.text
+
+    resp = app.get('/backoffice/workflows/%s/status/%s/items/1/' % (wf.id, st.id))
+    resp.forms[0]['formdef_slug'] = 'my-card'
+    resp = resp.forms[0].submit('submit')
+    assert 'Leaving the field blank will empty the value.' in resp.text
+    resp.forms[0]['mappings$element0$field_id'] = '1'
+    resp = resp.forms[0].submit('submit').follow()
+    assert 'Edit Card Data (not configured)' not in resp.text
 
 
 def test_workflows_criticality_levels(pub):

wcs/wf/create_formdata.py

@@ -44,6 +44,7 @@ class Mapping(object):
 class MappingWidget(CompositeWidget):
     def __init__(self, name, value=None, to_formdef=None, **kwargs):
         value = value or Mapping(None, '')
+        self.accept_empty_value = kwargs.pop('accept_empty_value', False)
         super(MappingWidget, self).__init__(name, value, **kwargs)
 
         to_fields = self._fields_to_options(to_formdef)
@@ -54,10 +55,15 @@ class MappingWidget(CompositeWidget):
                  value=value.field_id,
                  options=to_fields)
 
+        placeholder = ''
+        if self.accept_empty_value:
+            placeholder = _('Leaving the field blank will empty the value.')
+
         self.add(ComputedExpressionWidget,
                  name='expression',
                  title=_('Expression'),
-                 value=value.expression)
+                 value=value.expression,
+                 value_placeholder=placeholder)
 
     def _fields_to_options(self, formdef):
         return [(None, '---', '')] + [
@@ -65,7 +71,7 @@ class MappingWidget(CompositeWidget):
 
     def _parse(self, request):
         super(MappingWidget, self)._parse(request)
-        if self.get('field_id') is not None and self.get('expression') is not None:
+        if self.get('field_id') is not None and self.accept_empty_value or self.get('expression') is not None:
             self.value = Mapping(field_id=self.get('field_id'), expression=self.get('expression'))
         else:
             self.value = None
@@ -87,11 +93,13 @@ class MappingsWidget(WidgetListAsTable):
             # reorder mappings based on to_formdef fields order
             value.sort(key=lambda mapping: self.ranks.get(str(mapping.field_id), 9999))
 
+        accept_empty_value = kwargs.pop('accept_empty_value', False)
         super(MappingsWidget, self).__init__(
             name,
             element_type=MappingWidget,
             element_kwargs={
                 'to_formdef': to_formdef,
+                'accept_empty_value': accept_empty_value,
             },
             **kwargs)
 
@@ -197,6 +205,7 @@ class CreateFormdataWorkflowStatusItem(WorkflowStatusItem):
     formdef_slug = None
     formdef_label = N_('Form')
     mappings_label = N_('Mappings to new form fields')
+    accept_empty_value = False
     varname_hint = N_('This is used to get linked forms in expressions.')
 
     draft = False
@@ -256,6 +265,7 @@ class CreateFormdataWorkflowStatusItem(WorkflowStatusItem):
         if 'mappings' in parameters and formdef:
             widget = form.add(MappingsWidget, '%smappings' % prefix,
                      title=_(self.mappings_label),
+                     accept_empty_value=self.accept_empty_value,
                      to_formdef=formdef,
                      value=self.mappings)
             if form.is_submitted() and get_request().form.get('map_fields_by_varname') != 'yes':

wcs/wf/edit_carddata.py

@@ -14,7 +14,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program; if not, see <http://www.gnu.org/licenses/>.
 
-from wcs.qommon import _
+from ..qommon import _
 from quixote import get_publisher
 
 from wcs.workflows import register_item_class
@@ -28,6 +28,7 @@ class EditCarddataWorkflowStatusItem(CreateCarddataWorkflowStatusItem, ExternalW
     description = _('Edit Card Data')
     key = 'edit_carddata'
     mappings_label = _('Mappings to card fields')
+    accept_empty_value = True
 
     @classmethod
     def is_available(cls, workflow=None):