fields: add min_choices option to ItemsField (#49896)

tests/admin_pages/test_form.py

@@ -1679,6 +1679,8 @@ def test_form_edit_items_field(pub):
 
     resp = resp.click('Edit', href='1/')
     assert resp.forms[0]['label'].value == '1st field'
+    assert resp.forms[0]['min_choices'].value == '0'
+    assert resp.forms[0]['max_choices'].value == '0'
     resp.forms[0]['label'] = 'changed field'
     resp.forms[0]['required'] = False
     resp = resp.forms[0].submit('items$add_element')
@@ -1691,16 +1693,22 @@ def test_form_edit_items_field(pub):
     resp = resp.follow()
 
     assert FormDef.get(1).fields[0].label == 'changed field'
-    assert FormDef.get(1).fields[0].required == False
+    assert FormDef.get(1).fields[0].required is False
     assert FormDef.get(1).fields[0].items is None
+    assert FormDef.get(1).fields[0].min_choices == 0
+    assert FormDef.get(1).fields[0].max_choices == 0
 
     # edit and fill with one item
     resp = resp.click('Edit', href='1/')
     assert resp.forms[0]['label'].value == 'changed field'
     resp.forms[0]['items$element0'] = 'XXX'
+    resp.forms[0]['min_choices'] = 2
+    resp.forms[0]['max_choices'] = 5
     resp = resp.forms[0].submit('submit')
     assert resp.location == 'http://example.net/backoffice/forms/1/fields/#itemId_1'
     assert FormDef.get(1).fields[0].items == ['XXX']
+    assert FormDef.get(1).fields[0].min_choices == 2
+    assert FormDef.get(1).fields[0].max_choices == 5
 
     # check prefilling is only possible with Python
     resp = resp.follow()

tests/form_pages/test_all.py

@@ -526,11 +526,13 @@ def test_form_string_field_submit(pub):
 
 def test_form_items_submit(pub):
     formdef = create_formdef()
-    formdef.fields = [fields.ItemsField(id='0', label='items', type='items',
-                required=True,
-                varname='foo', items=['Foo', 'Bar', 'Three']),]
+    formdef.fields = [fields.ItemsField(
+        id='0', label='items', type='items',
+        required=True,
+        varname='foo', items=['Foo', 'Bar', 'Three', 'Four', 'Five', 'Six'])]
     formdef.store()
     formdef.data_class().wipe()
+
     page = get_app(pub).get('/test/')
     next_page = page.forms[0].submit('submit')  # but the field is required
     assert next_page.pyquery('div.error').text() == 'required field'
@@ -548,6 +550,25 @@ def test_form_items_submit(pub):
     assert data.data['0'] == ['Foo', 'Bar']
     assert data.data['0_display'] == 'Foo, Bar'
 
+    formdef.fields[0].min_choices = 2
+    formdef.fields[0].max_choices = 5
+    formdef.store()
+
+    page = get_app(pub).get('/test/')
+    page.forms[0]['f0$element0'].checked = True
+    page = page.forms[0].submit('submit')
+    assert page.pyquery('div.error').text() == 'You must select at least 2 answers.'
+    page.forms[0]['f0$element1'].checked = True
+    page.forms[0]['f0$element2'].checked = True
+    page.forms[0]['f0$element3'].checked = True
+    page.forms[0]['f0$element4'].checked = True
+    page.forms[0]['f0$element5'].checked = True
+    page = page.forms[0].submit('submit')
+    assert page.pyquery('div.error').text() == 'You must select at most 5 answers.'
+    page.forms[0]['f0$element5'].checked = False
+    page = next_page.forms[0].submit('submit').follow()
+    assert 'The form has been recorded' in page.text
+
 
 def test_form_string_with_invalid_xml_chars(pub):
     formdef = create_formdef()

wcs/fields.py

@@ -1791,6 +1791,7 @@ class ItemsField(WidgetField):
     allow_complex = True
 
     items = []
+    min_choices = 0
     max_choices = 0
     data_source = {}
     in_filters = False
@@ -1817,6 +1818,7 @@ class ItemsField(WidgetField):
 
     def perform_more_widget_changes(self, form, kwargs, edit = True):
         kwargs['options'] = self.get_options()
+        kwargs['min_choices'] = self.min_choices
         kwargs['max_choices'] = self.max_choices
         if self.data_source:
             items = data_sources.get_items(self.data_source,
@@ -1835,6 +1837,8 @@ class ItemsField(WidgetField):
                 value = self.items, required = False,
                 element_kwargs = {'render_br': False, 'size': 50},
                 add_element_label = _('Add item'))
+        form.add(IntWidget, 'min_choices', title=_('Minimum number of choices'),
+                 value=self.min_choices, required=False, size=4)
         form.add(IntWidget, 'max_choices', title = _('Maximum number of choices'),
                 value = self.max_choices, required = False, size = 4)
         form.add(data_sources.DataSourceSelectionWidget, 'data_source',
@@ -1850,9 +1854,9 @@ class ItemsField(WidgetField):
                 advanced=not(self.display_disabled_items))
 
     def get_admin_attributes(self):
-        return WidgetField.get_admin_attributes(self) + ['items',
-                'max_choices', 'data_source', 'in_filters', 'anonymise',
-                'display_disabled_items']
+        return WidgetField.get_admin_attributes(self) + [
+            'items', 'min_choices', 'max_choices', 'data_source', 'in_filters', 'anonymise',
+            'display_disabled_items']
 
     def check_admin_form(self, form):
         items = form.get_widget('items').parse()

wcs/qommon/form.py

@@ -1349,6 +1349,7 @@ class CheckboxesWidget(CompositeWidget):
             del kwargs['readonly']
             self.readonly = True
         self.inline = kwargs.get('inline', True)
+        self.min_choices = int(kwargs.get('min_choices', 0) or 0)
         self.max_choices = int(kwargs.get('max_choices', 0) or 0)
 
         self.options_with_attributes = kwargs.pop('options_with_attributes', None)
@@ -1393,6 +1394,8 @@ class CheckboxesWidget(CompositeWidget):
         self.value = values
         if self.required and not self.value:
             self.set_error(self.REQUIRED_ERROR)
+        if self.value and self.min_choices and len(self.value) < self.min_choices:
+            self.set_error(_('You must select at least %d answers.') % self.min_choices)
         if self.value and self.max_choices and len(self.value) > self.max_choices:
             self.set_error(_('You must select at most %d answers.') % self.max_choices)