FieldtypeFieldsetOpen

None — stores no data.

Close fields are created, renamed, and deleted automatically alongside their paired open field. The close field is always named {opener_name}_END.

You only interact with close fields to position them within a template's field order — drag them to wherever you want the group to end.

Create the opener with $fields->new() or $fields->newField(). Do not manually create the close field as an independent field unless you are repairing old data; let the opener fieldtype create the paired close field.

// Create and save a fieldset opener named "details"
/** @var Field $open */
$open = $fields->new('FieldsetOpen', 'details', 'Details');

// Saving the opener creates/repairs the paired close field: details_END
/** @var Field $close */
$close = $fields->get('details_END');

The same pattern works for tabs:

/** @var Field $tab */
$tab = $fields->new('FieldsetTabOpen', 'seo', [
    'label' => 'SEO',
    'modal' => false,
]);

/** @var Field $tabClose */
$tabClose = $fields->get('seo_END');

If you use $fields->newField() because you need to configure before saving, save the opener before expecting the close field to exist:

$open = $fields->newField('FieldsetOpen', 'details', 'Details');
$open->collapsed = Inputfield::collapsedYes;
$fields->save($open);

$close = $fields->get('details_END');

Adding to a fieldgroup

When adding a fieldset to a template or fieldgroup in code, add fields in the exact visual order you want:

1. Add the open field.
2. Add the content fields that belong inside the fieldset.
3. Add the close field.

$fieldgroup = $templates->get('product')->fieldgroup;
$open = $fields->get('details');
$close = $fields->get('details_END');

$fieldgroup->add($open);
$fieldgroup->add('summary');
$fieldgroup->add('body');
$fieldgroup->add($close);
$fieldgroup->save();

Do not add only the opener and assume the close field will be positioned correctly for a programmatic fieldgroup change. The admin UI has convenience hooks for this, but migration code should add the opener, inner fields, and closer explicitly.

Repairing a missing close field

If a previous migration or partial failure left an opener without its {name}_END field, saving the opener repairs it:

$open = $fields->get('details');
$fields->save($open);
$close = $fields->get('details_END');

You can also call the fieldtype helper directly when you need the close field immediately:

/** @var FieldtypeFieldsetOpen $fieldtype */
$fieldtype = $open->type;
$close = $fieldtype->getFieldsetCloseField($open, true);

After repairing a missing close field, make sure the fieldgroup contains the close field in the correct position. A valid fieldgroup order is always opener, inner fields, closer.

Deleting programmatically

When deleting a fieldset in code, remove both fields yourself. Remove them from any fieldgroups before deleting the field definitions.

$open = $fields->get('details');
$close = $fields->get('details_END');

foreach([ $open, $close ] as $field) {
    if(!$field || !$field->id) continue;
    foreach($field->getFieldgroups() as $fieldgroup) {
        $fieldgroup->remove($field);
        $fieldgroup->save();
    }
}

if($open && $open->id) $fields->delete($open);
if($close && $close->id) $fields->delete($close);

• Close fields appear under the "Advanced" filter in the Fields list.
• In the admin UI, do not rename or delete close fields directly — manage them via the open field. In migration code, you may need to reference the close field directly for ordering, repair, or explicit cleanup.