I’ve create a custom field form widget for an entity reference field. When only one value is allowed it shows a (filtered) select list, but I want to allow user to assign multiple reference values to that field.

In my use case I want it to be shown as checkboxes when multiple values are allowed, but by default it shows my checkboxes in a ‘add-another’ fieldset.

How can this be accomplished?

Below some code, $type is now a field setting and is manually set.

// Construct element $widget = $element; $widget['#delta'] = $delta; $type = $settings['option_limit_type'];  ... extra logic ...  switch ($type) {       case 'select':         $widget += array(           '#type' => 'select',           '#prefix' => '<div id="' . $settings[$element['#field_name']]['ajax_wrapper'] . '">',           '#suffix' => '</div>',           '#options' => $options,           '#delta' => $delta,           '#element_validate' => array('_entityreference_hierachy_option_limit_validate'),           '#default_value' =>  $saved_target_id,         );         break;       case 'checkboxes':         $widget += array(           '#type' => 'checkboxes',           '#prefix' => '<div id="' . $settings[$element['#field_name']]['ajax_wrapper'] . '">',           '#suffix' => '</div>',           '#options' => $options,           '#delta' => $delta,           '#element_validate' => array('_entityreference_hierachy_option_limit_validate'),           '#default_value' =>  $saved_target_id,         );         break;     } return $widget;