Build the options form.
Overrides PluginBase::buildOptionsForm
public function buildOptionsForm(&$form, &$form_state) {
// Some form elements belong in a fieldset for presentation, but can't
// be moved into one because of the form_state['values'] hierarchy. Those
// elements can add a #fieldset => 'fieldset_name' property, and they'll
// be moved to their fieldset during pre_render.
$form['#pre_render'][] = 'views_ui_pre_render_add_fieldset_markup';
$form['admin_label'] = array(
'#type' => 'textfield',
'#title' => t('Administrative title'),
'#description' => t('This title will be displayed on the views edit page instead of the default one. This might be useful if you have the same item twice.'),
'#default_value' => $this->options['admin_label'],
'#fieldset' => 'more',
);
// This form is long and messy enough that the "Administrative title" option
// belongs in "more options" details at the bottom of the form.
$form['more'] = array(
'#type' => 'details',
'#title' => t('More'),
'#collapsible' => TRUE,
'#collapsed' => TRUE,
'#weight' => 150,
);
// Allow to alter the default values brought into the form.
drupal_alter('views_handler_options', $this->options, $view);
}