protected function _addUnit($id, $columns, $parent = null, $before = 0, $after = 0, $first = false, $last = false)
{
if ($parent == null) {
$div = $this->container->addChild('div');
} else {
$div = $parent->addChild('div');
}
$class = $this->makeClass($columns, $this->unitClass, $before, $after, $first, $last);
//load the content from the placeholder
$placeholderKey = $id . '_content';
$content = $this->view->placeholder($placeholderKey);
if (!empty($content)) {
$innerContent = $div->addChild('div', $content);
$innerContent->addAttribute('class', 'innerContent');
} else {
$spacer = $div->addChild('div');
$spacer->addAttribute('class', 'spacer');
}
$div->addAttribute('class', $class);
$div->addAttribute('id', $id);
return $div;
}