将嵌套的<ul> List添加到drupal中的$ form中

Question

I have something like this. How can I make $upload_items be a nested <ul> list under Upload examples

Something like

<ul>
  <li> Upload Ex </li>
    <ul>
      <li> YAY </li>
    </ul>
</ul>

What I have now

$upload_items = array(
  'PDF',
  'Video',
  'PNG, GIF, JPG, JPEG',
);
 $step_items = array(
    'Upload Examples',
    implode('</li><li>',$upload_items),
    'Describe The Project',
    'Assign Tags',
    'School/Company',
  );
 $form['step_list'] = array(
    '#prefix' => '<ul class="step_list"><li>',
    '#markup' => implode('</li><li>', $step_items),
    '#suffix' => '</li></ul>',
   );

Also, what is an easy way to add ids to these <li>

Answer 1

You can use Drupal render arrays:

$items = array(
  array(
    'data'  => 'Item 1',
    'id'    => 'item_1',
    'class' => array('item-1')
  ),
  array(
    'data'  => 'Item 2',
    'id'    => 'item_2',
    'class' => array('item-2'),
  ),
  array(
    'data'  => 'Item 3',
    'id'    => 'item_3',
    'class' => array('item-3')
  ),
);

$render = array('#theme' => 'item_list', '#items' => $items);