Order and sort items with tabledrag

Draggable table Form Example

Step 1 : Form build

$group_class = 'group-order-weight';

$items = [

  1 => ['id' => 1, 'label' => 'L1', 'weight' => 1],

  2 => ['id' => 2, 'label' => 'L2', 'weight' => 2],

  3 => ['id' => 3, 'label' => 'L3', 'weight' => 3],

];

// Build table.

$form['items'] = [

  '#type' => 'table',

  '#caption' => $this->t('Items'),

  '#header' => [

    $this->t('Label'),

    $this->t('ID'),

    $this->t('Weight'),

  ],

  '#empty' => $this->t('No items.'),

  '#tableselect' => FALSE,

  '#tabledrag' => [

    [

      'action' => 'order',

      'relationship' => 'sibling',

      'group' => $group_class,

    ]

  ]

];

// Build rows.

foreach ($items as $key => $value) {

  $form['items'][$key]['#attributes']['class'][] = 'draggable';

  $form['items'][$key]['#weight'] = $value['weight'];

  // Label col.

  $form['items'][$key]['label'] = [

    '#plain_text' => $value['label'],

  ];

  // ID col.

  $form['items'][$key]['id'] = [

    '#plain_text' => $value['id'], //@todo add field

  ];

  // Weight col.

  $form['items'][$key]['weight'] = [

    '#type' => 'weight',

    '#title' => $this->t('Weight for @title', ['@title' => $value['label']]),

    '#title_display' => 'invisible',

    '#default_value' => $value['weight'],

    '#attributes' => ['class' => [$group_class]],

  ];

}

Stem 2 : Form submit

$items = $form_state->getValue('items');