FormTestTableSelectColspanForm.php

<?php

namespace Drupal\form_test\Form;

use Drupal\Core\Form\FormStateInterface;

/**
 * Builds a form to test table selects with different column spans.
 *
 * @internal
 */
class FormTestTableSelectColspanForm extends FormTestTableSelectFormBase {

  /**
   * {@inheritdoc}
   */
  public function getFormId() {
    return '_form_test_tableselect_colspan_form';
  }

  /**
   * {@inheritdoc}
   */
  public function buildForm(array $form, FormStateInterface $form_state) {
    [
      $header,
      $options,
    ] = _form_test_tableselect_get_data();

    // Change the data so that the third column has colspan=2.
    $header['three'] = [
      'data' => 'Three',
      'colspan' => 2,
    ];
    unset($header['four']);

    // Set the each row so that column 3 is an array.
    foreach ($options as $name => $row) {
      $options[$name]['three'] = [
        $row['three'],
        $row['four'],
      ];
      unset($options[$name]['four']);
    }

    // Combine cells in row 3.
    $options['row3']['one'] = [
      'data' => $options['row3']['one'],
      'colspan' => 2,
    ];
    unset($options['row3']['two']);
    $options['row3']['three'] = [
      'data' => $options['row3']['three'][0],
      'colspan' => 2,
    ];
    unset($options['row3']['four']);
    return $this
      ->tableselectFormBuilder($form, $form_state, [
      '#header' => $header,
      '#options' => $options,
    ]);
  }

  /**
   * {@inheritdoc}
   */
  public function submitForm(array &$form, FormStateInterface $form_state) {
  }

}