OverviewTerms::buildForm

public OverviewTerms::buildForm(array $form, FormStateInterface $form_state, VocabularyInterface $taxonomy_vocabulary = NULL)

public function buildForm(array $form, FormStateInterface $form_state, VocabularyInterface $taxonomy_vocabulary = NULL) {
  // @todo Remove global variables when https://www.drupal.org/node/2044435 is
  //   in.
  global $pager_page_array, $pager_total, $pager_total_items;

  $form_state->set(['taxonomy', 'vocabulary'], $taxonomy_vocabulary);
  $parent_fields = FALSE;

  $page = $this->getRequest()->query->get('page') ? : 0;
  // Number of terms per page.
  $page_increment = $this->config('taxonomy.settings')->get('terms_per_page_admin');
  // Elements shown on this page.
  $page_entries = 0;
  // Elements at the root level before this page.
  $before_entries = 0;
  // Elements at the root level after this page.
  $after_entries = 0;
  // Elements at the root level on this page.
  $root_entries = 0;

  // Terms from previous and next pages are shown if the term tree would have
  // been cut in the middle. Keep track of how many extra terms we show on
  // each page of terms.
  $back_step = NULL;
  $forward_step = 0;

  // An array of the terms to be displayed on this page.
  $current_page = array();

  $delta = 0;
  $term_deltas = array();
  $tree = $this->storageController->loadTree($taxonomy_vocabulary->id(), 0, NULL, TRUE);
  $tree_index = 0;
  do {
    // In case this tree is completely empty.
    if (empty($tree[$tree_index])) {
      break;
    }
    $delta++;
    // Count entries before the current page.
    if ($page && ($page * $page_increment) > $before_entries && !isset($back_step)) {
      $before_entries++;
      continue;
    }
    // Count entries after the current page.
    elseif ($page_entries > $page_increment && isset($complete_tree)) {
      $after_entries++;
      continue;
    }

    // Do not let a term start the page that is not at the root.
    $term = $tree[$tree_index];
    if (isset($term->depth) && ($term->depth > 0) && !isset($back_step)) {
      $back_step = 0;
      while ($pterm = $tree[--$tree_index]) {
        $before_entries--;
        $back_step++;
        if ($pterm->depth == 0) {
          $tree_index--;
          // Jump back to the start of the root level parent.
          continue 2;
        }
      }
    }
    $back_step = isset($back_step) ? $back_step : 0;

    // Continue rendering the tree until we reach the a new root item.
    if ($page_entries >= $page_increment + $back_step + 1 && $term->depth == 0 && $root_entries > 1) {
      $complete_tree = TRUE;
      // This new item at the root level is the first item on the next page.
      $after_entries++;
      continue;
    }
    if ($page_entries >= $page_increment + $back_step) {
      $forward_step++;
    }

    // Finally, if we've gotten down this far, we're rendering a term on this
    // page.
    $page_entries++;
    $term_deltas[$term->id()] = isset($term_deltas[$term->id()]) ? $term_deltas[$term->id()] + 1 : 0;
    $key = 'tid:' . $term->id() . ':' . $term_deltas[$term->id()];

    // Keep track of the first term displayed on this page.
    if ($page_entries == 1) {
      $form['#first_tid'] = $term->id();
    }
    // Keep a variable to make sure at least 2 root elements are displayed.
    if ($term->parents[0] == 0) {
      $root_entries++;
    }
    $current_page[$key] = $term;
  } while (isset($tree[++$tree_index]));

  // Because we didn't use a pager query, set the necessary pager variables.
  $total_entries = $before_entries + $page_entries + $after_entries;
  $pager_total_items[0] = $total_entries;
  $pager_page_array[0] = $page;
  $pager_total[0] = ceil($total_entries / $page_increment);

  // If this form was already submitted once, it's probably hit a validation
  // error. Ensure the form is rebuilt in the same order as the user
  // submitted.
  $user_input = $form_state->getUserInput();
  if (!empty($user_input)) {
    // Get the POST order.
    $order = array_flip(array_keys($user_input['terms']));
    // Update our form with the new order.
    $current_page = array_merge($order, $current_page);
    foreach ($current_page as $key => $term) {
      // Verify this is a term for the current page and set at the current
      // depth.
      if (is_array($user_input['terms'][$key]) && is_numeric($user_input['terms'][$key]['term']['tid'])) {
        $current_page[$key]->depth = $user_input['terms'][$key]['term']['depth'];
      }
      else {
        unset($current_page[$key]);
      }
    }
  }

  $errors = $form_state->getErrors();
  $destination = $this->getDestinationArray();
  $row_position = 0;
  // Build the actual form.
  $form['terms'] = array(
    '#type' => 'table',
    '#header' => array($this->t('Name'), $this->t('Weight'), $this->t('Operations')),
    '#empty' => $this->t('No terms available. <a href=":link">Add term</a>.', array(':link' => $this->url('entity.taxonomy_term.add_form', array('taxonomy_vocabulary' => $taxonomy_vocabulary->id())))),
    '#attributes' => array(
      'id' => 'taxonomy',
    ),
  );
  foreach ($current_page as $key => $term) {
    /** @var $term \Drupal\Core\Entity\EntityInterface */
    $form['terms'][$key]['#term'] = $term;
    $indentation = array();
    if (isset($term->depth) && $term->depth > 0) {
      $indentation = array(
        '#theme' => 'indentation',
        '#size' => $term->depth,
      );
    }
    $form['terms'][$key]['term'] = array(
      '#prefix' => !empty($indentation) ? drupal_render($indentation) : '',
      '#type' => 'link',
      '#title' => $term->getName(),
      '#url' => $term->urlInfo(),
    );
    if ($taxonomy_vocabulary->getHierarchy() != VocabularyInterface::HIERARCHY_MULTIPLE && count($tree) > 1) {
      $parent_fields = TRUE;
      $form['terms'][$key]['term']['tid'] = array(
        '#type' => 'hidden',
        '#value' => $term->id(),
        '#attributes' => array(
          'class' => array('term-id'),
        ),
      );
      $form['terms'][$key]['term']['parent'] = array(
        '#type' => 'hidden',
        // Yes, default_value on a hidden. It needs to be changeable by the
        // javascript.
        '#default_value' => $term->parents[0],
        '#attributes' => array(
          'class' => array('term-parent'),
        ),
      );
      $form['terms'][$key]['term']['depth'] = array(
        '#type' => 'hidden',
        // Same as above, the depth is modified by javascript, so it's a
        // default_value.
        '#default_value' => $term->depth,
        '#attributes' => array(
          'class' => array('term-depth'),
        ),
      );
    }
    $form['terms'][$key]['weight'] = array(
      '#type' => 'weight',
      '#delta' => $delta,
      '#title' => $this->t('Weight for added term'),
      '#title_display' => 'invisible',
      '#default_value' => $term->getWeight(),
      '#attributes' => array(
        'class' => array('term-weight'),
      ),
    );
    $operations = array(
      'edit' => array(
        'title' => $this->t('Edit'),
        'query' => $destination,
        'url' => $term->urlInfo('edit-form'),
      ),
      'delete' => array(
        'title' => $this->t('Delete'),
        'query' => $destination,
        'url' => $term->urlInfo('delete-form'),
      ),
    );
    if ($this->moduleHandler->moduleExists('content_translation') && content_translation_translate_access($term)->isAllowed()) {
      $operations['translate'] = array(
        'title' => $this->t('Translate'),
        'query' => $destination,
        'url' => $term->urlInfo('drupal:content-translation-overview'),
      );
    }
    $form['terms'][$key]['operations'] = array(
      '#type' => 'operations',
      '#links' => $operations,
    );

    $form['terms'][$key]['#attributes']['class'] = array();
    if ($parent_fields) {
      $form['terms'][$key]['#attributes']['class'][] = 'draggable';
    }

    // Add classes that mark which terms belong to previous and next pages.
    if ($row_position < $back_step || $row_position >= $page_entries - $forward_step) {
      $form['terms'][$key]['#attributes']['class'][] = 'taxonomy-term-preview';
    }

    if ($row_position !== 0 && $row_position !== count($tree) - 1) {
      if ($row_position == $back_step - 1 || $row_position == $page_entries - $forward_step - 1) {
        $form['terms'][$key]['#attributes']['class'][] = 'taxonomy-term-divider-top';
      }
      elseif ($row_position == $back_step || $row_position == $page_entries - $forward_step) {
        $form['terms'][$key]['#attributes']['class'][] = 'taxonomy-term-divider-bottom';
      }
    }

    // Add an error class if this row contains a form error.
    foreach ($errors as $error_key => $error) {
      if (strpos($error_key, $key) === 0) {
        $form['terms'][$key]['#attributes']['class'][] = 'error';
      }
    }
    $row_position++;
  }

  if ($parent_fields) {
    $form['terms']['#tabledrag'][] = array(
      'action' => 'match',
      'relationship' => 'parent',
      'group' => 'term-parent',
      'subgroup' => 'term-parent',
      'source' => 'term-id',
      'hidden' => FALSE,
    );
    $form['terms']['#tabledrag'][] = array(
      'action' => 'depth',
      'relationship' => 'group',
      'group' => 'term-depth',
      'hidden' => FALSE,
    );
    $form['terms']['#attached']['library'][] = 'taxonomy/drupal.taxonomy';
    $form['terms']['#attached']['drupalSettings']['taxonomy'] = [
      'backStep' => $back_step,
      'forwardStep' => $forward_step,
    ];
  }
  $form['terms']['#tabledrag'][] = array(
    'action' => 'order',
    'relationship' => 'sibling',
    'group' => 'term-weight',
  );

  if ($taxonomy_vocabulary->getHierarchy() != VocabularyInterface::HIERARCHY_MULTIPLE && count($tree) > 1) {
    $form['actions'] = array('#type' => 'actions', '#tree' => FALSE);
    $form['actions']['submit'] = array(
      '#type' => 'submit',
      '#value' => $this->t('Save'),
      '#button_type' => 'primary',
    );
    $form['actions']['reset_alphabetical'] = array(
      '#type' => 'submit',
      '#submit' => array('::submitReset'),
      '#value' => $this->t('Reset to alphabetical'),
    );
  }

  $form['pager_pager'] = ['#type' => 'pager'];
  return $form;
}