saplings_paragraphs.module

<?php

/**
 * @file
 * Contains saplings_paragraphs.module.
 */

use Drupal\Core\Form\FormStateInterface;

/**
 * Implements template_preprocess_paragraph() for preview view mode.
 */
function saplings_paragraphs_preprocess_paragraph__preview(array &$variables) {
  $paragraph = $variables['paragraph'];

  $field_label = '';
  if ($paragraph->hasField('sa_label') && !$paragraph->sa_label->isEmpty()) {
    $field_label = $paragraph->sa_label->value;
  }

  $summary_items = $paragraph->getSummaryItems();
  if ($field_label) {
    $summary_items['content'] = [$field_label];
  }

  // Overwrite content variables with the summary.
  $variables['content'] = [
    'summary' => [
      '#theme' => 'paragraphs_summary',
      '#summary' => $summary_items,
    ],
  ];
}

/**
 * Implements hook_field_widget_single_element_WIDGET_TYPE_form_alter().
 */
function saplings_paragraphs_field_widget_single_element_paragraphs_form_alter(array &$element, FormStateInterface $form_state, array $context) {
  if (isset($element['preview'])) {
    // Paragraphs role visibility might have denied access. Set this to true
    // to always allow access to the preview in an admin context.
    $element['preview']['#access'] = TRUE;

    // Move preview into top summary.
    $element['top']['summary']['preview'] = $element['preview'];
    unset($element['preview']);
  }
}