paragraphs_tools-8.x-1.0-beta5/paragraphs_tools_setmode/paragraphs_tools_setmode.module

<?php

/**
 * @file
 * Contains paragraphs_tools_setmode.module..
 */

use Drupal\Core\Entity\EntityInterface;
use Drupal\Core\Entity\FieldableEntityInterface;
use Drupal\Core\Field\FieldItemListInterface;
use Drupal\Core\Field\WidgetInterface;
use Drupal\Core\Form\FormStateInterface;
use Drupal\entity_reference_revisions\EntityReferenceRevisionsFieldItemList;
use Drupal\Core\Entity\Entity\EntityFormDisplay;
use Drupal\paragraphs\Plugin\Field\FieldWidget\InlineParagraphsWidget;

/**
 * Implements hook_field_widget_form_alter().
 *
 * @param array $element
 * @param \Drupal\Core\Form\FormStateInterface $form_state
 * @param array $context
 */
function paragraphs_tools_setmode_field_widget_form_alter(&$element, FormStateInterface $form_state, $context) {
  $key = paragraphs_tools_setmode_querystring_key();
  $request = Drupal::request();
  $query = $request->query;
  if ($query->has($key)) {
    /** @var array $form */
    $form = $context['form'];
    /** @var WidgetInterface $widget */
    $widget = $context['widget'];
    /** @var FieldItemListInterface $items */
    $items = $context['items'];
    /** @var int $delta */
    $delta = $context['delta'];
    /** @var bool $default */
    $default = $context['default'];

    $field_name = $items->getName();

    $querystring = $query->get($key);
    $commands = paragraphs_tools_setmode_parse($querystring, $items->getEntity(), $errors);

    if ($errors) {
      foreach ($errors as $error) {
        \Drupal::messenger()->addError($error);
      }
      return;
    }

    if (!empty($commands[$field_name][$delta])) {
      $mode = $commands[$field_name][$delta];
    }
    elseif (!empty($commands[$field_name]['*'])) {
      $mode = $commands[$field_name]['*'];
    }
    if (!empty($mode)) {
      $mode_parents = [
        'field_storage',
        '#parents',
        '#fields',
        $field_name,
        'paragraphs',
        $delta,
        'mode'
      ];
      $form_state->set($mode_parents, $mode);

      // Voodoo...
      // @see \Drupal\Core\Entity\Entity\EntityFormDisplay::buildForm
      // @see \Drupal\paragraphs\Plugin\Field\FieldWidget\InlineParagraphsWidget::formMultipleElements
      // @see \Drupal\Core\Field\WidgetBase::formSingleElement
      $keys_to_preserve = [
        '#title',
        '#description',
        '#field_parents',
        '#required',
        '#delta',
        '#weight'
      ];
      $element = array_intersect_key($element, array_fill_keys($keys_to_preserve, TRUE));
      $element = $widget->formElement($items, $delta, $element, $form, $form_state);
    }
  }
}

/**
 * Get the query key.
 *
 * This can be made configurable later.
 *
 * @return string
 */
function paragraphs_tools_setmode_querystring_key() {
  return 'paragraphs-tools-setmode';
}

/**
 * Parse our query string.
 *
 * @todo This may get some caching.
 *
 * @param $string
 *   The query string. Syntax is like
 *   node/add/foo?paragraphs-preopen=field_par1:text|field_par1:image|field_par2:link
 * @param EntityInterface $entity
 *   THe entity to edit.
 * @param array $errors
 *   Errors returned by reference.
 * @return array
 *   An array of commands.
 */
function paragraphs_tools_setmode_parse($string, EntityInterface $entity, &$errors = NULL) {
  if (!$errors) {
    $errors = [];
  }
  $t_args = [
    '%par' => paragraphs_tools_setmode_querystring_key(),
  ];
  if (!is_string($string) || !$string) {
    $errors[] = t('Query parameter %par must be a nonempty string.', $t_args);
    return [];
  }
  if (!$entity instanceof FieldableEntityInterface) {
    $errors[] = t('Query parameter %par must only be used for fieldable entities.', $t_args);
    return [];
  }
  /** @var FieldableEntityInterface $entity */
  $form_entity_type = $entity->getEntityType()->id();
  $t_args['%type'] = $form_entity_type;
  $t_args['%bundle'] = $entity->bundle();

  $chunks = explode('|', $string);
  $commands = [];
  foreach ($chunks as $chunk) {
    $t_args['%chunk'] = $chunk;
    $parts = explode(':', $chunk);
    if (count($parts) == 3) {
      $parts[] = '*';
    }
    if (count($parts) == 4) {
      // That's good.
    }
    else {
      $errors[] = t('Query parameter %par: Can not understand %chunk.', $t_args);
      continue;
    }

    list($mode, $entity_type, $field_name, $delta) = $parts;
    if ($form_entity_type !== $entity_type) {
      // This does not concern us.
      continue;
    }
    $t_args['%mode'] = $mode;
    $t_args['%field'] = $field_name;
    $t_args['%delta'] = $delta;

    $modes = ['edit', 'preview', 'closed', 'collapsed', 'remove'];
    if (!in_array($mode, $modes)) {
      $t_args['%modes'] = implode(', ', $modes);
      $errors[] = t('Query parameter %par: Mode %mode not allowed. Allowed values are: %modes.', $t_args);
      continue;
    }

    if (!$entity->hasField($field_name)) {
      $errors[] = t('Query parameter %par: %type bundle %bundle does not have field %field.', $t_args);
      continue;
    }

    /** @var FieldItemListInterface $field */
    $field = $entity->get($field_name);
    if (!(paragraphs_tools_setmode_field_is_paragraph($field))) {
      $errors[] = t('Query parameter %par: Field %field must be of type paragraph.', $t_args);
      continue;
    }
    /** @var EntityReferenceRevisionsFieldItemList $field */

    if ($delta === '*') {
      // Fine.
    }
    elseif (preg_match('/-?[0-9]+', $delta)) {
      // Good. We voluntarily allow leading zeros here and do not check if the
      // delta really exists.
      if ($delta < 0) {
        $delta += $field->count();
      }
    }
    else {
      $errors[] = t('Query parameter %par: Delta %delta not allowed. Must be integer, "*" or omitted.', $t_args);
      continue;
    }

    $commands[$field_name][$delta] = $mode;
  }
  return $commands;
}

/**
 * Check if field is paragraph items.
 *
 * @param FieldItemListInterface $field
 * @return bool
 */
function paragraphs_tools_setmode_field_is_paragraph(FieldItemListInterface $field) {
  $field_is_entity_reference_revisions = $field instanceof EntityReferenceRevisionsFieldItemList;
  $field_has_paragraph_handler = $field->getItemDefinition()
    ->getSetting('handler') === 'default:paragraph';
  return $field_is_entity_reference_revisions && $field_has_paragraph_handler;
}