Fatal error: "isEven" is an invalid render array key /web/core/lib/Drupal/Core/Render/Element.php

Question

we have this code in template.theme but when we go to view the web, the page show a error as this: "isEven" is an invalid render array key /web/core/lib/Drupal/Core/Render/Element.php . I dont understand very good Drupal and as works it.

function fcjc_bootstrap_preprocess_paragraph(&$variables)
{
  /** @var \Drupal\paragraphs\Entity\Paragraph $paragraph */
  $paragraph = $variables['paragraph'];
  if ($paragraph->getType() === 'image_text_full_width' || $paragraph->getType() === 'imaxe_texto_biografia_') {
    $variables['isEven'] = $variables['elements']['isEven'];
  }
}


function fcjc_bootstrap_preprocess_field__field_image_text_section(&$vars)
{
  foreach ($vars['items'] as $delta => &$item) {
    $classname = ($delta % 2 == 0 ? 'even' : 'odd');
    $item['attributes']->setAttribute('class', $classname);
    $item['content']['isEven'] = ($delta % 2 == 0);
    }
}

In paragraph.twig I have this: <div class=" image col-sm-4 col-xs-12 {% if isEven %}right-shadow{% else %}left-shadow col-sm-push-8{% endif %}">

Can Somebody can help me? please. Thx

Answer 1

It's what @Beau wrote in the comment. You have to put a # in the array key.

The code should be:

function fcjc_bootstrap_preprocess_paragraph(&$variables)
{
  /** @var \Drupal\paragraphs\Entity\Paragraph $paragraph */
  $paragraph = $variables['paragraph'];
  if ($paragraph->getType() === 'image_text_full_width' || $paragraph->getType() === 'imaxe_texto_biografia_') {
    $variables['isEven'] = $variables['elements']['#isEven'];
  }
}


function fcjc_bootstrap_preprocess_field__field_image_text_section(&$vars)
{
  foreach ($vars['items'] as $delta => &$item) {
    $classname = ($delta % 2 == 0 ? 'even' : 'odd');
    $item['attributes']->setAttribute('class', $classname);
    $item['content']['#isEven'] = ($delta % 2 == 0);
    }
}