RenderElementHelper.php

<?php

namespace Drupal\inline_form_errors;

use Drupal\Core\Form\FormStateInterface;

/**
 * Provides functionality to process render elements.
 */
class RenderElementHelper {
    
    /**
     * Alters the element type info.
     *
     * @param array $info
     *   An associative array with structure identical to that of the return value
     *   of \Drupal\Core\Render\ElementInfoManagerInterface::getInfo().
     */
    public function alterElementInfo(array &$info) {
        foreach ($info as $element_type => $element_info) {
            $info[$element_type]['#process'][] = [
                static::class,
                'processElement',
            ];
        }
    }
    
    /**
     * Process all render elements.
     *
     * @param array $element
     *   An associative array containing the properties and children of the
     *   element. Note that $element must be taken by reference here, so processed
     *   child elements are taken over into $form_state.
     * @param \Drupal\Core\Form\FormStateInterface $form_state
     *   The current state of the form.
     * @param array $complete_form
     *   The complete form structure.
     *
     * @return array
     *   The processed element.
     */
    public static function processElement(array &$element, FormStateInterface $form_state, array &$complete_form) {
        // Prevent displaying inline form errors when disabled for the whole form.
        if (!empty($complete_form['#disable_inline_form_errors'])) {
            $element['#error_no_message'] = TRUE;
        }
        return $element;
    }

}