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BUG: Saving a serialized PHP array in a textarea field as text returns error

Support › General › BUG: Saving a serialized PHP array in a textarea field as text returns error

Viewing 3 posts - 1 through 3 (of 3 total)
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    Posts
  • August 4, 2026 at 4:11 AM #50144
    Ahmed E.Ahmed E.
    Participant

    Hi there,

    I have a custom model with a textarea field named 'meta_value' that I want to accept any type of text, including custom code.

    
[
            'name'              => 'Meta Value',
            'id'                => $prefix . 'meta_value',
            'type'              => 'textarea',
            'rows'               => 10,
            // 'required'          => true,
            'columns'           => 12,
            'sanitize_callback' => 'none',
         ],

    When the field has a serialized PHP Array that is saved as plain text, it returns an error on the editing page.
    Here's the complete error trace:

    
Uncaught Error: htmlspecialchars(): Argument #1 ($string) must be of type string, array given
in \wp-includes\formatting.php on line 4731

Call stack:
1. htmlspecialchars(array, 3, 'UTF-8')
wp-includes/formatting.php:4731

2. esc_textarea(array)
wp-content/plugins/meta-box-aio/vendor/meta-box/meta-box/inc/fields/textarea.php:21

3. RWMB_Textarea_Field::html(array, array)
wp-content/plugins/meta-box-aio/vendor/meta-box/meta-box/inc/field.php:533

4. RWMB_Field::call(array, 'html', array)
wp-content/plugins/meta-box-aio/vendor/meta-box/meta-box/inc/field.php:36

5. RWMB_Field::show(array, true, '7')
wp-content/plugins/meta-box-aio/vendor/meta-box/meta-box/inc/field.php:533

6. RWMB_Field::call('show', array, true, '7')
wp-content/plugins/meta-box-aio/vendor/meta-box/meta-box/inc/meta-box.php:225

7. RW_Meta_Box::show(NULL, array)
wp-admin/includes/template.php:1458

8. do_meta_boxes(WP_Screen, 'normal', NULL)
wp-content/plugins/meta-box-aio/vendor/meta-box/mb-custom-table/views/edit.php:33

9. include('C:\Users\PC\Local Si...table\views\edit.php')
wp-content/plugins/meta-box-aio/vendor/meta-box/mb-custom-table/src/Model/Admin.php:279

10. MetaBox\CustomTable\Model\Admin::render('')
wp-includes/class-wp-hook.php:341

11. WP_Hook::apply_filters('', array)
wp-includes/class-wp-hook.php:365

12. WP_Hook::do_action(array)
wp-includes/plugin.php:522

13. do_action('****')
wp-admin/admin.php:264

    I think it is caused because the plugin aggressively unserializes the values (maybe_unserialize()).

    August 4, 2026 at 9:01 PM #50146
    PeterPeter
    Moderator

    Hello Ahmed,

    Thanks for reaching out and for your feedback.

    Yes, you are correct. The function maybe_unserialize in the storage of custom table interferes with the serialized array and causes the issue. I suggest you use the custom code below to fix the issue

    
add_filter( 'rwmb_raw_meta', function ( $value, $field, $object_id ) {
      if ( ( $field['id'] ?? '' ) !== 'your_field_id' ) {
              return $value;
      }

      $storage = $field['storage'] ?? null;
      if ( ! $object_id || ! $storage instanceof \MetaBox\CustomTable\Storage ) {
              return $value;
      }

      $row = \MetaBox\CustomTable\Cache::get( $object_id, $storage->table );

      return $row[ $field['id'] ] ?? $value;
}, 10, 3 );

    I'm going to escalate the issue to the development team to fix it as soon as possible.

    August 4, 2026 at 10:04 PM #50147
    Ahmed E.Ahmed E.
    Participant

    Hello Peter,
    Thanks for your reply.

    Ok, I will be waiting for a fix in the plugin soon.

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