Павел Гвоздь

$hook->addError('field_name', 'lexicon_key');
return !$hook->hasErrors();

немного схитрить используя свойство fieldNames сниппета FormIt

{'!AjaxForm' | snippet : [
    ...
    'formFields' => [
        'name' => [
            'type' => 'text',
            'label' => '',
            'placeholder' => 'Ваше имя',
            'required' => true,
        ],
        'email' => [
            'type' => 'email',
            'label' => '',
            'placeholder' => 'Ваш email',
        ],
        'phone' => [
            'type' => 'text',
            'label' => '',
            'placeholder' => 'Контактный телефон',
            'required' => true,
        ],
    ],
    ...
]}

{foreach $formFields as $fk => $fv}
    {if $fv['label']?}
        <div class="form__label-w">
            <label class="form__label">
                {$fv['label']}
            </label>
        </div>
    {/if}

    {switch $fv['type']}
        {case 'text'}
            <div class="form__input-w">
                <input class="form__input" type="text" name="{$fk}" placeholder="{$fv['placeholder']}">
            </div>

        {case 'email'}
            <div class="form__input-w">
                <input class="form__input" type="email" name="{$fk}" placeholder="{$fv['placeholder']}">
            </div>

        {case 'textarea'}
            <div class="form__input-w">
                <textarea class="form__input" name="{$fk}" placeholder="{$fv['placeholder']}"></textarea>
            </div>
    {/switch}

    <div class="form__error error_{$fk}"></div>
{/foreach}

$sp = &$scriptProperties;
switch ($modx->event->name) {
    case 'xParserOnBeforeTaskActions':
        foreach ($sp['rows'] as &$row) {
            $row['Resource'] = [];
        }
        unset($row);
        $modx->event->returnedValues = ['rows' => $sp['rows']];
        break;
}

{$_modx->resource.video | print}

<script>
    window.user = {
         id: {$_modx->user.id},
         fullname: '{$_modx->user.fullname}'
    }
</script>

потратил пару недель

<script type="text/javascript">mse2Config =