checkbox.php

См. документацию.

<?php
namespace Bitrix\Landing\Field;
 
class Checkbox extends \Bitrix\Landing\Field
{
    public function viewForm(array $params = array())
    {
        $name = \htmlspecialcharsbx(isset($params['name_format'])
                ? str_replace('#field_code#', $this->code, $params['name_format'])
                : $this->code);
        ?>
        <input type="hidden" name="<?= $name?>" value="N" />
        <input type="checkbox" <?
        ?><?= isset($params['additional']) ? $params['additional'] . ' ' : ''?><?
        ?><?= isset($params['id']) ? 'id="' . \htmlspecialcharsbx($params['id']) . '" ' : ''?><?
        ?>class="<?= isset($params['class']) ? \htmlspecialcharsbx($params['class']) : ''?>" <?
        ?>data-code="<?= \htmlspecialcharsbx($this->code)?>" <?
        ?>name="<?= $name?>" <?
        ?><?= (isset($params['disabled']) && $params['disabled']) ? ' disabled ' : ''?><?
        ?>value="Y"<?if ($this->value == 'Y'){?> checked="checked"<?}?> <?
        ?> />
        <?
    }

    public function isEmptyValue()
    {
        return $this->value !== 'Y';
    }

    public function __toString()
    {
        return $this->value == 'Y' ? 'Y' : 'N';
    }
}