How to Fix PHP Deprecated : Factory::getDocument() is deprecated

Question

How can I fix the following deprecation error generated by my php code?

Factory::getDocument() is deprecated

$app = Factory::getApplication();
$wa = $app->getDocument()->getWebAssetManager();

if (!$wa->assetExists('script', 'keyselectmodal'))
{
    $document = Factory::getDocument();
}

Answer 1

Use Joomla\CMS\Application\WebApplication::getDocument(). In your code you're already doing this with $app->getDocument().

Answer 2

You can use this:

use Joomla\CMS\Factory;
$app = Factory::getApplication();
$document = $app->getDocument();

Or this:

use Joomla\CMS\Factory;
use Joomla\CMS\Document\FactoryInterface;
$container = Factory::getApplication()->getContainer();
$documentFactory = $container->get(FactoryInterface::class);
$document = $documentFactory->getDocument();

You may notice there's an "Undefined method" error in Intelephense despite it being defined and valid.