Img::getSearchableNode

static function getSearchableNode($block, $selector)
{
	$searchContent = [];

	$nodes = self::getNode($block, $selector);
	foreach ($nodes as $node)
	{
		if (!isset($node['alt']))
		{
			continue;
		}
		$node['alt'] = self::prepareSearchContent($node['alt']);
		if ($node['alt'] && !in_array($node['alt'], $searchContent))
		{
			$searchContent[] = $node['alt'];
		}
	}

	return $searchContent;
}