Assign permission in an entire directory inside Amazon S3 Bucket (PHP)

I'm using AWS SDK + PHP + Symfony2.

Is there a way to assign public-read permission to an entire directory that I've just uploaded to an Amazon S3 Bucket?

The code I normally use to assign a public-read permission is:

$this->s3->putObjectAcl(
    array(
        'Bucket' => $this->bucketName,
        'Key' => $destinationPath,
        'ACL' => CannedAcl::PUBLIC_READ
    )
);
Copy code

But it doesn't work if $destinationPath is a directory. Is there a way to achieve that?