Question

public function makeTweet( $DatabaseObject, $TextObject, $MessageObject)
{
    if( $DatabaseObject == NULL )
    {
        $DatabaseObject = new Database();
        $TextObject = new Text();
        $MessageObject = new Message();
    }
    $TweetObject = new ControlTweet();        
    $TweetObject->setObjects($DatabaseObject, $TextObject, $MessageObject);
    return $TweetObject;
}

Answer 1

You can add optional parameters in the function declaration like:

public function makeTweet( $DatabaseObject, $TextObject, $MessageObject = null)

Now you can either do:

$obj->makeTweet($db, $text, $messageObj);

or

$obj->makeTweet($db, $text);

This is the closest you can get in PHP.