我设法解决了这个问题。
首先，我将这个函数添加到upload/server/php/index.php文件中

protected function generate_unique_filename($filename = ""){
        $extension = "";
        if ( $filename != "" ){
            $extension = pathinfo($filename , PATHINFO_EXTENSION);
            if ( $extension != "" ){
                $extension = "." . $extension;
            }
        }           
        $characters = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
        $charactersLength = strlen($characters);
        $randomString = "";
        for ($i = 0; $i < 5 ; $i++) {
            $randomString .= $characters[rand(0, $charactersLength - 1)];
        }
        return $filename.'_'.date('siHdmy').$randomString.$extension;
}

然后我编辑了uploadhandler.php文件。我添加了一个公共变量$mytitle并替换了以下代码：

$file->name = $this->get_file_name($uploaded_file, $name, $size, $type, $error, $index, $content_range);

用这个

$this->mytitle='what-ever-text-filled-in-the-title-form-field';
$file->name = $this->generate_unique_filename($this->mytitle);