File uploader for Cake PHP

FileUploadComponent.php

<?php

class FileUploadComponent extends Component {

    public $allowedTypes;
    public $maxSize;
    private $tmpFile;
    public $uploadPath;

    public function __construct() {
        $this->allowedTypes = array();
        $this->maxSize = 5 * 1024 * 1024;
        $this->uploadPath = APP . DIRECTORY_SEPARATOR . "upload" . DIRECTORY_SEPARATOR;
    }

    private function validateTypes() {
        return (in_array($this->tmpFile['type'], $this->allowedTypes));
    }

    private function validateSize() {
        return (filesize($this->tmpFile['tmp_name']) < $this->maxSize);
    } 

    public function upload($file) {
        $this->tmpFile = $file;

        if($this->tmpFile['error']) {
            throw new Exception("Image not sent");
        }

        if(!$this->validateTypes()) {
            throw new Exception("File type not allowed");
        }

        if(!$this->validateSize()) {
            throw new Exception("File size is larger than allowed");
        }

        $extension = end(explode(".", $this->tmpFile['name']));
        $tmpUploadName = md5($this->tmpFile['name'].time()) . "." . $extension;

        if(!move_uploaded_file($this->tmpFile['tmp_name'], $this->uploadPath . $tmpUploadName)) {
            throw new Exception("Unknown error");
        }

        return $tmpUploadName;
    }
}

?>