class Downloadable_File extends File {

    private static $db = array (
        'LicenceKey' => 'Text',
        'Expiry' => 'Text',
        'Ext' => 'Varchar',
        'LicenceName' => 'Text',
        'QuantityOrdered' => 'int',
        'CustomerEmail' => 'Text'
    );

    private static $has_one = array (
        'Item' => 'Item'
    );


    /**
     * Generate unique license key before each write.
     *
     * @see DataObject::onBeforeWrite()
     */

    public function onBeforeWrite() {
        parent::onBeforeWrite();

        $month = date("m");
        $year = date("Y") + 1;
        $customerName = Member::currentUser()->getName();
        $this->LicenceName = $customerName;
        $this->LicenceKey = $this->generateLicenceKey($customerName,$month,$year);

        $a_date = "$year-$month-23";
        $day =   date("t-m-Y", strtotime($a_date));
        $this->Expiry = $day;
        $this->QuantityOrdered = $QuantityOrdered;
        $customerEmail = Member::currentUser()->Email;
        $this->CustomerEmail = $customerEmail;
        }