Quentin Zervaas's DBO

_db = $db;
            $this->_table = $table;
            $this->_idField = $idField;
        }

        public function load($id, $field = null)
        {
            if (strlen($field) == 0)
                $field = $this->_idField;

            if ($field == $this->_idField) {
                $id = (int) $id;
                if ($id getSelectFields()),
                             $this->_table,
                             $field);

            $query = $this->_db->quoteInto($query, $id);

            return $this->_load($query);
        }

        protected function getSelectFields($prefix = '')
        {
            $fields = array($prefix . $this->_idField);
            foreach ($this->_properties as $k => $v)
                $fields[] = $prefix . $k;

            return $fields;
        }

        protected function _load($query)
        {
            $result = $this->_db->query($query);
            $row = $result->fetch();
            if (!$row)
                return false;

            $this->_init($row);

            $this->postLoad();

            return true;
        }

        public function _init($row)
        {
            foreach ($this->_properties as $k => $v) {
                $val = $row[$k];

                switch ($v['type']) {
                    case self::TYPE_TIMESTAMP:
                        if (!is_null($val))
                            $val = strtotime($val);
                        break;
                    case self::TYPE_BOOLEAN:
                        $val = (bool) $val;
                        break;
                }

                $this->_properties[$k]['value'] = $val;
            }
            $this->_id = (int) $row[$this->_idField];
        }


        public function save($useTransactions = true)
        {
            $update = $this->isSaved();

            if ($useTransactions)
                $this->_db->beginTransaction();

            if ($update)
                $commit = $this->preUpdate();
            else
                $commit = $this->preInsert();

            if (!$commit) {
                if ($useTransactions)
                    $this->_db->rollback();
                return false;
            }

            $row = array();

            foreach ($this->_properties as $k => $v) {
                if ($update && !$v['updated'])
                    continue;

                switch ($v['type']) {
                    case self::TYPE_TIMESTAMP:
                        if (!is_null($v['value'])) {
                            if ($this->_db instanceof Zend_Db_Adapter_Pdo_Pgsql)
                                $v['value'] = date('Y-m-d H:i:sO', $v['value']);
                            else
                                $v['value'] = date('Y-m-d H:i:s', $v['value']);
                        }
                        break;

                    case self::TYPE_BOOLEAN:
                        $v['value'] = (int) ((bool) $v['value']);
                        break;
                }

                $row[$k] = $v['value'];
            }

            if (count($row) > 0) {
                // perform insert/update
                if ($update) {
                    $this->_db->update($this->_table, $row, sprintf('%s = %d', $this->_idField, $this->getId()));
                }
                else {
                    $this->_db->insert($this->_table, $row);
                    $this->_id = $this->_db->lastInsertId($this->_table, $this->_idField);
                }
            }

            // update internal id

            if ($commit) {
                if ($update)
                    $commit = $this->postUpdate();
                else
                    $commit = $this->postInsert();
            }

            if ($useTransactions) {
                if ($commit)
                    $this->_db->commit();
                else
                    $this->_db->rollback();
            }

            return $commit;
        }

        public function delete($useTransactions = true)
        {
            if (!$this->isSaved())
                return false;

            if ($useTransactions)
                $this->_db->beginTransaction();

            $commit = $this->preDelete();

            if ($commit) {
                $this->_db->delete($this->_table, sprintf('%s = %d', $this->_idField, $this->getId()));
            }
            else {
                if ($useTransactions)
                    $this->_db->rollback();
                return false;
            }

            $commit = $this->postDelete();

            $this->_id = null;

            if ($useTransactions) {
                if ($commit)
                    $this->_db->commit();
                else
                    $this->_db->rollback();
            }

            return $commit;
        }

        public function isSaved()
        {
            return $this->getId() > 0;
        }

        public function getId()
        {
            return (int) $this->_id;
        }

        public function getDb()
        {
            return $this->_db;
        }

        public function __set($name, $value)
        {
            if (array_key_exists($name, $this->_properties)) {
                $this->_properties[$name]['value'] = $value;
                $this->_properties[$name]['updated'] = true;
                return true;
            }

            return false;
        }

        public function __get($name)
        {
            return array_key_exists($name, $this->_properties) ? $this->_properties[$name]['value'] : null;
        }

        protected function add($field, $default = null, $type = null)
        {
            $this->_properties[$field] = array('value'   => $default,
                                               'type'    => in_array($type, self::$types) ? $type : null,
                                               'updated' => false);
        }

        protected function preInsert()
        {
            return true;
        }

        protected function postInsert()
        {
            return true;
        }

        protected function preUpdate()
        {
            return true;
        }

        protected function postUpdate()
        {
            return true;
        }

        protected function preDelete()
        {
            return true;
        }

        protected function postDelete()
        {
            return true;
        }

        protected function postLoad()
        {
            return true;
        }

        public static function BuildMultiple($db, $class, $data)
        {
            $ret = array();

            if (!class_exists($class))
                throw new Exception('Undefined class specified: ' . $class);

            $testObj = new $class($db);

            if (!$testObj instanceof DatabaseObject)
                throw new Exception('Class does not extend from DatabaseObject');

            foreach ($data as $row) {
                $obj = new $class($db);
                $obj->_init($row);

                $ret[$obj->getId()] = $obj;
            }

            return $ret;
        }
    }

 'Member',
                                  'administrator' => 'Administrator');

        public $profile = null;
        public $_newPassword = null;

        public function __construct($db)
        {
            parent::__construct($db, 'users', 'user_id');

            $this->add('username');
            $this->add('password');
            $this->add('user_type', 'member');
            $this->add('ts_created', time(), self::TYPE_TIMESTAMP);
            $this->add('ts_last_login', null, self::TYPE_TIMESTAMP);

            $this->profile = new Profile_User($db);
        }

        protected function preInsert()
        {
            $this->_newPassword = Text_Password::create(8);
            $this->password = $this->_newPassword;
            return true;
        }

        protected function postLoad()
        {
            $this->profile->setUserId($this->getId());
            $this->profile->load();
        }

        protected function postInsert()
        {
            $this->profile->setUserId($this->getId());
            $this->profile->save(false);

            $this->sendEmail('user-register.tpl');
            return true;
        }

        protected function postUpdate()
        {
            $this->profile->save(false);
            return true;
        }

        protected function preDelete()
        {
            $this->profile->delete();
            return true;
        }

        public function sendEmail($tpl)
        {
            $templater = new Templater();
            $templater->user = $this;

            // fetch the e-mail body
            $body = $templater->render('email/' . $tpl);

            // extract the subject from the first line
            list($subject, $body) = preg_split('/\r|\n/', $body, 2);

            // now set up and send the e-mail
            $mail = new Zend_Mail();

            // set the to address and the user's full name in the 'to' line
            $mail->addTo($this->profile->email,
                         trim($this->profile->first_name . ' ' .
                              $this->profile->last_name));

            // get the admin 'from' details from the config
            $mail->setFrom(Zend_Registry::get('config')->email->from->email,
            Zend_Registry::get('config')->email->from->name);

            // set the subject and body and send the mail
            $mail->setSubject(trim($subject));
            $mail->setBodyText(trim($body));
            $mail->send();
        }

        public function createAuthIdentity()
        {
            $identity = new stdClass;
            $identity->user_id = $this->getId();
            $identity->username = $this->username;
            $identity->user_type = $this->user_type;
            $identity->first_name = $this->profile->first_name;
            $identity->last_name = $this->profile->last_name;
            $identity->email = $this->profile->email;

            return $identity;
        }

        public function loginSuccess()
        {
            $this->ts_last_login = time();
            unset($this->profile->new_password);
            unset($this->profile->new_password_ts);
            unset($this->profile->new_password_key);
            $this->save();

            $message = sprintf('Successful login attempt from %s user %s',
                               $_SERVER['REMOTE_ADDR'],
                               $this->username);

            $logger = Zend_Registry::get('logger');
            $logger->notice($message);
        }
        static public function LoginFailure($username, $code = '')
        {
            switch ($code) {
                case Zend_Auth_Result::FAILURE_IDENTITY_NOT_FOUND:
                    $reason = 'Unknown username';
                    break;
                case Zend_Auth_Result::FAILURE_IDENTITY_AMBIGUOUS:
                    $reason = 'Multiple users found with this username';
                    break;
                case Zend_Auth_Result::FAILURE_CREDENTIAL_INVALID:
                    $reason = 'Invalid password';
                    break;
                default:
                    $reason = '';
            }

            $message = sprintf('Failed login attempt from %s user %s',
                               $_SERVER['REMOTE_ADDR'],
                               $username);

            if (strlen($reason) > 0)
                $message .= sprintf(' (%s)', $reason);

            $logger = Zend_Registry::get('logger');
            $logger->warn($message);
        }

        public function fetchPassword()
        {
            if (!$this->isSaved())
                return false;

            // generate new password properties
            $this->_newPassword = Text_Password::create(8);
            $this->profile->new_password = md5($this->_newPassword);
            $this->profile->new_password_ts = time();
            $this->profile->new_password_key = md5(uniqid() .
                                                   $this->getId() .
                                                   $this->_newPassword);

            // save new password to profile and send e-mail
            $this->profile->save();
            $this->sendEmail('user-fetch-password.tpl');

            return true;
        }

        public function confirmNewPassword($key)
        {
            // check that valid password reset data is set
            if (!isset($this->profile->new_password)
                || !isset($this->profile->new_password_ts)
                || !isset($this->profile->new_password_key)) {

                return false;
            }

            // check if the password is being confirm within a day
            if (time() - $this->profile->new_password_ts > 86400)
                return false;

            // check that the key is correct
            if ($this->profile->new_password_key != $key)
                return false;

            // everything is valid, now update the account to use the new password

            // bypass the local setter as new_password is already an md5
            parent::__set('password', $this->profile->new_password);

            unset($this->profile->new_password);
            unset($this->profile->new_password_ts);
            unset($this->profile->new_password_key);

            // finally, save the updated user record and the updated profile
            return $this->save();
        }

        public function usernameExists($username)
        {
            $query = sprintf('select count(*) as num from %s where username = ?',
                             $this->_table);

            $result = $this->_db->fetchOne($query, $username);

            return $result > 0;
        }

        static public function IsValidUsername($username)
        {
            $validator = new Zend_Validate_Alnum();
            return $validator->isValid($username);
        }

        public function __set($name, $value)
        {
            switch ($name) {
                case 'password':
                    $value = md5($value);
                    break;

                case 'user_type':
                    if (!array_key_exists($value, self::$userTypes))
                        $value = 'member';
                    break;
            }

            return parent::__set($name, $value);
        }
    }
?>