NAME

User::Simple - Simple user sessions management

SYNOPSIS

$usr = User::Simple->new(db => $db,
                         [tbl => $user_table],
                         [durat => $duration],
                         [debug => $debug]);

$ok = $usr->ck_session($session);
$ok = $usr->ck_login($login, $passwd, [$no_sess]);
$ok = $usr->set_passwd($new_pass);
$usr->end_session;

$name = $usr->name;
$login = $usr->login;
$id = $usr->id;
$session = $usr->session;
$level = $usr->level;

$otherattrib = $user->otherattrib

DESCRIPTION

User::Simple provides a very simple framework for validating users, managing their sessions and storing a minimal set of information (this is, a meaningful user login/password pair, the user's name and privilege level) via a database. The sessions can be used as identifiers for i.e. cookies on a Web system. The passwords are stored as MD5 hashes (this means, the password is never stored in clear text).

User::Simple was originally developed with a PostgreSQL database in mind, but should work with any real DBMS. Sadly, this rules out DBD::CSV, DBD::XBase, DBD::Excel and many other implementations based on SQL::Statement - The user table requires the driver to implement primary keys and NOT NULL/UNIQUE constraints.

The functionality is split into two modules, User::Simple and User::Simple::Admin. This module provides the functionality your system will need for any interaction started by the user - Authentication, session management, querying the user's data and changing the password. Any other changes (i.e., changing the user's name, login or level) should be carried out using User::Simple::Admin.

CONSTRUCTOR

In order to create a User::Simple object, call the new argument with an active DBI (database connection) object as its only argument:

$usr = User::Simple->new(db => $db, [tbl => $table], [durat => $duration],
                         [debug => $debug]);

Of course, the database must have the right structure in it - please check User::Simple::Admin for more information.

The tbl parameter is the name of the table where the user information is stored. If not specified, it defaults to 'user_simple'.

durat is the number of minutes a user's session should last. Its default is of 30 minutes.

debug is the verbosity level of the debugging messages - The default is 2, it accepts integers between 0 and 5 (higher means more messages). Messages of high relevance (i.e. the database failing to reflect any changes we request it to make) are shown if debug is >= 1, regular failure messages are shown if debug >= 3, absolutely everything is shown if debug == 5. Be warned that when debug is set to 5, information such as cleartext passwords will be logged as well!

SESSION CREATION/DELETION

Once the object is created, we can ask it to verify that a given user is valid, either by checking against a session string or against a login/password pair::

$ok = $usr->ck_session($session);
$ok = $usr->ck_login($login, $passwd, [$no_sess]);

The optional $no_sess argument should be used if we do not want to modify the current session (or to create a new session), we want only to verify the password matches (i.e. when asking for the current password as a confirmation in order to change a user's password). It will almost always be left false.

To end a session:

$ok = $usr->end_session;

To verify whether we have successfully validated a user:

$ok = $usr->is_valid;

QUERYING THE CURRENT USER'S DATA

To check the user's attributes (name, login and ID):

$name = $usr->name;
$login = $usr->login;
$id = $usr->id;
$level = $usr->level;

You might add extra columns to the User::Simple table in your database - You will still be able to query for them in the same way:

$otherattrib = $user->otherattrib;

The access to the extra fields will be a bit slower than to the internally provided ones, as this is implemented via AUTOLOAD, and requires an extra access to the database. Keep in mind that the extra columns' names must consist of only alphanumeric characters or underscores. Don't use column names beginning with set_, as you might want to use the set_* methods in User::Simple::Admin.

Of course, beware: if the field does not exist, User::Simple will raise an error and die just as if an unknown method had been called.

To change the user's password:

$ok = $usr->set_passwd($new_pass);

Note that an empty password will not be accepted.

DEPENDS ON

Date::Calc

Digest::MD5

DBI (and a suitable DBD backend)

SEE ALSO

User::Simple::Admin for administrative routines

AUTHOR

Gunnar Wolf <gwolf@gwolf.org>

COPYRIGHT

Copyright 2005 Gunnar Wolf / Instituto de Investigaciones Económicas UNAM This module is Free Software, it can be redistributed under the same terms as Perl.