CI_Session Class Reference

List of all members.

Public Member Functions
	CI_Session ()
	Session Constructor.
	sess_run ()
	Run the session routines.
	sess_read ()
	Fetch the current session data if it exists.
	sess_write ()
	Write the session cookie.
	sess_create ()
	Create a new session.
	sess_update ()
	Update an existing session.
	sess_destroy ()
	Destroy the current session.
	sess_gc ()
	Garbage collection.
	userdata ($item)
	Fetch a specific item from the session array.
	all_userdata ()
	Fetch all session data.
	set_userdata ($newdata=array(), $newval= '')
	Add or change data in the "userdata" array.
	unset_userdata ($newdata=array())
	Delete a session variable from the "userdata" array.
	strip_slashes ($vals)
	Strip slashes.
	set_flashdata ($newdata=array(), $newval= '')
	Add or change flashdata, only available until the next request.
	keep_flashdata ($key)
	Keeps existing flashdata available to next request.
	flashdata ($key)
	Fetch a specific flashdata item from the session array.
	_flashdata_mark ()
	Identifies flashdata as 'old' for removal when _flashdata_sweep() runs.
	_flashdata_sweep ()
	Removes all flashdata marked as 'old'.
Public Attributes
	$CI
	$now
	$encryption = TRUE
	$use_database = FALSE
	$session_table = FALSE
	$sess_length = 7200
	$sess_cookie = 'ci_session'
	$userdata = array()
	$gc_probability = 5
	$flashdata_key = 'flash'
	$time_to_update = 300

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Detailed Description

Definition at line 27 of file Session.php.

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Member Function Documentation

CI_Session::_flashdata_mark

(

)

Identifies flashdata as 'old' for removal when _flashdata_sweep() runs.

private

Returns:

void

Definition at line 613 of file Session.php.

References $userdata, all_userdata(), set_userdata(), and unset_userdata().

Referenced by sess_run().

    {
                $userdata = $this->all_userdata();
        foreach ($userdata as $name => $value)
        {
            $parts = explode(':new:', $name);
            if (is_array($parts) && count($parts) === 2)
            {
                $new_name = $this->flashdata_key.':old:'.$parts[1];
                $this->set_userdata($new_name, $value);
                $this->unset_userdata($name);
            }
        }
    }

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CI_Session::_flashdata_sweep

(

)

Removes all flashdata marked as 'old'.

private

Returns:

void

Definition at line 637 of file Session.php.

References $userdata, all_userdata(), and unset_userdata().

Referenced by sess_run().

    {
                $userdata = $this->all_userdata();
        foreach ($userdata as $key => $value)
        {
            if (strpos($key, ':old:'))
            {
                $this->unset_userdata($key);
            }
        }

    }

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CI_Session::all_userdata

(

)

Fetch all session data.

public

Returns:

mixed

Definition at line 453 of file Session.php.

References userdata().

Referenced by _flashdata_mark(), and _flashdata_sweep().

        {
        return ( ! isset($this->userdata)) ? FALSE : $this->userdata;
        }

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CI_Session::CI_Session

(

)

Session Constructor.

The constructor runs the session routines automatically whenever the class is instantiated.

Definition at line 47 of file Session.php.

References get_instance(), log_message(), and sess_run().

        {
                $this->CI =& get_instance();

                log_message('debug', "Session Class Initialized");
                $this->sess_run();
        }

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CI_Session::flashdata

(

$

key

)

Fetch a specific flashdata item from the session array.

public

Parameters:

string

Returns:

string

Definition at line 598 of file Session.php.

References $flashdata_key, and userdata().

    {
        $flashdata_key = $this->flashdata_key.':old:'.$key;
        return $this->userdata($flashdata_key);
    }

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CI_Session::keep_flashdata

(

$

key

)

Keeps existing flashdata available to next request.

public

Parameters:

string

Returns:

void

Definition at line 576 of file Session.php.

References set_userdata(), and userdata().

    {
                // 'old' flashdata gets removed.  Here we mark all 
                // flashdata as 'new' to preserve it from _flashdata_sweep()
                // Note the function will return FALSE if the $key 
                // provided cannot be found
        $old_flashdata_key = $this->flashdata_key.':old:'.$key;
        $value = $this->userdata($old_flashdata_key);

        $new_flashdata_key = $this->flashdata_key.':new:'.$key;
        $this->set_userdata($new_flashdata_key, $value);
    }

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CI_Session::sess_create

(

)

Create a new session.

public

Returns:

void

Definition at line 326 of file Session.php.

References sess_write(), and userdata().

Referenced by sess_run().

        {       
                $sessid = '';
                while (strlen($sessid) < 32)
                {
                        $sessid .= mt_rand(0, mt_getrandmax());
                }
        
                $this->userdata = array(
                                                        'session_id'    => md5(uniqid($sessid, TRUE)),
                                                        'ip_address'    => $this->CI->input->ip_address(),
                                                        'user_agent'    => substr($this->CI->input->user_agent(), 0, 50),
                                                        'last_activity' => $this->now
                                                        );
                
                
                // Save the session in the DB if needed
                if ($this->use_database === TRUE)
                {
                        $this->CI->db->query($this->CI->db->insert_string($this->session_table, $this->userdata));
                }
                        
                // Write the cookie
                $this->sess_write();
        }

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CI_Session::sess_destroy

(

)

Destroy the current session.

public

Returns:

void

Definition at line 394 of file Session.php.

Referenced by sess_read().

        {
                setcookie(
                                        $this->sess_cookie,
                                        addslashes(serialize(array())),
                                        ($this->now - 31500000),
                                        $this->CI->config->item('cookie_path'),
                                        $this->CI->config->item('cookie_domain'),
                                        0
                                );
        }

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CI_Session::sess_gc

(

)

Garbage collection.

This deletes expired session rows from database if the probability percentage is met

public

Returns:

void

Definition at line 417 of file Session.php.

References log_message().

Referenced by sess_run().

        {
                srand(time());
                if ((rand() % 100) < $this->gc_probability)
                {
                        $expire = $this->now - $this->sess_length;
                        
                        $this->CI->db->where("last_activity < {$expire}");
                        $this->CI->db->delete($this->session_table);

                        log_message('debug', 'Session garbage collection performed.');
                }
        }

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CI_Session::sess_read

(

)

Fetch the current session data if it exists.

public

Returns:

void

Definition at line 183 of file Session.php.

References log_message(), sess_destroy(), strip_slashes(), and userdata().

Referenced by sess_run().

        {       
                // Fetch the cookie
                $session = $this->CI->input->cookie($this->sess_cookie);
                
                if ($session === FALSE)
                {
                        log_message('debug', 'A session cookie was not found.');
                        return FALSE;
                }
                
                // Decrypt and unserialize the data
                if ($this->encryption == TRUE)
                {
                        $session = $this->CI->encrypt->decode($session);
                }
                else
                {       
                        // encryption was not used, so we need to check the md5 hash
                        $hash = substr($session, strlen($session)-32); // get last 32 chars
                        $session = substr($session, 0, strlen($session)-32);

                        // Does the md5 hash match?  This is to prevent manipulation of session data
                        // in userspace
                        if ($hash !==  md5($session.$this->CI->config->item('encryption_key')))
                        {
                                log_message('error', 'The session cookie data did not match what was expected. This could be a possible hacking attempt.');
                                $this->sess_destroy();
                                return FALSE;
                        }
                }
                
                $session = @unserialize($this->strip_slashes($session));
                
                if ( ! is_array($session) OR ! isset($session['last_activity']))
                {
                        log_message('error', 'The session cookie data did not contain a valid array. This could be a possible hacking attempt.');
                        return FALSE;
                }
                
                // Is the session current?
                if (($session['last_activity'] + $this->sess_length) < $this->now)
                {
                        $this->sess_destroy();
                        return FALSE;
                }

                // Does the IP Match?
                if ($this->CI->config->item('sess_match_ip') == TRUE AND $session['ip_address'] != $this->CI->input->ip_address())
                {
                        $this->sess_destroy();
                        return FALSE;
                }
                
                // Does the User Agent Match?
                if ($this->CI->config->item('sess_match_useragent') == TRUE AND trim($session['user_agent']) != trim(substr($this->CI->input->user_agent(), 0, 50)))
                {
                        $this->sess_destroy();
                        return FALSE;
                }
                
                // Is there a corresponding session in the DB?
                if ($this->use_database === TRUE)
                {
                        $this->CI->db->where('session_id', $session['session_id']);
                                        
                        if ($this->CI->config->item('sess_match_ip') == TRUE)
                        {
                                $this->CI->db->where('ip_address', $session['ip_address']);
                        }

                        if ($this->CI->config->item('sess_match_useragent') == TRUE)
                        {
                                $this->CI->db->where('user_agent', $session['user_agent']);
                        }
                        
                        $query = $this->CI->db->get($this->session_table);

                        if ($query->num_rows() == 0)
                        {
                                $this->sess_destroy();
                                return FALSE;
                        }
                        else
                        {
                                $row = $query->row();
                                if (($row->last_activity + $this->sess_length) < $this->now)
                                {
                                        $this->CI->db->where('session_id', $session['session_id']);
                                        $this->CI->db->delete($this->session_table);
                                        $this->sess_destroy();
                                        return FALSE;
                                }
                        }
                }
        
                // Session is valid!
                $this->userdata = $session;
                unset($session);
                
                return TRUE;
        }

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CI_Session::sess_run

(

)

Run the session routines.

public

Returns:

void

Definition at line 63 of file Session.php.

References $now, _flashdata_mark(), _flashdata_sweep(), log_message(), sess_create(), sess_gc(), sess_read(), sess_update(), and userdata().

Referenced by CI_Session().

        {
                /*
                 *  Set the "now" time
                 *
                 * It can either set to GMT or time(). The pref
                 * is set in the config file.  If the developer
                 * is doing any sort of time localization they
                 * might want to set the session time to GMT so
                 * they can offset the "last_activity" time
                 * based on each user's locale.
                 *
                 */

                if (is_numeric($this->CI->config->item('sess_time_to_update')))
                {
                        $this->time_to_update = $this->CI->config->item('sess_time_to_update');
                }

                if (strtolower($this->CI->config->item('time_reference')) == 'gmt')
                {
                        $now = time();
                        $this->now = mktime(gmdate("H", $now), gmdate("i", $now), gmdate("s", $now), gmdate("m", $now), gmdate("d", $now), gmdate("Y", $now));
        
                        if (strlen($this->now) < 10)
                        {
                                $this->now = time();
                                log_message('error', 'The session class could not set a proper GMT timestamp so the local time() value was used.');
                        }
                }
                else
                {
                        $this->now = time();
                }
                
                /*
                 *  Set the session length
                 *
                 * If the session expiration is set to zero in
                 * the config file we'll set the expiration
                 * two years from now.
                 *
                 */
                $expiration = $this->CI->config->item('sess_expiration');
                
                if (is_numeric($expiration))
                {
                        if ($expiration > 0)
                        {
                                $this->sess_length = $this->CI->config->item('sess_expiration');
                        }
                        else
                        {
                                $this->sess_length = (60*60*24*365*2);
                        }
                }
                
                // Do we need encryption?
                $this->encryption = $this->CI->config->item('sess_encrypt_cookie');
        
                if ($this->encryption == TRUE)  
                {
                        $this->CI->load->library('encrypt');
                }               

                // Are we using a database?
                if ($this->CI->config->item('sess_use_database') === TRUE AND $this->CI->config->item('sess_table_name') != '')
                {
                        $this->use_database = TRUE;
                        $this->session_table = $this->CI->config->item('sess_table_name');
                        $this->CI->load->database();
                }
                
                // Set the cookie name
                if ($this->CI->config->item('sess_cookie_name') != FALSE)
                {
                        $this->sess_cookie = $this->CI->config->item('cookie_prefix').$this->CI->config->item('sess_cookie_name');
                }
        
                /*
                 *  Fetch the current session
                 *
                 * If a session doesn't exist we'll create
                 * a new one.  If it does, we'll update it.
                 *
                 */
                if ( ! $this->sess_read())
                {
                        $this->sess_create();
                }
                else
                {       
                        // We only update the session every five minutes
                        if (($this->userdata['last_activity'] + $this->time_to_update) < $this->now)
                        {
                                $this->sess_update();
                        }
                }
                
                // Delete expired sessions if necessary
                if ($this->use_database === TRUE)
                {               
                        $this->sess_gc();
                }

                // Delete 'old' flashdata (from last request)
        $this->_flashdata_sweep();
        
        // Mark all new flashdata as old (data will be deleted before next request)
        $this->_flashdata_mark();
        }

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CI_Session::sess_update

(

)

Update an existing session.

public

Returns:

void

Definition at line 360 of file Session.php.

References sess_write(), and userdata().

Referenced by sess_run().

        {       
                // Save the old session id so we know which record to 
                // update in the database if we need it
                $old_sessid = $this->userdata['session_id'];
                $new_sessid = '';
                while (strlen($new_sessid) < 32)
                {
                        $new_sessid .= mt_rand(0, mt_getrandmax());
                }
                $new_sessid = md5(uniqid($new_sessid, TRUE));
                
        // Update the session data in the session data array
                $this->userdata['session_id'] = $new_sessid;
                $this->userdata['last_activity'] = $this->now;
                
                // Update the session in the DB if needed
                if ($this->use_database === TRUE)
                {               
                        $this->CI->db->query($this->CI->db->update_string($this->session_table, array('last_activity' => $this->now, 'session_id' => $new_sessid), array('session_id' => $old_sessid)));
                }
                
                // Write the cookie
                $this->sess_write();
        }

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CI_Session::sess_write

(

)

Write the session cookie.

public

Returns:

void

Definition at line 294 of file Session.php.

References userdata().

Referenced by sess_create(), sess_update(), set_userdata(), and unset_userdata().

        {                                                               
                $cookie_data = serialize($this->userdata);
                
                if ($this->encryption == TRUE)
                {
                        $cookie_data = $this->CI->encrypt->encode($cookie_data);
                }
                else
                {
                        // if encryption is not used, we provide an md5 hash to prevent userside tampering
                        $cookie_data = $cookie_data . md5($cookie_data.$this->CI->config->item('encryption_key'));
                }

                setcookie(
                                        $this->sess_cookie,
                                        $cookie_data,
                                        $this->sess_length + time(),
                                        $this->CI->config->item('cookie_path'),
                                        $this->CI->config->item('cookie_domain'),
                                        0
                                );
        }

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CI_Session::set_flashdata	(	$	newdata = array(),
		$	newval = ''
	)

Add or change flashdata, only available until the next request.

public

Parameters:

	mixed
	string

Returns:

void

Definition at line 550 of file Session.php.

References $flashdata_key, and set_userdata().

    {
        if (is_string($newdata))
        {
            $newdata = array($newdata => $newval);
        }
        
        if (count($newdata) > 0)
        {
            foreach ($newdata as $key => $val)
            {
                $flashdata_key = $this->flashdata_key.':new:'.$key;
                $this->set_userdata($flashdata_key, $val);
            }
        }
    } 

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CI_Session::set_userdata	(	$	newdata = array(),
		$	newval = ''
	)

Add or change data in the "userdata" array.

public

Parameters:

	mixed
	string

Returns:

void

Definition at line 468 of file Session.php.

References sess_write(), and userdata().

Referenced by _flashdata_mark(), keep_flashdata(), and set_flashdata().

        {
                if (is_string($newdata))
                {
                        $newdata = array($newdata => $newval);
                }
        
                if (count($newdata) > 0)
                {
                        foreach ($newdata as $key => $val)
                        {
                                $this->userdata[$key] = $val;
                        }
                }

                $this->sess_write();
        }

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CI_Session::strip_slashes

(

$

vals

)

Strip slashes.

public

Parameters:

mixed

Returns:

mixed

Definition at line 521 of file Session.php.

Referenced by sess_read().

        {
                if (is_array($vals))
                {       
                        foreach ($vals as $key=>$val)
                        {
                                $vals[$key] = $this->strip_slashes($val);
                        }
                }
                else
                {
                        $vals = stripslashes($vals);
                }
                
                return $vals;
        }

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CI_Session::unset_userdata

(

$

newdata = array()

)

Delete a session variable from the "userdata" array.

array

Returns:

void

Definition at line 494 of file Session.php.

References sess_write(), and userdata().

Referenced by _flashdata_mark(), and _flashdata_sweep().

        {
                if (is_string($newdata))
                {
                        $newdata = array($newdata => '');
                }
        
                if (count($newdata) > 0)
                {
                        foreach ($newdata as $key => $val)
                        {
                                unset($this->userdata[$key]);
                        }
                }
        
                $this->sess_write();
        }

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CI_Session::userdata

(

$

item

)

Fetch a specific item from the session array.

public

Parameters:

string

Returns:

string

Definition at line 440 of file Session.php.

Referenced by all_userdata(), flashdata(), keep_flashdata(), sess_create(), sess_read(), sess_run(), sess_update(), sess_write(), set_userdata(), and unset_userdata().

        {
                return ( ! isset($this->userdata[$item])) ? FALSE : $this->userdata[$item];
        }

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Member Data Documentation

CI_Session::$CI

Definition at line 29 of file Session.php.

CI_Session::$encryption = TRUE

Definition at line 31 of file Session.php.

CI_Session::$flashdata_key = 'flash'

Definition at line 38 of file Session.php.

Referenced by flashdata(), and set_flashdata().

CI_Session::$gc_probability = 5

Definition at line 37 of file Session.php.

CI_Session::$now

Definition at line 30 of file Session.php.

Referenced by sess_run().

CI_Session::$sess_cookie = 'ci_session'

Definition at line 35 of file Session.php.

CI_Session::$sess_length = 7200

Definition at line 34 of file Session.php.

CI_Session::$session_table = FALSE

Definition at line 33 of file Session.php.

CI_Session::$time_to_update = 300

Definition at line 39 of file Session.php.

CI_Session::$use_database = FALSE

Definition at line 32 of file Session.php.

CI_Session::$userdata = array()

Definition at line 36 of file Session.php.

Referenced by _flashdata_mark(), and _flashdata_sweep().

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The documentation for this class was generated from the following file:

• Session.php