# Class yii\mongodb\Session

Inheritance | yii\mongodb\Session » yii\web\MultiFieldSession » yii\web\Session » yii\base\Component » yii\base\BaseObject
Implements | ArrayAccess, Countable, IteratorAggregate, yii\base\Configurable
Available since version | 2.0
Source Code | https://github.com/yiisoft/yii2-mongodb/blob/master/Session.php

Session extends yii\web\Session by using MongoDB as session data storage.

By default, Session stores session data in a collection named 'session' inside the default database. This collection is better to be pre-created with fields 'id' and 'expire' indexed. The collection name can be changed by setting $sessionCollection.

The following example shows how you can configure the application to use Session: Add the following to your application config under `components`:

    'session' => [
        'class' => 'yii\mongodb\Session',
        // 'db' => 'mymongodb',
        // 'sessionCollection' => 'my_session',
    ]

Session extends yii\web\MultiFieldSession, thus it allows saving extra fields into the $sessionCollection. Refer to yii\web\MultiFieldSession for more details.

Tip: you can use MongoDB TTL index for the session garbage collection for performance saving, in this case you should set yii\mongodb\Session::$gCProbability to `0`.

## Public Properties

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Property | Type | Description | Defined By
--- | --- | --- | ---
$allFlashes | array | Flash messages (key => message or key => [message1, message2]). This property is read-only. | yii\web\Session
$behaviors | yii\base\Behavior[] | List of behaviors attached to this component. This property is read-only. | yii\base\Component
$cacheLimiter | string | Current cache limiter. This property is read-only. | yii\web\Session
$cookieParams | array | The session cookie parameters. This property is read-only. | yii\web\Session
$count | integer | The number of session variables. This property is read-only. | yii\web\Session
$db | yii\mongodb\Connection|array|string | The MongoDB connection object or the application component ID of the MongoDB connection. | yii\mongodb\Session
$flash | string | The key identifying the flash message. Note that flash messages and normal session variables share the same name space. If you have a normal session variable using the same name, its value will be overwritten by this method. This property is write-only. | yii\web\Session
$flashParam | string | The name of the session variable that stores the flash message data. | yii\web\Session
$gCProbability | float | The probability (percentage) that the GC (garbage collection) process is started on every session initialization. | yii\web\Session
$handler | SessionHandlerInterface|array | An object implementing the SessionHandlerInterface or a configuration array. | yii\web\Session
$hasSessionId | boolean | Whether the current request has sent the session ID. | yii\web\Session
$id | string | The current session ID. | yii\web\Session
$isActive | boolean | Whether the session has started. This property is read-only. | yii\web\Session
$iterator | yii\web\SessionIterator | An iterator for traversing the session variables. This property is read-only. | yii\web\Session
$name | string | The current session name. | yii\web\Session
$readCallback | callable | A callback that will be called during session data reading. | yii\web\MultiFieldSession
$savePath | string | The current session save path, defaults to '/tmp'. | yii\web\Session
$sessionCollection | string|array | The name of the MongoDB collection that stores the session data. | yii\mongodb\Session
$timeout | integer | The number of seconds after which data will be seen as 'garbage' and cleaned up. The default value is 1440 seconds (or the value of "session.gc_maxlifetime" set in php.ini). | yii\web\Session
$useCookies | boolean|null | The value indicating whether cookies should be used to store session IDs. | yii\web\Session
$useCustomStorage | boolean | Whether to use custom storage. This property is read-only. | yii\web\MultiFieldSession
$useStrictMode | boolean | Whether strict mode is enabled or not. This property is read-only. | yii\web\Session
$useTransparentSessionID | boolean | Whether transparent sid support is enabled or not, defaults to false. | yii\web\Session
$writeCallback | callable | A callback that will be called during session data writing. | yii\web\MultiFieldSession

## Protected Properties

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Property | Type | Description | Defined By
--- | --- | --- | ---
$_forceRegenerateId | string|null | Holds the session id in case useStrictMode is enabled and the session id needs to be regenerated | yii\web\Session
$_originalSessionModule | string|null | Holds the original session module (before a custom handler is registered) so that it can be restored when a Session component without custom handler is used after one that has. | yii\web\Session
$fields | array | Session fields to be written into session table columns | yii\mongodb\Session

## Public Methods

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Method | Description | Defined By
--- | --- | ---
__call() | Calls the named method which is not a class method. | yii\base\Component
__clone() | This method is called after the object is created by cloning an existing one. | yii\base\Component
__construct() | Constructor. | yii\base\BaseObject
__get() | Returns the value of a component property. | yii\base\Component
__isset() | Checks if a property is set, i.e. defined and not null. | yii\base\Component
__set() | Sets the value of a component property. | yii\base\Component
__unset() | Sets a component property to be null. | yii\base\Component
addFlash() | Adds a flash message. | yii\web\Session
attachBehavior() | Attaches a behavior to this component. | yii\base\Component
attachBehaviors() | Attaches a list of behaviors to the component. | yii\base\Component
behaviors() | Returns a list of behaviors that this component should behave as. | yii\base\Component
canGetProperty() | Returns a value indicating whether a property can be read. | yii\base\Component
canSetProperty() | Returns a value indicating whether a property can be set. | yii\base\Component
className() | Returns the fully qualified name of this class. | yii\base\BaseObject
close() | Ends the current session and store session data. | yii\web\Session
closeSession() | Session close handler. | yii\web\Session
count() | Returns the number of items in the session. | yii\web\Session
destroy() | Frees all session variables and destroys all data registered to a session. | yii\web\Session
destroySession() | Session destroy handler. | yii\mongodb\Session
detachBehavior() | Detaches a behavior from the component. | yii\base\Component
detachBehaviors() | Detaches all behaviors from the component. | yii\base\Component
ensureBehaviors() | Makes sure that the behaviors declared in behaviors() are attached to this component. | yii\base\Component
gcSession() | Session GC (garbage collection) handler. | yii\mongodb\Session
get() | Returns the session variable value with the session variable name. | yii\web\Session
getAllFlashes() | Returns all flash messages. | yii\web\Session
getBehavior() | Returns the named behavior object. | yii\base\Component
getBehaviors() | Returns all behaviors attached to this component. | yii\base\Component
getCacheLimiter() | Returns current cache limiter | yii\web\Session
getCookieParams() |  | yii\web\Session
getCount() | Returns the number of items in the session. | yii\web\Session
getFlash() | Returns a flash message. | yii\web\Session
getGCProbability() |  | yii\web\Session
getHasSessionId() | Returns a value indicating whether the current request has sent the session ID. | yii\web\Session
getId() | Gets the session ID. | yii\web\Session
getIsActive() |  | yii\web\Session
getIterator() | Returns an iterator for traversing the session variables. | yii\web\Session
getName() | Gets the name of the current session. | yii\web\Session
getSavePath() | Gets the current session save path. | yii\web\Session
getTimeout() |  | yii\web\Session
getUseCookies() | Returns the value indicating whether cookies should be used to store session IDs. | yii\web\Session
getUseCustomStorage() | Returns a value indicating whether to use custom session storage. | yii\web\MultiFieldSession
getUseStrictMode() |  | yii\web\Session
getUseTransparentSessionID() |  | yii\web\Session
has() |  | yii\web\Session
hasEventHandlers() | Returns a value indicating whether there is any handler attached to the named event. | yii\base\Component
hasFlash() | Returns a value indicating whether there are flash messages associated with the specified key. | yii\web\Session
hasMethod() | Returns a value indicating whether a method is defined. | yii\base\Component
hasProperty() | Returns a value indicating whether a property is defined for this component. | yii\base\Component
init() | Initializes the Session component. | yii\mongodb\Session
off() | Detaches an existing event handler from this component. | yii\base\Component
offsetExists() | This method is required by the interface ArrayAccess. | yii\web\Session
offsetGet() | This method is required by the interface ArrayAccess. | yii\web\Session
offsetSet() | This method is required by the interface ArrayAccess. | yii\web\Session
offsetUnset() | This method is required by the interface ArrayAccess. | yii\web\Session
on() | Attaches an event handler to an event. | yii\base\Component
open() | Starts the session. | yii\web\Session
openSession() | Session open handler. | yii\mongodb\Session
readSession() | Session read handler. | yii\mongodb\Session
regenerateID() | Updates the current session ID with a newly generated one. | yii\mongodb\Session
remove() | Removes a session variable. | yii\web\Session
removeAll() | Removes all session variables. | yii\web\Session
removeAllFlashes() | Removes all flash messages. | yii\web\Session
removeFlash() | Removes a flash message. | yii\web\Session
set() | Adds a session variable. | yii\web\Session
setCacheLimiter() | Set cache limiter | yii\web\Session
setCookieParams() | Sets the session cookie parameters. | yii\web\Session
setFlash() | Sets a flash message. | yii\web\Session
setGCProbability() |  | yii\web\Session
setHasSessionId() | Sets the value indicating whether the current request has sent the session ID. | yii\web\Session
setId() | Sets the session ID. | yii\web\Session
setName() | Sets the name for the current session. | yii\web\Session
setSavePath() | Sets the current session save path. | yii\web\Session
setTimeout() |  | yii\web\Session
setUseCookies() | Sets the value indicating whether cookies should be used to store session IDs. | yii\web\Session
setUseStrictMode() |  | yii\web\Session
setUseTransparentSessionID() |  | yii\web\Session
trigger() | Triggers an event. | yii\base\Component
writeSession() | Session write handler. | yii\mongodb\Session

## Protected Methods

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Method | Description | Defined By
--- | --- | ---
composeFields() | Composes storage field set for session writing. | yii\web\MultiFieldSession
extractData() | Extracts session data from storage field set. | yii\web\MultiFieldSession
freeze() | If session is started it's not possible to edit session ini settings. In PHP7.2+ it throws exception. | yii\web\Session
registerSessionHandler() | Registers session handler. | yii\web\Session
unfreeze() | Starts session and restores data from temporary variable | yii\web\Session
updateFlashCounters() | Updates the counters for flash messages and removes outdated flash messages. | yii\web\Session

## Property Details

$db public property

The MongoDB connection object or the application component ID of the MongoDB connection. After the Session object is created, if you want to change this property, you should only assign it with a MongoDB connection object. Starting from version 2.0.2, this can also be a configuration array for creating the object.

public yii\mongodb\Connection|array|string $db = 'mongodb'
$fields protected property (available since version 2.1.8)

Session fields to be written into session table columns

protected array $fields = []
$sessionCollection public property

The name of the MongoDB collection that stores the session data. Please refer to yii\mongodb\Connection::getCollection() on how to specify this parameter. This collection is better to be pre-created with fields 'id' and 'expire' indexed.

public string|array $sessionCollection = 'session'

## Method Details

destroySession() public method

Session destroy handler.

Do not call this method directly.

public boolean destroySession ( $id )
$id | string | Session ID
return | boolean | Whether session is destroyed successfully

gcSession() public method

Session GC (garbage collection) handler.

Do not call this method directly.

public boolean gcSession ( $maxLifetime )
$maxLifetime | integer | The number of seconds after which data will be seen as 'garbage' and cleaned up.
return | boolean | Whether session is GCed successfully

init() public method

Initializes the Session component.

This method will initialize the $db property to make sure it refers to a valid MongoDB connection.

public void init ( )
throws | yii\base\InvalidConfigException | if $db is invalid.

openSession() public method

Session open handler.

public boolean openSession ( $savePath, $sessionName )
$savePath | string | Session save path
$sessionName | string | Session name
return | boolean | Whether session is opened successfully

readSession() public method

Session read handler.

Do not call this method directly.

public string readSession ( $id )
$id | string | Session ID
return | string | The session data

regenerateID() public method

Updates the current session ID with a newly generated one.

Please refer to http://php.net/session_regenerate_id for more details.

public void regenerateID ( $deleteOldSession = false )
$deleteOldSession | boolean | Whether to delete the old associated session file or not.

writeSession() public method

Session write handler.

Do not call this method directly.

public boolean writeSession ( $id, $data )
$id | string | Session ID
$data | string | Session data
return | boolean | Whether session write is successful