MultiFieldSession

API reference › yii › web › MultiFieldSession

abstract class	`yii\web\MultiFieldSession`
Extends	`Session` » `yii\base\Component` » `yii\base\BaseObject`
Implements	`yii\base\Configurable`, `IteratorAggregate`, `ArrayAccess`, `Countable`
Since	2.0.6
Source	`framework/web/MultiFieldSession.php`

1 subclass

DbSession

MultiFieldSession is the base class for session storage implementations with multi-field data storage support.

With multi-field data storage, session data can be split between several fields in the storage record. Using such a storage allows saving particular session data into separated field, which then can be used to manipulate sessions in the way plain PHP does not allow.

For example the ID of the authenticated user can be saved as separated column in the MySQL ‘session’ table, which allows to query all active sessions for a particular user or terminate them at will.

Customizing of the session writing is performed via $writeCallback, reading via $readCallback.

While extending this class you should use composeFields() method - while writing the session data into the storage and extractData() - while reading session data from the storage.

Properties

Property	Type	Description	Defined by
`$allFlashes` read-only	`array`	Flash messages (key => message or key => [message1, message2]).	`Session`
`$behaviors` read-only	`array<yii\base\Behavior<static>>`	List of behaviors attached to this component.	`yii\base\Component`
`$cacheLimiter`	`string`	Current cache limiter.	`Session`
`$cookieParams`	`array`	The session cookie parameters.	`Session`
`$count` read-only	`int`	The number of session variables.	`Session`
`$flash` write-only	`string`	The key identifying the flash message.	`Session`
`$flashParam`	`string`	The name of the session variable that stores the flash message data. Default: `'__flash'`.	`Session`
`$gCProbability`	`float`	The probability (percentage) that the GC (garbage collection) process is started on every session initialization.	`Session`
`$handler`	`SessionHandlerInterface\|array`	An object implementing the SessionHandlerInterface or a configuration array. Default: `null`.	`Session`
`$hasSessionId`	`bool`	Whether the current request has sent the session ID.	`Session`
`$id`	`string`	The current session ID.	`Session`
`$isActive` read-only	`bool`	Whether the session has started.	`Session`
`$iterator` read-only	`SessionIterator`	An iterator for traversing the session variables.	`Session`
`$name`	`string`	The current session name.	`Session`
`$readCallback`	`callable`	A callback that will be called during session data reading. Default: `null`.	`MultiFieldSession`
`$savePath`	`string`	The current session save path, defaults to ‘/tmp’.	`Session`
`$timeout`	`int`	The number of seconds after which data will be seen as ‘garbage’ and cleaned up.	`Session`
`$useCookies`	`bool\|null`	The value indicating whether cookies should be used to store session IDs.	`Session`
`$useCustomStorage` read-only	`bool`	Whether to use custom storage.	`MultiFieldSession`
`$useStrictMode`	`bool`	Whether strict mode is enabled or not.	`Session`
`$useTransparentSessionID`	`bool`	Whether transparent sid support is enabled or not, defaults to false.	`Session`
`$writeCallback`	`callable\|null`	A callback that will be called during session data writing. Default: `null`.	`MultiFieldSession`
`$_forceRegenerateId` protected	`string\|null`	Holds the session id in case useStrictMode is enabled and the session id needs to be regenerated Default: `null`.	`Session`
`$_originalSessionModule` protected static	`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. Default: `null`.	`Session`

Methods

Method	Description	Defined by
`__construct()`	Constructor.	`yii\base\BaseObject`
`__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`
`__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.	`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()` static	Returns the fully qualified name of this class.	`yii\base\BaseObject`
`close()`	Ends the current session and store session data.	`Session`
`count()`	Returns the number of items in the session.	`Session`
`destroy()`	Frees all session variables and destroys all data registered to a session.	`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`
`get()`	Returns the session variable value with the session variable name.	`Session`
`getAllFlashes()`	Returns all flash messages.	`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	`Session`
`getCookieParams()`		`Session`
`getCount()`	Returns the number of items in the session.	`Session`
`getFlash()`	Returns a flash message.	`Session`
`getGCProbability()`		`Session`
`getHasSessionId()`	Returns a value indicating whether the current request has sent the session ID.	`Session`
`getId()`	Gets the session ID.	`Session`
`getIsActive()`		`Session`
`getIterator()`	Returns an iterator for traversing the session variables.	`Session`
`getName()`	Gets the name of the current session.	`Session`
`getSavePath()`	Gets the current session save path.	`Session`
`getTimeout()`		`Session`
`getUseCookies()`	Returns the value indicating whether cookies should be used to store session IDs.	`Session`
`getUseCustomStorage()`	Returns a value indicating whether to use custom session storage.	`MultiFieldSession`
`getUseStrictMode()`		`Session`
`getUseTransparentSessionID()`		`Session`
`has()`		`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.	`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 application component.	`Session`
`off()`	Detaches an existing event handler from this component.	`yii\base\Component`
`offsetExists()`	This method is required by the interface `ArrayAccess`.	`Session`
`offsetGet()`	This method is required by the interface `ArrayAccess`.	`Session`
`offsetSet()`	This method is required by the interface `ArrayAccess`.	`Session`
`offsetUnset()`	This method is required by the interface `ArrayAccess`.	`Session`
`on()`	Attaches an event handler to an event.	`yii\base\Component`
`open()`	Starts the session.	`Session`
`regenerateID()`	Updates the current session ID with a newly generated one.	`Session`
`remove()`	Removes a session variable.	`Session`
`removeAll()`	Removes all session variables.	`Session`
`removeAllFlashes()`	Removes all flash messages.	`Session`
`removeFlash()`	Removes a flash message.	`Session`
`set()`	Adds a session variable.	`Session`
`setCacheLimiter()`	Set cache limiter	`Session`
`setCookieParams()`	Sets the session cookie parameters.	`Session`
`setFlash()`	Sets a flash message.	`Session`
`setGCProbability()`		`Session`
`setHasSessionId()`	Sets the value indicating whether the current request has sent the session ID.	`Session`
`setId()`	Sets the session ID.	`Session`
`setName()`	Sets the name for the current session.	`Session`
`setSavePath()`	Sets the current session save path.	`Session`
`setTimeout()`		`Session`
`setUseCookies()`	Sets the value indicating whether cookies should be used to store session IDs.	`Session`
`setUseStrictMode()`		`Session`
`setUseTransparentSessionID()`		`Session`
`trigger()`	Triggers an event.	`yii\base\Component`
`composeFields()` protected	Composes storage field set for session writing.	`MultiFieldSession`
`extractData()` protected	Extracts session data from storage field set.	`MultiFieldSession`
`freeze()` protected	If session is started it’s not possible to edit session ini settings. In PHP7.2+ it throws exception.	`Session`
`registerSessionHandler()` protected	Registers session handler.	`Session`
`unfreeze()` protected	Starts session and restores data from temporary variable	`Session`
`updateFlashCounters()` protected	Updates the counters for flash messages and removes outdated flash messages.	`Session`

Property details

$readCallback

public callable $readCallback = null

A callback that will be called during session data reading.

The signature of the callback should be as follows:

function ($fields)

where $fields is the storage field set for read session and $session is this session instance. If callback returns an array, it will be merged into the session data.

For example:

function ($fields) {
    return [
        'expireDate' => Yii::$app->formatter->asDate($fields['expire']),
    ];
}

$writeCallback

public callable|null $writeCallback = null

A callback that will be called during session data writing.

The signature of the callback should be as follows:

function ($session)

where $session is this session instance, this variable can be used to retrieve session data. Callback should return the actual fields set, which should be saved into the session storage.

For example:

function ($session) {
    return [
        'user_id' => Yii::$app->user->id,
        'ip' => $_SERVER['REMOTE_ADDR'],
        'is_trusted' => $session->get('is_trusted', false),
    ];
}

Method details

getUseCustomStorage()

public function getUseCustomStorage(): bool

Returns a value indicating whether to use custom session storage.

This method overrides the parent implementation and always returns true.

Returns

bool: Whether to use custom storage.

composeFields()

protected function composeFields(string|null $id = null, string|null $data = null): array

Composes storage field set for session writing.

Parameters

Parameter	Type	Description
`$id`	`string\|null`	Optional session id
`$data`	`string\|null`	Optional session data

Returns

array: Storage fields

extractData()

protected function extractData(array $fields): string

Extracts session data from storage field set.

Parameters

Parameter	Type	Description
`$fields`	`array`	Storage fields.

Returns

string: Session data.