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Class yii\behaviors\OptimisticLockBehavior

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Inheritanceyii\behaviors\OptimisticLockBehavior » yii\behaviors\AttributeBehavior » yii\base\Behavior » yii\base\BaseObject
Implementsyii\base\Configurable
Available since version2.0.16
Source Code https://github.com/yiisoft/yii2/blob/master/framework/behaviors/OptimisticLockBehavior.php

OptimisticLockBehavior automatically upgrades a model's lock version using the column name returned by optimisticLock().

Optimistic locking allows multiple users to access the same record for edits and avoids potential conflicts. In case when a user attempts to save the record upon some staled data (because another user has modified the data), a StaleObjectException exception will be thrown, and the update or deletion is skipped.

To use this behavior, first enable optimistic lock by following the steps listed in optimisticLock(), remove the column name holding the lock version from the rules() method of your ActiveRecord class, then add the following code to it:

use yii\behaviors\OptimisticLockBehavior;

public function behaviors()
{
    return [
        OptimisticLockBehavior::class,
    ];
}

By default, OptimisticLockBehavior will use getBodyParam() to parse the submitted value or set it to 0 on any fail. That means a request not holding the version attribute may achieve a first successful update to entity, but starting from there any further try should fail unless the request is holding the expected version number.

Once attached, internal use of the model class should also fail to save the record if the version number isn't held by getBodyParam(). It may be useful to extend your model class, enable optimistic lock in parent class by overriding optimisticLock(), then attach the behavior to the child class so you can tie the parent model to internal use while linking the child model holding this behavior to the controllers responsible of receiving end user inputs. Alternatively, you can also configure the $value property with a PHP callable to implement a different logic.

OptimisticLockBehavior also provides a method named upgrade() that increases a model's version by one, that may be useful when you need to mark an entity as stale among connected clients and avoid any change to it until they load it again:

$model->upgrade();

See also yii\db\BaseActiveRecord::optimisticLock() for details on how to enable optimistic lock.

Public Properties

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Property Type Description Defined By
$attributes array List of attributes that are to be automatically filled with the value specified via $value. yii\behaviors\AttributeBehavior
$owner yii\base\Component|null The owner of this behavior yii\base\Behavior
$preserveNonEmptyValues boolean Whether to preserve non-empty attribute values. yii\behaviors\AttributeBehavior
$skipUpdateOnClean boolean Whether to skip this behavior when the $owner has not been modified yii\behaviors\OptimisticLockBehavior
$value mixed The value that will be assigned to the current attributes. yii\behaviors\OptimisticLockBehavior

Public Methods

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Method Description Defined By
__call() Calls the named method which is not a class method. yii\base\BaseObject
__construct() Constructor. yii\base\BaseObject
__get() Returns the value of an object property. yii\base\BaseObject
__isset() Checks if a property is set, i.e. defined and not null. yii\base\BaseObject
__set() Sets value of an object property. yii\base\BaseObject
__unset() Sets an object property to null. yii\base\BaseObject
attach() Attaches the behavior object to the component. yii\behaviors\OptimisticLockBehavior
canGetProperty() Returns a value indicating whether a property can be read. yii\base\BaseObject
canSetProperty() Returns a value indicating whether a property can be set. yii\base\BaseObject
className() Returns the fully qualified name of this class. yii\base\BaseObject
detach() Detaches the behavior object from the component. yii\base\Behavior
evaluateAttributes() Evaluates the attribute value and assigns it to the current attributes. yii\behaviors\AttributeBehavior
events() Declares event handlers for the $owner's events. yii\behaviors\OptimisticLockBehavior
hasMethod() Returns a value indicating whether a method is defined. yii\base\BaseObject
hasProperty() Returns a value indicating whether a property is defined. yii\base\BaseObject
init() Initializes the object. yii\base\BaseObject
upgrade() Upgrades the version value by one and stores it to database. yii\behaviors\OptimisticLockBehavior

Protected Methods

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Method Description Defined By
getLockAttribute() Returns the column name to hold the version value as defined in optimisticLock(). yii\behaviors\OptimisticLockBehavior
getValue() Returns the value for the current attributes. yii\behaviors\OptimisticLockBehavior

Property Details

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$skipUpdateOnClean public property (available since version 2.0.8)

Whether to skip this behavior when the $owner has not been modified

public boolean $skipUpdateOnClean = false
$value public property

In case of null value it will be directly parsed from getBodyParam() or set to 0.

The value that will be assigned to the current attributes. This can be an anonymous function, callable in array format (e.g. [$this, 'methodName']), an Expression object representing a DB expression (e.g. new Expression('NOW()')), scalar, string or an arbitrary value. If the former, the return value of the function will be assigned to the attributes. The signature of the function should be as follows,

function ($event)
{
    // return value will be assigned to the attribute
}
public mixed $value = null

Method Details

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__call() public method

Defined in: yii\base\BaseObject::__call()

Calls the named method which is not a class method.

Do not call this method directly as it is a PHP magic method that will be implicitly called when an unknown method is being invoked.

public mixed __call ( $name, $params )
$name string

The method name
$params array

Method parameters
return mixed

The method return value
throws yii\base\UnknownMethodException

when calling unknown method

 

                public function __call($name, $params)
{
    throw new UnknownMethodException('Calling unknown method: ' . get_class($this) . "::$name()");
}
__construct() public method

Defined in: yii\base\BaseObject::__construct()

Constructor.

The default implementation does two things:

  • Initializes the object with the given configuration $config.
  • Call init().

If this method is overridden in a child class, it is recommended that

  • the last parameter of the constructor is a configuration array, like $config here.
  • call the parent implementation at the end of the constructor.
public void __construct ( $config = [] )
$config array

Name-value pairs that will be used to initialize the object properties

 

                public function __construct($config = [])
{
    if (!empty($config)) {
        Yii::configure($this, $config);
    }
    $this->init();
}
__get() public method

Defined in: yii\base\BaseObject::__get()

Returns the value of an object property.

Do not call this method directly as it is a PHP magic method that will be implicitly called when executing $value = $object->property;.

See also __set().

public mixed __get ( $name )
$name string

The property name
return mixed

The property value
throws yii\base\UnknownPropertyException

if the property is not defined
throws yii\base\InvalidCallException

if the property is write-only

 

                public function __get($name)
{
    $getter = 'get' . $name;
    if (method_exists($this, $getter)) {
        return $this->$getter();
    } elseif (method_exists($this, 'set' . $name)) {
        throw new InvalidCallException('Getting write-only property: ' . get_class($this) . '::' . $name);
    }
    throw new UnknownPropertyException('Getting unknown property: ' . get_class($this) . '::' . $name);
}
__isset() public method

Defined in: yii\base\BaseObject::__isset()

Checks if a property is set, i.e. defined and not null.

Do not call this method directly as it is a PHP magic method that will be implicitly called when executing isset($object->property).

Note that if the property is not defined, false will be returned.

See also https://www.php.net/manual/en/function.isset.php.

public boolean __isset ( $name )
$name string

The property name or the event name
return boolean

Whether the named property is set (not null).

 

                public function __isset($name)
{
    $getter = 'get' . $name;
    if (method_exists($this, $getter)) {
        return $this->$getter() !== null;
    }
    return false;
}
__set() public method

Defined in: yii\base\BaseObject::__set()

Sets value of an object property.

Do not call this method directly as it is a PHP magic method that will be implicitly called when executing $object->property = $value;.

See also __get().

public void __set ( $name, $value )
$name string

The property name or the event name
$value mixed

The property value
throws yii\base\UnknownPropertyException

if the property is not defined
throws yii\base\InvalidCallException

if the property is read-only

 

                public function __set($name, $value)
{
    $setter = 'set' . $name;
    if (method_exists($this, $setter)) {
        $this->$setter($value);
    } elseif (method_exists($this, 'get' . $name)) {
        throw new InvalidCallException('Setting read-only property: ' . get_class($this) . '::' . $name);
    } else {
        throw new UnknownPropertyException('Setting unknown property: ' . get_class($this) . '::' . $name);
    }
}
__unset() public method

Defined in: yii\base\BaseObject::__unset()

Sets an object property to null.

Do not call this method directly as it is a PHP magic method that will be implicitly called when executing unset($object->property).

Note that if the property is not defined, this method will do nothing. If the property is read-only, it will throw an exception.

See also https://www.php.net/manual/en/function.unset.php.

public void __unset ( $name )
$name string

The property name
throws yii\base\InvalidCallException

if the property is read only.

 

                public function __unset($name)
{
    $setter = 'set' . $name;
    if (method_exists($this, $setter)) {
        $this->$setter(null);
    } elseif (method_exists($this, 'get' . $name)) {
        throw new InvalidCallException('Unsetting read-only property: ' . get_class($this) . '::' . $name);
    }
}
attach() public method

Attaches the behavior object to the component.

The default implementation will set the $owner property and attach event handlers as declared in events(). Make sure you call the parent implementation if you override this method.

public void attach ( $owner )
$owner yii\base\Component

The component that this behavior is to be attached to.

 

                public function attach($owner)
{
    parent::attach($owner);
    if (empty($this->attributes)) {
        $lock = $this->getLockAttribute();
        $this->attributes = array_fill_keys(array_keys($this->events()), $lock);
    }
}
canGetProperty() public method

Defined in: yii\base\BaseObject::canGetProperty()

Returns a value indicating whether a property can be read.

A property is readable if:

  • the class has a getter method associated with the specified name (in this case, property name is case-insensitive);
  • the class has a member variable with the specified name (when $checkVars is true);

See also canSetProperty().

public boolean canGetProperty ( $name, $checkVars = true )
$name string

The property name
$checkVars boolean

Whether to treat member variables as properties
return boolean

Whether the property can be read

 

                public function canGetProperty($name, $checkVars = true)
{
    return method_exists($this, 'get' . $name) || $checkVars && property_exists($this, $name);
}
canSetProperty() public method

Defined in: yii\base\BaseObject::canSetProperty()

Returns a value indicating whether a property can be set.

A property is writable if:

  • the class has a setter method associated with the specified name (in this case, property name is case-insensitive);
  • the class has a member variable with the specified name (when $checkVars is true);

See also canGetProperty().

public boolean canSetProperty ( $name, $checkVars = true )
$name string

The property name
$checkVars boolean

Whether to treat member variables as properties
return boolean

Whether the property can be written

 

                public function canSetProperty($name, $checkVars = true)
{
    return method_exists($this, 'set' . $name) || $checkVars && property_exists($this, $name);
}
className() public static method
Deprecated since 2.0.14. On PHP >=5.5, use ::class instead.

Defined in: yii\base\BaseObject::className()

Returns the fully qualified name of this class.

public static string className ( )
return string

The fully qualified name of this class.

 

                public static function className()
{
    return get_called_class();
}
detach() public method

Defined in: yii\base\Behavior::detach()

Detaches the behavior object from the component.

The default implementation will unset the $owner property and detach event handlers declared in events(). Make sure you call the parent implementation if you override this method.

public void detach ( )

                public function detach()
{
    if ($this->owner) {
        foreach ($this->_attachedEvents as $event => $handler) {
            $this->owner->off($event, is_string($handler) ? [$this, $handler] : $handler);
        }
        $this->_attachedEvents = [];
        $this->owner = null;
    }
}
evaluateAttributes() public method

Defined in: yii\behaviors\AttributeBehavior::evaluateAttributes()

Evaluates the attribute value and assigns it to the current attributes.

public void evaluateAttributes ( $event )
$event yii\base\Event 

                public function evaluateAttributes($event)
{
    if (
        $this->skipUpdateOnClean
        && $event->name == ActiveRecord::EVENT_BEFORE_UPDATE
        && empty($this->owner->dirtyAttributes)
    ) {
        return;
    }
    if (!empty($this->attributes[$event->name])) {
        $attributes = (array) $this->attributes[$event->name];
        $value = $this->getValue($event);
        foreach ($attributes as $attribute) {
            // ignore attribute names which are not string (e.g. when set by TimestampBehavior::updatedAtAttribute)
            if (is_string($attribute)) {
                if ($this->preserveNonEmptyValues && !empty($this->owner->$attribute)) {
                    continue;
                }
                $this->owner->$attribute = $value;
            }
        }
    }
}
events() public method

Declares event handlers for the $owner's events.

Child classes may override this method to declare what PHP callbacks should be attached to the events of the $owner component.

The callbacks will be attached to the $owner's events when the behavior is attached to the owner; and they will be detached from the events when the behavior is detached from the component.

The callbacks can be any of the following:

  • method in this behavior: 'handleClick', equivalent to [$this, 'handleClick']
  • object method: [$object, 'handleClick']
  • static method: ['Page', 'handleClick']
  • anonymous function: function ($event) { ... }

The following is an example:

[
    Model::EVENT_BEFORE_VALIDATE => 'myBeforeValidate',
    Model::EVENT_AFTER_VALIDATE => 'myAfterValidate',
]
public array events ( )
return array

Events (array keys) and the corresponding event handler methods (array values).

 

                public function events()
{
    return Yii::$app->request instanceof \yii\web\Request ? [
        BaseActiveRecord::EVENT_BEFORE_INSERT => 'evaluateAttributes',
        BaseActiveRecord::EVENT_BEFORE_UPDATE => 'evaluateAttributes',
        BaseActiveRecord::EVENT_BEFORE_DELETE => 'evaluateAttributes',
    ] : [];
}
getLockAttribute() protected method (available since version 2.0.16)

Returns the column name to hold the version value as defined in optimisticLock().

protected string getLockAttribute ( )
return string

The property name.
throws yii\base\InvalidCallException

if optimisticLock() is not properly configured.

 

                protected function getLockAttribute()
{
    if ($this->_lockAttribute) {
        return $this->_lockAttribute;
    }
    /* @var $owner BaseActiveRecord */
    $owner = $this->owner;
    $lock = $owner->optimisticLock();
    if ($lock === null || $owner->hasAttribute($lock) === false) {
        throw new InvalidCallException("Unable to get the optimistic lock attribute. Probably 'optimisticLock()' method is misconfigured.");
    }
    $this->_lockAttribute = $lock;
    return $lock;
}
getValue() protected method

Returns the value for the current attributes.

In case of null, value will be parsed from getBodyParam() or set to 0.

This method is called by evaluateAttributes(). Its return value will be assigned to the attributes corresponding to the triggering event.

protected mixed getValue ( $event )
$event yii\base\Event

The event that triggers the current attribute updating.
return mixed

The attribute value

 

                protected function getValue($event)
{
    if ($this->value === null) {
        $request = Yii::$app->getRequest();
        $lock = $this->getLockAttribute();
        $formName = $this->owner->formName();
        $formValue = $formName ? ArrayHelper::getValue($request->getBodyParams(), $formName . '.' . $lock) : null;
        $input = $formValue ?: $request->getBodyParam($lock);
        $isValid = $input && (new NumberValidator())->validate($input);
        return $isValid ? $input : 0;
    }
    return parent::getValue($event);
}
hasMethod() public method

Defined in: yii\base\BaseObject::hasMethod()

Returns a value indicating whether a method is defined.

The default implementation is a call to php function method_exists(). You may override this method when you implemented the php magic method __call().

public boolean hasMethod ( $name )
$name string

The method name
return boolean

Whether the method is defined

 

                public function hasMethod($name)
{
    return method_exists($this, $name);
}
hasProperty() public method

Defined in: yii\base\BaseObject::hasProperty()

Returns a value indicating whether a property is defined.

A property is defined if:

  • the class has a getter or setter method associated with the specified name (in this case, property name is case-insensitive);
  • the class has a member variable with the specified name (when $checkVars is true);

See also:

public boolean hasProperty ( $name, $checkVars = true )
$name string

The property name
$checkVars boolean

Whether to treat member variables as properties
return boolean

Whether the property is defined

 

                public function hasProperty($name, $checkVars = true)
{
    return $this->canGetProperty($name, $checkVars) || $this->canSetProperty($name, false);
}
init() public method

Defined in: yii\base\BaseObject::init()

Initializes the object.

This method is invoked at the end of the constructor after the object is initialized with the given configuration.

public void init ( )

                public function init()
{
}
upgrade() public method (available since version 2.0.16)

Upgrades the version value by one and stores it to database.

$model->upgrade();
public void upgrade ( )
throws yii\base\InvalidCallException

if owner is a new record.

 

                public function upgrade()
{
    /* @var $owner BaseActiveRecord */
    $owner = $this->owner;
    if ($owner->getIsNewRecord()) {
        throw new InvalidCallException('Upgrading the model version is not possible on a new record.');
    }
    $lock = $this->getLockAttribute();
    $version = $owner->$lock ?: 0;
    $owner->updateAttributes([$lock => $version + 1]);
}