CDbStatePersister
| Package | system.base |
|---|---|
| Inheritance | class CDbStatePersister » CApplicationComponent » CComponent |
| Implements | IApplicationComponent, IStatePersister |
| Since | 1.1.17 |
| Source Code | framework/base/CDbStatePersister.php |
CDbStatePersister implements a database persistent data storage.
It can be used to keep data available through multiple requests and sessions.
By default, CDbStatePersister stores data in a table named 'state'. You may change the location by setting the stateTableName property.
To retrieve the data from CDbStatePersister, call load(). To save the data, call save().
Comparison among state persister, session and cache is as follows:
It can be used to keep data available through multiple requests and sessions.
By default, CDbStatePersister stores data in a table named 'state'. You may change the location by setting the stateTableName property.
To retrieve the data from CDbStatePersister, call load(). To save the data, call save().
Comparison among state persister, session and cache is as follows:
- session: data persisting within a single user session.
- state persister: data persisting through all requests/sessions (e.g. hit counter).
- cache: volatile and fast storage. It may be used as storage medium for session or state persister.
Public Properties
| Property | Type | Description | Defined By |
|---|---|---|---|
| behaviors | array | the behaviors that should be attached to this component. | CApplicationComponent |
| db | CDbConnection | instance | CDbStatePersister |
| dbComponent | string | connection ID | CDbStatePersister |
| isInitialized | boolean | Checks if this application component has been initialized. | CApplicationComponent |
| keyField | string | Column name for key-field | CDbStatePersister |
| stateTableName | string | the database table name storing the state data. | CDbStatePersister |
| valueField | string | Column name for value-field | CDbStatePersister |
Public Methods
| Method | Description | Defined By |
|---|---|---|
| __call() | Calls the named method which is not a class method. | CComponent |
| __get() | Returns a property value, an event handler list or a behavior based on its name. | CComponent |
| __isset() | Checks if a property value is null. | CComponent |
| __set() | Sets value of a component property. | CComponent |
| __unset() | Sets a component property to be null. | CComponent |
| asa() | Returns the named behavior object. | CComponent |
| attachBehavior() | Attaches a behavior to this component. | CComponent |
| attachBehaviors() | Attaches a list of behaviors to the component. | CComponent |
| attachEventHandler() | Attaches an event handler to an event. | CComponent |
| canGetProperty() | Determines whether a property can be read. | CComponent |
| canSetProperty() | Determines whether a property can be set. | CComponent |
| detachBehavior() | Detaches a behavior from the component. | CComponent |
| detachBehaviors() | Detaches all behaviors from the component. | CComponent |
| detachEventHandler() | Detaches an existing event handler. | CComponent |
| disableBehavior() | Disables an attached behavior. | CComponent |
| disableBehaviors() | Disables all behaviors attached to this component. | CComponent |
| enableBehavior() | Enables an attached behavior. | CComponent |
| enableBehaviors() | Enables all behaviors attached to this component. | CComponent |
| evaluateExpression() | Evaluates a PHP expression or callback under the context of this component. | CComponent |
| exists() | CDbStatePersister | |
| getEventHandlers() | Returns the list of attached event handlers for an event. | CComponent |
| getIsInitialized() | Checks if this application component has been initialized. | CApplicationComponent |
| hasEvent() | Determines whether an event is defined. | CComponent |
| hasEventHandler() | Checks whether the named event has attached handlers. | CComponent |
| hasProperty() | Determines whether a property is defined. | CComponent |
| init() | Initializes the component. | CDbStatePersister |
| load() | Loads state data from persistent storage. | CDbStatePersister |
| raiseEvent() | Raises an event. | CComponent |
| save() | Saves application state in persistent storage. | CDbStatePersister |
Protected Methods
| Method | Description | Defined By |
|---|---|---|
| createTable() | Creates state persister table | CDbStatePersister |
Property Details
db property
public CDbConnection $db;
instance
dbComponent property
public string $dbComponent;
connection ID
keyField property
public string $keyField;
Column name for key-field
stateTableName property
public string $stateTableName;
the database table name storing the state data. Make sure the table exists or database user is granted to CREATE tables.
valueField property
public string $valueField;
Column name for value-field
Method Details
createTable() method
protected void createTable() |
Source Code: framework/base/CDbStatePersister.php#137 (show)
protected function createTable()
{
try
{
$command=$this->db->createCommand();
$command->createTable($this->stateTableName,array(
$this->keyField=>'string NOT NULL',
$this->valueField=>'text NOT NULL',
'PRIMARY KEY ('.$this->db->quoteColumnName($this->keyField).')'
));
}
catch (CDbException $e)
{
throw new CException(Yii::t('yii','Can\'t create state persister table. Check CREATE privilege for \'{db}\' connection user or create table manually with SQL: {sql}.',array('{db}'=>$this->dbComponent,'{sql}'=>$command->text ) ) );
}
}
Creates state persister table
exists() method
public mixed exists() | ||
| {return} | mixed | |
Source Code: framework/base/CDbStatePersister.php#123 (show)
public function exists()
{
$command=$this->db->createCommand();
$command=$command->select($this->keyField)->from($this->stateTableName);
$command=$command->where($this->db->quoteColumnName($this->keyField).'=:key',array(
':key'=>Yii::app()->name
));
return $command->queryScalar();
}
init() method
public void init() |
Source Code: framework/base/CDbStatePersister.php#64 (show)
public function init()
{
parent::init();
if($this->stateTableName===null)
throw new CException(Yii::t('yii', 'stateTableName param cannot be null.'));
$this->db=Yii::app()->getComponent($this->dbComponent);
if($this->db===null)
throw new CException(Yii::t('yii', '\'{db}\' component doesn\'t exist.',array(
'{db}'=>$this->dbComponent
)));
if(!($this->db instanceof CDbConnection))
throw new CException(Yii::t ('yii', '\'{db}\' component is not a valid CDbConnection instance.',array(
'{db}'=>$this->dbComponent
)));
if($this->db->schema->getTable($this->stateTableName,true)===null)
$this->createTable();
}
Initializes the component. This method overrides the parent implementation by making sure stateFile contains valid value.
load() method
public mixed load() | ||
| {return} | mixed | state data. Null if no state data available. |
Source Code: framework/base/CDbStatePersister.php#86 (show)
public function load()
{
$command=$this->db->createCommand();
$command=$command->select($this->valueField)->from($this->stateTableName);
$command=$command->where($this->db->quoteColumnName($this->keyField).'=:key',array(
':key'=>Yii::app()->name
));
$state=$command->queryScalar();
if(false!==$state)
return unserialize($state);
else
return null;
}
Loads state data from persistent storage.
save() method
public int save(mixed $state) | ||
| $state | mixed | state data (must be serializable). |
| {return} | int | |
Source Code: framework/base/CDbStatePersister.php#105 (show)
public function save($state)
{
$command=$this->db->createCommand();
if(false===$this->exists())
return $command->insert($this->stateTableName,array(
$this->keyField=>Yii::app()->name,
$this->valueField=>serialize($state)
));
else
return $command->update($this->stateTableName,array($this->valueField=>serialize($state)),
$this->db->quoteColumnName($this->keyField).'=:key',
array(':key'=>Yii::app()->name)
);
}
Saves application state in persistent storage.
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Licensed under the three clause BSD license.
http://www.yiiframework.com/doc/api/1.1/CDbStatePersister