CHttpCacheFilter
| 包 | system.web.filters |
|---|---|
| 继承 | class CHttpCacheFilter » CFilter » CComponent |
| 实现 | IFilter |
| 可用自 | 1.1.11 |
| 源码 | framework/web/filters/CHttpCacheFilter.php |
CHttpCacheFilter implements http caching. It works a lot like COutputCache
as a filter, except that content caching is being done on the client side.
公共属性
| 属性 | 类型 | 描述 | 被定义在 |
|---|---|---|---|
| cacheControl | string | Http cache control headers. | CHttpCacheFilter |
| etagSeed | mixed | Seed for the ETag. | CHttpCacheFilter |
| etagSeedExpression | string|callback | Expression for the ETag seed. | CHttpCacheFilter |
| lastModified | string|integer | Timestamp for the last modification date. | CHttpCacheFilter |
| lastModifiedExpression | string|callback | PHP Expression for the last modification date. | CHttpCacheFilter |
受保护的属性
| 属性 | 类型 | 描述 | 被定义在 |
|---|---|---|---|
| etagValue | string|boolean | Gets the ETag out of either etagSeedExpression or etagSeed | CHttpCacheFilter |
| lastModifiedValue | integer|boolean | Gets the last modified value from either lastModifiedExpression or lastModified | CHttpCacheFilter |
公共方法
| 方法 | 描述 | 被定义在 |
|---|---|---|
| __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 |
| filter() | Performs the filtering. | CFilter |
| getEventHandlers() | Returns the list of attached event handlers for an event. | CComponent |
| 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 filter. | CFilter |
| preFilter() | Performs the pre-action filtering. | CHttpCacheFilter |
| raiseEvent() | Raises an event. | CComponent |
受保护的方法
| 方法 | 描述 | 被定义在 |
|---|---|---|
| checkEtag() | Check if the etag supplied by the client matches our generated one | CHttpCacheFilter |
| checkLastModified() | Checks if the last modified date supplied by the client is still up to date | CHttpCacheFilter |
| generateEtag() | Generates a quoted string out of the seed | CHttpCacheFilter |
| getEtagValue() | Gets the ETag out of either etagSeedExpression or etagSeed | CHttpCacheFilter |
| getLastModifiedValue() | Gets the last modified value from either lastModifiedExpression or lastModified | CHttpCacheFilter |
| postFilter() | Performs the post-action filtering. | CFilter |
| send304Header() | Sends the 304 HTTP status code to the client | CHttpCacheFilter |
| sendCacheControlHeader() | Sends the cache control header to the client | CHttpCacheFilter |
属性详情
cacheControl
属性
public string $cacheControl;
Http cache control headers. Set this to an empty string in order to keep this header from being sent entirely.
etagSeed
属性
public mixed $etagSeed;
Seed for the ETag. Can be anything that passes through serialize().
etagSeedExpression
属性
public string|callback $etagSeedExpression;
Expression for the ETag seed.
If set, this takes precedence over etagSeed.
The PHP expression will be evaluated using evaluateExpression.
A PHP expression can be any PHP code that has a value. To learn more about what an expression is,
please refer to the php manual.
etagValue
属性
只读
protected string|boolean getEtagValue()
Gets the ETag out of either etagSeedExpression or etagSeed
lastModified
属性
public string|integer $lastModified;
Timestamp for the last modification date. Must be either a string parsable by strtotime() or an integer representing a unix timestamp.
lastModifiedExpression
属性
public string|callback $lastModifiedExpression;
PHP Expression for the last modification date.
If set, this takes precedence over lastModified.
The PHP expression will be evaluated using evaluateExpression.
A PHP expression can be any PHP code that has a value. To learn more about what an expression is,
please refer to the php manual.
lastModifiedValue
属性
只读
protected integer|boolean getLastModifiedValue()
Gets the last modified value from either lastModifiedExpression or lastModified and converts it into a unix timestamp if necessary
方法详情
checkEtag()
方法
|
protected boolean checkEtag(string $etag)
| ||
| $etag | string | the supplied etag |
| {return} | boolean | true if the supplied etag matches $etag |
源码： framework/web/filters/CHttpCacheFilter.php#163 (显示)
protected function checkEtag($etag)
{
return isset($_SERVER['HTTP_IF_NONE_MATCH'])&&$_SERVER['HTTP_IF_NONE_MATCH']==$etag;
}
Check if the etag supplied by the client matches our generated one
checkLastModified()
方法
|
protected boolean checkLastModified(integer $lastModified)
| ||
| $lastModified | integer | the last modified date |
| {return} | boolean | true if the last modified date sent by the client is newer or equal to $lastModified |
源码： framework/web/filters/CHttpCacheFilter.php#173 (显示)
protected function checkLastModified($lastModified)
{
return isset($_SERVER['HTTP_IF_MODIFIED_SINCE'])&&@strtotime($_SERVER['HTTP_IF_MODIFIED_SINCE'])>=$lastModified;
}
Checks if the last modified date supplied by the client is still up to date
generateEtag()
方法
|
protected string generateEtag(mixed $seed)
| ||
| $seed | mixed | Seed for the ETag |
| {return} | string | Quoted string serving as ETag |
源码： framework/web/filters/CHttpCacheFilter.php#207 (显示)
protected function generateEtag($seed)
{
return '"'.base64_encode(sha1(serialize($seed),true)).'"';
}
Generates a quoted string out of the seed
getEtagValue()
方法
|
protected string|boolean getEtagValue()
| ||
| {return} | string|boolean | Either a quoted string serving as ETag or false if neither etagSeed nor etagSeedExpression have been set |
源码： framework/web/filters/CHttpCacheFilter.php#149 (显示)
protected function getEtagValue()
{
if($this->etagSeedExpression)
return $this->generateEtag($this->evaluateExpression($this->etagSeedExpression));
elseif($this->etagSeed)
return $this->generateEtag($this->etagSeed);
return false;
}
Gets the ETag out of either etagSeedExpression or etagSeed
getLastModifiedValue()
方法
|
protected integer|boolean getLastModifiedValue()
| ||
| {return} | integer|boolean | A unix timestamp or false if neither lastModified nor lastModifiedExpression have been set |
源码： framework/web/filters/CHttpCacheFilter.php#121 (显示)
protected function getLastModifiedValue()
{
if($this->lastModifiedExpression)
{
$value=$this->evaluateExpression($this->lastModifiedExpression);
if(is_numeric($value)&&$value==(int)$value)
return $value;
elseif(($lastModified=strtotime($value))===false)
throw new CException(Yii::t('yii','Invalid expression for CHttpCacheFilter.lastModifiedExpression: The evaluation result "{value}" could not be understood by strtotime()',
array('{value}'=>$value)));
return $lastModified;
}
if($this->lastModified)
{
if(is_numeric($this->lastModified)&&$this->lastModified==(int)$this->lastModified)
return $this->lastModified;
elseif(($lastModified=strtotime($this->lastModified))===false)
throw new CException(Yii::t('yii','CHttpCacheFilter.lastModified contained a value that could not be understood by strtotime()'));
return $lastModified;
}
return false;
}
Gets the last modified value from either lastModifiedExpression or lastModified and converts it into a unix timestamp if necessary
preFilter()
方法
|
public boolean preFilter(CFilterChain $filterChain)
| ||
| $filterChain | CFilterChain | the filter chain that the filter is on. |
| {return} | boolean | whether the filtering process should continue and the action should be executed. |
源码： framework/web/filters/CHttpCacheFilter.php#63 (显示)
public function preFilter($filterChain)
{
// Only cache GET and HEAD requests
if(!in_array(Yii::app()->getRequest()->getRequestType(), array('GET', 'HEAD')))
return true;
$lastModified=$this->getLastModifiedValue();
$etag=$this->getEtagValue();
if($etag===false&&$lastModified===false)
return true;
if($etag)
header('ETag: '.$etag);
if(isset($_SERVER['HTTP_IF_MODIFIED_SINCE'])&&isset($_SERVER['HTTP_IF_NONE_MATCH']))
{
if($this->checkLastModified($lastModified)&&$this->checkEtag($etag))
{
$this->send304Header();
$this->sendCacheControlHeader();
return false;
}
}
elseif(isset($_SERVER['HTTP_IF_MODIFIED_SINCE']))
{
if($this->checkLastModified($lastModified))
{
$this->send304Header();
$this->sendCacheControlHeader();
return false;
}
}
elseif(isset($_SERVER['HTTP_IF_NONE_MATCH']))
{
if($this->checkEtag($etag))
{
$this->send304Header();
$this->sendCacheControlHeader();
return false;
}
}
if($lastModified)
header('Last-Modified: '.gmdate('D, d M Y H:i:s', $lastModified).' GMT');
$this->sendCacheControlHeader();
return true;
}
Performs the pre-action filtering.
send304Header()
方法
|
protected void send304Header()
|
源码： framework/web/filters/CHttpCacheFilter.php#181 (显示)
protected function send304Header()
{
$httpVersion=Yii::app()->request->getHttpVersion();
header("HTTP/$httpVersion 304 Not Modified");
}
Sends the 304 HTTP status code to the client
sendCacheControlHeader()
方法
（自版本 v1.1.12 可用）
|
protected void sendCacheControlHeader()
|
源码： framework/web/filters/CHttpCacheFilter.php#192 (显示)
protected function sendCacheControlHeader()
{
if(Yii::app()->session->isStarted)
{
Yii::app()->session->setCacheLimiter('public');
header('Pragma:',true);
}
header('Cache-Control: '.$this->cacheControl,true);
}
Sends the cache control header to the client