diff options
| -rw-r--r-- | framework/Web/UI/WebControls/TOutputCache.php | 71 |
1 files changed, 63 insertions, 8 deletions
diff --git a/framework/Web/UI/WebControls/TOutputCache.php b/framework/Web/UI/WebControls/TOutputCache.php index b1a7fa93..a63b45ec 100644 --- a/framework/Web/UI/WebControls/TOutputCache.php +++ b/framework/Web/UI/WebControls/TOutputCache.php @@ -27,13 +27,18 @@ * where content to be cached can be static text and/or component tags.
*
* The validity of the cached content is determined based on two factors:
- * the {@link setDuration Duration} and the {@link getCacheDependency CacheDependency}.
+ * the {@link setDuration Duration} and the cache dependency.
* The former specifies the number of seconds that the data can remain
- * valid in cache (defaults to 60s), while the latter specifies a dependency
- * that the data depends on. If the dependency changes, the cached content
- * is invalidated. By default, TOutputCache doesn't specify a dependency.
- * Derived classes may override {@link getCacheDependency()} method to
- * enforce a dependency (such as system state change, etc.)
+ * valid in cache (defaults to 60s), while the latter specifies conditions
+ * that the cached data depends on. If a dependency changes,
+ * (e.g. relevant data in DB are updated), the cached data will be invalidated.
+ *
+ * There are two ways to specify cache dependency. One may write event handlers
+ * to respond to the {@link onCheckDependency OnCheckDependency} event and set
+ * the event parameter's {@link TOutputCacheEventParameter::getIsValid IsValid}
+ * property to indicate whether the cached data remains valid or not.
+ * One can also extend TOutputCache and override its {@link getCacheDependency CacheDependency}
+ * function. While the former is easier to use, the latter offers more extensibility.
*
* The content fetched from cache may be variated with respect to
* some parameters. It supports variation with respect to request parameters,
@@ -107,13 +112,16 @@ class TOutputCache extends TControl implements INamingContainer {
$this->_cacheAvailable=true;
$data=$this->_cache->get($this->getCacheKey());
- if(($this->_dataCached=($data!==false)))
+ $param=new TOutputCacheEventParameter;
+ $this->onCheckDependency($param);
+ $this->_dataCached=($data!==false && $param->getIsValid());
+ if($this->_dataCached)
list($this->_contents,$this->_state,$this->_actions)=$data;
}
}
}
}
-
+
/**
* Performs the Init step for the control and all its child controls.
* This method overrides the parent implementation by setting up
@@ -371,6 +379,18 @@ class TOutputCache extends TControl implements INamingContainer }
/**
+ * This event is raised when the output cache is checking cache dependency.
+ * An event handler may be written to check customized dependency conditions.
+ * The checking result should be saved by setting {@link TOutputCacheEventParameter::setIsValid IsValid}
+ * property of the event parameter (which defaults to true).
+ * @param TOutputCacheEventParameter event parameter
+ */
+ public function onCheckDependency($param)
+ {
+ $this->raiseEvent('OnCheckDependency',$this,$param);
+ }
+
+ /**
* Renders the output cache control.
* This method overrides the parent implementation by capturing the output
* from its child controls and saving it into cache, if output cache is needed.
@@ -399,4 +419,39 @@ class TOutputCache extends TControl implements INamingContainer }
}
+/**
+ * TOutputCacheEventParameter class
+ *
+ * TOutputCacheEventParameter encapsulates the parameter data for
+ * <b>OnCheckDependency</b> event of {@link TOutputCache} control.
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @version $Revision: $ $Date: $
+ * @package System.Web.UI.WebControls
+ * @since 3.0
+ */
+class TOutputCacheEventParameter extends TEventParameter
+{
+ /**
+ * @var boolean whether the dependency remains valid
+ */
+ private $_isValid=true;
+
+ /**
+ * @return boolean whether the dependency remains valid. Defaults to true.
+ */
+ public function getIsValid()
+ {
+ return $this->_isValid;
+ }
+
+ /**
+ * @param boolean whether the dependency remains valid
+ */
+ public function setIsValid($value)
+ {
+ $this->_isValid=TPropertyValue::ensureBoolean($value);
+ }
+}
+
?>
\ No newline at end of file |