Added TOutputCache.OnCheckDependency event.

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);

+	}

+}

+

 ?>
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