org.broadleafcommerce.common.extension
Class ExtensionManager<T extends ExtensionHandler>

java.lang.Object
  org.broadleafcommerce.common.extension.ExtensionManager<T>

Type Parameters:

T -

All Implemented Interfaces:

InvocationHandler

public abstract class ExtensionManager<T extends ExtensionHandler>
extends Object
implements InvocationHandler

The ExtensionManager pattern is intended for out of box components to be extended by Broadleaf modules. Each component that needs an extension should define an interface which is a descendant of ExtensionHandler. The concrete ExtensionManager class will utilize that interface as a parameter (e.g. T below). The default extension manager pattern loops through all handlers and examines their ExtensionResultStatusType to determine whether or not to continue with other handlers.

Author:

bpolster

Field Summary

protected T	extensionHandler
protected List<T>	handlers
protected boolean	handlersSorted
protected static String	LOCK_OBJECT

Constructor Summary

ExtensionManager(Class<T> _clazz)
Should take in a className that matches the ExtensionHandler interface being managed.

Method Summary

boolean	continueOnHandled() Returns whether or not this extension manager continues on ExtensionResultStatusType.HANDLED.
List<T>	getHandlers() If you are attempting to register a handler with this manager and are invoking this outside of an ExtensionManager subclass, consider using registerHandler(ExtensionHandler) instead.
int	getPriority() ExtensionManagers don't really need a priority but they pick up this property due to the fact that we want them to implement the same interface as the handlers they are managing.
T	getProxy()
Object	invoke(Object proxy, Method method, Object[] args)
boolean	registerHandler(T handler) Intended to be invoked from the extension handlers themselves.
void	setHandlers(List<T> handlers)
boolean	shouldContinue(ExtensionResultStatusType result, ExtensionHandler handler, Method method, Object[] args) Utility method that is useful for determining whether or not an ExtensionManager implementation should continue after processing a ExtensionHandler call.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

handlersSorted

protected boolean handlersSorted

LOCK_OBJECT

protected static String LOCK_OBJECT

extensionHandler

protected T extends ExtensionHandler extensionHandler

handlers

protected List<T extends ExtensionHandler> handlers

Constructor Detail

ExtensionManager

public ExtensionManager(Class<T> _clazz)

Should take in a className that matches the ExtensionHandler interface being managed.

Parameters:

className -

Method Detail

getProxy

public T getProxy()

getHandlers

public List<T> getHandlers()

If you are attempting to register a handler with this manager and are invoking this outside of an ExtensionManager subclass, consider using registerHandler(ExtensionHandler) instead. While the sorting of the handlers prior to their return is thread safe, adding directly to this list is not.

Returns:

a list of handlers sorted by their priority

See Also:

#registerHandler(ExtensionHandler)}

registerHandler

public boolean registerHandler(T handler)

Intended to be invoked from the extension handlers themselves. This will add the given handler to this manager's list of handlers. This also checks to ensure that the handler has not been already registered with this ExtensionManager by checking the class names of the already-added handlers. This method is thread safe.

Parameters:

handler - the handler to register with this extension manager

Returns:

true if the handler was successfully registered, false if this handler was already contained in the list of handlers for this manager

setHandlers

public void setHandlers(List<T> handlers)

shouldContinue

public boolean shouldContinue(ExtensionResultStatusType result,
                              ExtensionHandler handler,
                              Method method,
                              Object[] args)

Utility method that is useful for determining whether or not an ExtensionManager implementation should continue after processing a ExtensionHandler call. By default, returns true for CONTINUE

Returns:

continueOnHandled

public boolean continueOnHandled()

Returns whether or not this extension manager continues on ExtensionResultStatusType.HANDLED.

Returns:

getPriority

public int getPriority()

ExtensionManagers don't really need a priority but they pick up this property due to the fact that we want them to implement the same interface as the handlers they are managing.

Returns:

invoke

public Object invoke(Object proxy,
                     Method method,
                     Object[] args)
              throws Throwable

Specified by:

invoke in interface InvocationHandler

Throws:

Throwable