wicket.model
Class LoadableDetachableModel

java.lang.Object
  wicket.model.AbstractModel
      wicket.model.AbstractReadOnlyModel
          wicket.model.LoadableDetachableModel

All Implemented Interfaces:

java.io.Serializable, IDetachable, IModel

public abstract class LoadableDetachableModel
extends AbstractReadOnlyModel

Model that makes working with detachable models a breeze. LoadableDetachableModel holds a temporary, transient model object, that is set when getObject(Component) is called by calling abstract method 'load', and that will be reset/ set to null on detach(). A usage example:

 LoadableDetachableModel venueListModel = new LoadableDetachableModel()
 {
        protected Object load()
        {
                return getVenueDao().findVenues();
        }
 };
 

Though you can override methods onAttach() and onDetach() for additional attach/ detach behavior, the point of this class is to hide as much of the attaching/ detaching as possible. So you should rarely need to override those methods, if ever.

Author:

Eelco Hillenius, Igor Vaynberg

See Also:

Serialized Form

Constructor Summary

LoadableDetachableModel()
Construct.

LoadableDetachableModel(java.lang.Object object)
This constructor is used if you already have the object retrieved and want to wrap it with a detachable model.

Method Summary

void	detach() Detaches model after use.
java.lang.Object	getObject(Component component) Gets the model object.
boolean	isAttached() Gets the attached status of this model instance
protected abstract java.lang.Object	load() Loads and returns the (temporary) model object.
protected void	onAttach() Attaches to the current request.
protected void	onDetach() Detaches from the current request.
java.lang.String	toString()

Methods inherited from class wicket.model.AbstractReadOnlyModel

setObject

Methods inherited from class wicket.model.AbstractModel

getNestedModel

Methods inherited from class java.lang.Object

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

Constructor Detail

LoadableDetachableModel

public LoadableDetachableModel()

Construct.

LoadableDetachableModel

public LoadableDetachableModel(java.lang.Object object)

This constructor is used if you already have the object retrieved and want to wrap it with a detachable model.

Parameters:

object - retrieved instance of the detachable object

Method Detail

detach

public final void detach()

Description copied from interface: IDetachable

Detaches model after use. This is generally used to null out transient references that can be re-attached later.

Specified by:

detach in interface IDetachable

Overrides:

detach in class AbstractModel

See Also:

IDetachable.detach()

getObject

public java.lang.Object getObject(Component component)

Description copied from interface: IModel

Gets the model object.

Specified by:

getObject in interface IModel

Specified by:

getObject in class AbstractReadOnlyModel

Parameters:

component - The component which wants to get a model Object

Returns:

The model object

See Also:

IModel.getObject(wicket.Component)

isAttached

public final boolean isAttached()

Gets the attached status of this model instance

Returns:

true if the model is attached, false otherwise

toString

public java.lang.String toString()

Overrides:

toString in class AbstractReadOnlyModel

See Also:

Object.toString()

load

protected abstract java.lang.Object load()

Loads and returns the (temporary) model object.

Returns:

the (temporary) model object

onAttach

protected void onAttach()

Attaches to the current request. Implement this method with custom behavior, such as loading the model object.

onDetach

protected void onDetach()

Detaches from the current request. Implement this method with custom behavior, such as setting the model object to null.