SessionThreadSafeSimpleLoadableDetachableModel.java

package fr.openwide.core.wicket.more.model.threadsafe;

import org.apache.wicket.Session;
import org.apache.wicket.model.IModel;
import org.apache.wicket.model.LoadableDetachableModel;

import fr.openwide.core.wicket.more.model.threadsafe.impl.AbstractThreadSafeLoadableDetachableModel;
import fr.openwide.core.wicket.more.model.threadsafe.impl.LoadableDetachableModelThreadContext;

/**
 * An implementation of {@link LoadableDetachableModel} that is thread-safe, and may thus be used in multiple request cycles at the same time.
 * <p>When in doubt, use this class as a basis for your thread-safe loadable/detachable model.
 * <p>This class should be used when :
 * <ul>
 * 	<li>the model is stored in a global object, such as the {@link Session wicket session}
 * 	<li>the serializable state of this loadable/detachable model is empty (no non-transient member) or not directly related to the model object (for instance, it is contained in a member whose type is {@link IModel}).
 * </ul>
 *
 * @param <T> The type of the model object.
 */
public abstract class SessionThreadSafeSimpleLoadableDetachableModel<T>
		extends AbstractThreadSafeLoadableDetachableModel<T, SessionThreadSafeSimpleLoadableDetachableModel<T>.ThreadContextImpl> {
	
	private static final long serialVersionUID = 6859907414385876596L;

	protected class ThreadContextImpl extends LoadableDetachableModelThreadContext<T> { }
	
	public SessionThreadSafeSimpleLoadableDetachableModel() { }

	public SessionThreadSafeSimpleLoadableDetachableModel(T object) {
		setObject(object);
	}
	
	@Override
	protected final ThreadContextImpl newThreadContext() {
		return new ThreadContextImpl();
	}
	
	@Override
	protected final T load(ThreadContextImpl threadContext) {
		return load();
	}

	/**
	 * Loads the model object value from the implementation-defined data source.
	 */
	protected abstract T load();
	
	@Override
	protected final void onSetObject(ThreadContextImpl threadContext) {
		save(threadContext.getTransientModelObject());
	}
	
	protected void save(T object) {
		// Does nothing by default
	}
	
	@Override
	protected final void onDetach(ThreadContextImpl threadContext) {
		onDetach();
	}

	protected void onDetach() {
		// Does nothing by default
	}
	
	@Override
	protected void onDetachDetached() {
		// Does nothing by default
	}

}