PageScoped.java

/**
 * Copyright 2010 Marko Lavikainen
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package net.contextfw.web.application.lifecycle;

import static java.lang.annotation.ElementType.TYPE;
import static java.lang.annotation.RetentionPolicy.RUNTIME;

import java.lang.annotation.Retention;
import java.lang.annotation.Target;

import com.google.inject.ScopeAnnotation;

/**
 * Denotes that there must exist only on instance of this class in one page
 * 
 * <p>
 *  To make this annotation usable, the class must be injected by Guice.
 *  By making page components or other helper classes page scoped they
 *  are easily accessible from different classes and still be 
 *  certain that the instance is always the same. 
 * </p>
 */
@Target( { TYPE })
@Retention(RUNTIME)
@ScopeAnnotation
public @interface PageScoped {
}