001    // Copyright 2005 The Apache Software Foundation
002    //
003    // Licensed under the Apache License, Version 2.0 (the "License");
004    // you may not use this file except in compliance with the License.
005    // You may obtain a copy of the License at
006    //
007    //     http://www.apache.org/licenses/LICENSE-2.0
008    //
009    // Unless required by applicable law or agreed to in writing, software
010    // distributed under the License is distributed on an "AS IS" BASIS,
011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012    // See the License for the specific language governing permissions and
013    // limitations under the License.
014    
015    package org.apache.tapestry.annotations;
016    
017    import java.lang.annotation.Documented;
018    import java.lang.annotation.ElementType;
019    import java.lang.annotation.Retention;
020    import java.lang.annotation.RetentionPolicy;
021    import java.lang.annotation.Target;
022    
023    /**
024     * Annotation used to <em>define</em> new managed beans, including limited/lightweight
025     * initialization. For complex initialiation, the XML specification is necessary.
026     * <p>
027     * One of the advantages is that, on the XML side, it is always necessary to provide complete class
028     * names; here on the Java/annotation side, we can leverage imports.
029     * <p>
030     * The managed bean will have a name that matches the property name; this allows such a bean to be
031     * referenced via the "bean:" binding prefix, or via
032     * {@link org.apache.tapestry.IComponent#getBeans()}.
033     * <p>
034     * This annotation adds a new {@link org.apache.tapestry.spec.IBeanSpecification} to the
035     * {@link org.apache.tapestry.spec.IComponentSpecification}.
036     * 
037     * @author Howard M. Lewis Ship
038     * @since 4.0
039     */
040    
041    @Target(
042    { ElementType.METHOD })
043    @Retention(RetentionPolicy.RUNTIME)
044    @Documented
045    public @interface Bean {
046        /**
047         * The Java class to instantiate. The default is Object.class; if a non-default value is
048         * specified, that will be the class to instantiate; otherwise, the bean class will be
049         * determined from the property type. Generally, this annotation is only used when the property
050         * type is an interface (or abstract base class).
051         */
052    
053        Class value() default Object.class;
054    
055        /**
056         * Optional initializer string for the bean, as <em>lightweight initialization</em> (a list of
057         * properties and values).
058         */
059    
060        String initializer() default "";
061    
062        /**
063         * The lifecycle of the bean, defaults to Lifecycle.REQUEST.
064         * 
065         * @see BeanLifecycle
066         */
067    
068        Lifecycle lifecycle() default Lifecycle.REQUEST;
069    }