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    import org.apache.tapestry.spec.BeanLifecycle;
024    
025    /**
026     * Annotation used to <em>define</em> new managed beans, including limited/lightweight
027     * initialization. For complex initialiation, the XML specification is necessary.
028     * <p>
029     * One of the advantages is that, on the XML side, it is always necessary to provide complete class
030     * names; here on the Java/annotation side, we can leverage imports.
031     * <p>
032     * The managed bean will have a name that matches the property name; this allows such a bean to be
033     * referenced via the "bean:" binding prefix, or via
034     * {@link org.apache.tapestry.IComponent#getBeans()}.
035     * <p>
036     * This annotation adds a new {@link org.apache.tapestry.spec.IBeanSpecification} to the
037     * {@link org.apache.tapestry.spec.IComponentSpecification}.
038     * 
039     * @author Howard M. Lewis Ship
040     * @since 4.0
041     */
042    
043    @Target(
044    { ElementType.METHOD })
045    @Retention(RetentionPolicy.RUNTIME)
046    @Documented
047    public @interface Bean {
048        /**
049         * The Java class to instantiate. The default is Object.class; if a non-default value is
050         * specified, that will be the class to instantiate; otherwise, the bean class will be
051         * determined from the property type. Generally, this annotation is only used when the property
052         * type is an interface (or abstract base class).
053         */
054    
055        Class value() default Object.class;
056    
057        /**
058         * Optional initializer string for the bean, as <em>lightweight initialization</em> (a list of
059         * properties and values).
060         */
061    
062        String initializer() default "";
063    
064        /**
065         * The lifecycle of the bean, defaults to Lifecycle.REQUEST.
066         * 
067         * @see BeanLifecycle
068         */
069    
070        Lifecycle lifecycle() default Lifecycle.REQUEST;
071    }