tapestry/tapestry-framework/src/java/org/apache/tapestry/IBeanProvider.java

// Copyright 2004, 2005 The Apache Software Foundation
//
// 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 org.apache.tapestry;

import java.util.Collection;

import org.apache.hivemind.ApplicationRuntimeException;
import org.apache.hivemind.ClassResolver;

/**
 * An object that provides a component with access to helper beans. Helper beans
 * are JavaBeans associated with a page or component that are used to extend the
 * functionality of the component via aggregation.
 * 
 * @author Howard Lewis Ship
 * @since 1.0.4
 */

public interface IBeanProvider
{

    /**
     * Returns the JavaBean with the specified name. The bean is created as
     * needed.
     * 
     * @throws ApplicationRuntimeException
     *             if no such bean is available.
     */

    Object getBean(String name);

    /**
     * Returns the {@link IComponent} (which may be a
     * {@link org.apache.tapestry.IPage}) for which this bean provider is
     * providing beans.
     * 
     * @since 1.0.5
     */

    IComponent getComponent();

    /**
     * Returns a collection of the names of any beans which may be provided.
     * 
     * @since 1.0.6
     * @see org.apache.tapestry.spec.IComponentSpecification#getBeanNames()
     */

    Collection getBeanNames();

    /**
     * Returns true if the provider can provide the named bean.
     * 
     * @since 2.2
     */

    boolean canProvideBean(String name);

    /**
     * Returns a resource resolver.
     * 
     * @since 1.0.8
     */

    ClassResolver getClassResolver();

}