001// Copyright 2004, 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
015package org.apache.tapestry.resolver;
016
017import org.apache.tapestry.INamespace;
018import org.apache.tapestry.IRequestCycle;
019import org.apache.tapestry.spec.IComponentSpecification;
020
021/**
022 * Delegate interface used when a page or component specification can not be found by the normal
023 * means. This allows hooks to support specifications from unusual locations, or generated on the
024 * fly.
025 * <p>
026 * The delegate must be coded in a threadsafe manner.
027 * 
028 * @author Howard Lewis Ship
029 * @since 3.0
030 */
031
032public interface ISpecificationResolverDelegate
033{
034    /**
035     * Invoked by {@link PageSpecificationResolver} to find the indicated page specification.
036     * Returns the specification, or null. The specification, if returned, <em>will be cached</em>
037     * (this represents a change from release 3.0 to release 4.0).
038     * 
039     * @param cycle
040     *            used to gain access to framework and Servlet API objects
041     * @param namespace
042     *            the namespace containing the page
043     * @param simplePageName
044     *            the name of the page (without any namespace prefix)
045     */
046
047    public IComponentSpecification findPageSpecification(IRequestCycle cycle, INamespace namespace,
048            String simplePageName);
049
050    /**
051     * Invoked by {@link PageSpecificationResolver} to find the indicated component specification.
052     * Returns the specification, or null. The specification <em>will be cached</em> (this
053     * represents a change from release 3.0 to release 4.0).
054     * 
055     * @param cycle
056     *            used to gain access to framework and Servlet API objects
057     * @param namespace
058     *            the namespace containing the component
059     * @param type
060     *            the component type (without any namespace prefix)
061     */
062
063    public IComponentSpecification findComponentSpecification(IRequestCycle cycle,
064            INamespace namespace, String type);
065}