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.engine;
016
017import org.apache.hivemind.Location;
018import org.apache.tapestry.IComponent;
019import org.apache.tapestry.INamespace;
020import org.apache.tapestry.IPage;
021import org.apache.tapestry.IRequestCycle;
022import org.apache.tapestry.ITemplateComponent;
023import org.apache.tapestry.spec.IComponentSpecification;
024
025/**
026 * Interface exposed to components as they are loaded by the page loader.
027 * 
028 * @see IComponent#finishLoad(IRequestCycle, IPageLoader,
029 *      org.apache.tapestry.spec.IComponentSpecification)
030 * @author Howard Lewis Ship
031 */
032
033public interface IPageLoader
034{
035    /**
036     * Invoked to create an implicit component (one which is defined in the containing component's
037     * template, rather that in the containing component's specification).
038     * 
039     * @see org.apache.tapestry.services.impl.ComponentTemplateLoaderImpl
040     * @since 3.0
041     */
042
043    public IComponent createImplicitComponent(IRequestCycle cycle, IComponent container, String componentId,
044            String componentType, Location location);
045
046    /**
047     * Invoked by the {@link IPageSource}to load a specific page. This method is not reentrant. The
048     * page is immediately attached to the {@link IEngine engine}.
049     * 
050     * @param name
051     *            the simple (unqualified) name of the page to load
052     * @param namespace
053     *            from which the page is to be loaded (used when resolving components embedded by
054     *            the page)
055     * @param cycle
056     *            the request cycle the page is initially loaded for (this is used to define the
057     *            locale of the new page, and provide access to the corect specification source,
058     *            etc.).
059     * @param specification
060     *            the specification for the page
061     */
062
063    public IPage loadPage(String name, INamespace namespace, IRequestCycle cycle, IComponentSpecification specification);
064
065    /**
066     * Invoked by a component (from within its
067     * {@link IComponent#finishLoad(IRequestCycle, IPageLoader, IComponentSpecification)}method) to
068     * load the template for the component. This will result in new components being created, and
069     * the "outers" of the component being updated.
070     * 
071     * @see ITemplateComponent
072     * @since 4.0
073     */
074    public void loadTemplateForComponent(IRequestCycle cycle, ITemplateComponent component);
075}