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    
015    package org.apache.tapestry.engine;
016    
017    import org.apache.hivemind.Location;
018    import org.apache.tapestry.IComponent;
019    import org.apache.tapestry.IEngine;
020    import org.apache.tapestry.INamespace;
021    import org.apache.tapestry.IPage;
022    import org.apache.tapestry.IRequestCycle;
023    import org.apache.tapestry.ITemplateComponent;
024    import org.apache.tapestry.spec.IComponentSpecification;
025    
026    /**
027     * Interface exposed to components as they are loaded by the page loader.
028     * 
029     * @see IComponent#finishLoad(IRequestCycle, IPageLoader,
030     *      org.apache.tapestry.spec.IComponentSpecification)
031     * @author Howard Lewis Ship
032     */
033    
034    public interface IPageLoader
035    {
036    
037        /**
038         * Invoked to create an implicit component (one which is defined in the
039         * containing component's template, rather that in the containing
040         * component's specification).
041         * 
042         * @see org.apache.tapestry.services.impl.ComponentTemplateLoaderImpl
043         * @since 3.0
044         */
045    
046        IComponent createImplicitComponent(IRequestCycle cycle,
047                IComponent container, String componentId, String componentType,
048                Location location);
049    
050        /**
051         * Invoked by the {@link IPageSource}to load a specific page. This method
052         * is not reentrant. The page is immediately attached to the
053         * {@link IEngine engine}.
054         * 
055         * @param name
056         *            the simple (unqualified) name of the page to load
057         * @param namespace
058         *            from which the page is to be loaded (used when resolving
059         *            components embedded by the page)
060         * @param cycle
061         *            the request cycle the page is initially loaded for (this is
062         *            used to define the locale of the new page, and provide access
063         *            to the corect specification source, etc.).
064         * @param specification
065         *            the specification for the page
066         */
067    
068        IPage loadPage(String name, INamespace namespace,
069                IRequestCycle cycle, IComponentSpecification specification);
070    
071        /**
072         * Invoked by a component (from within its
073         * {@link IComponent#finishLoad(IRequestCycle, IPageLoader, IComponentSpecification)}method)
074         * to load the template for the component. This will result in new
075         * components being created, and the "outers" of the component being
076         * updated.
077         * 
078         * @see ITemplateComponent
079         * @since 4.0
080         */
081        void loadTemplateForComponent(IRequestCycle cycle,
082                ITemplateComponent component);
083    }