    001    // Copyright 2010, 2011 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.tapestry5.internal.services;
    016
    017    import org.apache.tapestry5.internal.structure.Page;
    018    import org.apache.tapestry5.ioc.Resource;
    019    import org.apache.tapestry5.services.dynamic.DynamicTemplate;
    020    import org.apache.tapestry5.services.pageload.ComponentRequestSelectorAnalyzer;
    021    import org.apache.tapestry5.services.pageload.ComponentResourceSelector;
    022
    023    import java.util.Set;
    024
    025    /**
    026     * Access to localized page instances (which are now shared singletons, starting in release 5.2).
    027     * This service is a wrapper around the {@link PageLoader} that caches the loaded pages.
    028     *
    029     * @since 5.2.0
    030     */
    031    public interface PageSource
    032    {
    033        /**
    034         * Clears the source's cache of loaded pages. This occurs when an outside change to the world invalidates
    035         * created page instances. Introduced to handle the case where a page has a {@link DynamicTemplate}, but the
    036         * underlying {@link Resource} is noticed to have changed.
    037         *
    038         * @since 5.3
    039         */
    040        void clearCache();
    041
    042        /**
    043         * Returns a loaded instance of the indicated page, using the Locale and other information
    044         * from the {@link ComponentResourceSelector} obtained from the {@link ComponentRequestSelectorAnalyzer}.
    045         *
    046         * @param canonicalPageName
    047         * @return existing, or newly created, page instance
    048         */
    049        Page getPage(String canonicalPageName);
    050
    051        /**
    052         * Returns all currently loaded pages. This will include any previously loaded pages not yet reclaimed by the
    053         * garbage collector, and may include the same page loaded for different {@link ComponentResourceSelector}s. This is needed
    054         * for reporting purposes only.
    055         *
    056         * @see org.apache.tapestry5.corelib.pages.PageCatalog
    057         * @since 5.3
    058         */
    059        Set<Page> getAllPages();
    060    }