    001    // Copyright 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.services.pageload;
    016
    017    import java.util.List;
    018
    019    import org.apache.tapestry5.ioc.Resource;
    020    import org.apache.tapestry5.ioc.util.LocalizedNameGenerator;
    021    import org.apache.tapestry5.model.ComponentModel;
    022
    023    /**
    024     * A central service that encapsulates the rules for locating resources for components. The service can be
    025     * overridden, or simply decorated, to implement customized rules for locating templates across
    026     * one or more {@linkplain ComponentResourceSelector#getAxis(Class) axes}; this is the approach used to skin
    027     * Tapestry applications.
    028     *
    029     * @since 5.3
    030     */
    031    public interface ComponentResourceLocator
    032    {
    033        /**
    034         * Locates the template for a component (including pages and base classes). The implementation takes into
    035         * account the locale and other axes specified by the selector. If the method returns null, then the component
    036         * will have no template (which is common for components, but rare for pages).
    037         *
    038         * @param model
    039         *            defines the component, including its {@linkplain ComponentModel#getBaseResource() base resource}.
    040         * @param selector
    041         *            used to identify locale, etc., for the template
    042         * @return Resource for component template, or null if not found
    043         */
    044        Resource locateTemplate(ComponentModel model, ComponentResourceSelector selector);
    045
    046        /**
    047         * Locates the properties files that make up the message catalog for a specific component. The properties
    048         * files are returned in order of specificity: the properties provided by the first resource override
    049         * properties in later resources. Only resources specific to the class associated with the model
    050         * should be concerned (message inheritance from base classes is handled by Tapestry).
    051         *
    052         * @param baseResource
    053         *            the resource for the base component properties file (i.e., with the ".properties" file extension)
    054         * @param selector
    055         *            defined the locale and other axes used to locate individual properties files
    056         * @return list of properties file Resources
    057         * @see LocalizedNameGenerator
    058         */
    059        List<Resource> locateMessageCatalog(Resource baseResource, ComponentResourceSelector selector);
    060    }