    001    // Copyright 2006, 2008, 2009, 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.ioc;
    016
    017    /**
    018     * Object passed into a service contributor method that allows the method provide contributed values to the service's
    019     * configuration.
    020     * <p/>
    021     * A service can <em>collect</em> contributions in three different ways:
    022     * <ul>
    023     * <li>As an un-ordered collection of values</li>
    024     * <li>As an ordered list of values (where each value has a unique id, pre-requisites and post-requisites)</li>
    025     * <li>As a map of keys and values
    026     * </ul>
    027     * <p/>
    028     * The service defines the <em>type</em> of contribution, in terms of a base class or service interface. Contributions
    029     * must be compatible with the type, or be {@linkplain org.apache.tapestry5.ioc.services.TypeCoercer coercable} to the type.
    030     *
    031     * @see org.apache.tapestry5.ioc.annotations.Contribute
    032     * @see org.apache.tapestry5.ioc.annotations.UsesConfiguration
    033     */
    034    public interface OrderedConfiguration<T>
    035    {
    036        /**
    037         * Adds an ordered object to a service's contribution. Each object has an id (which must be unique). Optionally,
    038         * pre-requisites (a list of ids that must precede this object) and post-requisites (ids that must follow) can be
    039         * provided.
    040         * <p/>
    041         * <p>If no constraints are supplied, then an implicit constraint is supplied: after the previously
    042         * contributed id <em>within the same contribution method</em>.
    043         *
    044         * @param id          a unique id for the object; the id will be fully qualified with the contributing module's id
    045         * @param constraints used to order the object relative to other contributed objects
    046         * @param object      to add to the service's configuration
    047         */
    048        void add(String id, T object, String... constraints);
    049
    050        /**
    051         * Overrides a normally contributed object. Each override must match a single normally contributed object.
    052         *
    053         * @param id          identifies object to override
    054         * @param object      overriding object (may be null)
    055         * @param constraints constraints for the overridden object, replacing constraints for the original object (even if
    056         *                    omitted, in which case the override object will have no ordering constraints)
    057         * @since 5.1.0.0
    058         */
    059        void override(String id, T object, String... constraints);
    060
    061        /**
    062         * Adds an ordered object by instantiating (with dependencies) the indicated class. When the configuration type is
    063         * an interface and the class to be contributed is a local file,
    064         * then a reloadable proxy for the class will be created and contributed.
    065         *
    066         * @param id          of contribution (used for ordering)
    067         * @param clazz       class to instantiate
    068         * @param constraints used to order the object relative to other contributed objects
    069         * @since 5.1.0.0
    070         */
    071        void addInstance(String id, Class<? extends T> clazz, String... constraints);
    072
    073        /**
    074         * Instantiates an object and adds it as an override. When the configuration type is an interface and the class to
    075         * be contributed is a local file, then a reloadable proxy for the class will be created and contributed.
    076         *
    077         * @param id          of object to override
    078         * @param clazz       to instantiate
    079         * @param constraints constraints for the overridden object, replacing constraints for the original object (even if
    080         *                    omitted, in which case the override object will have no ordering constraints)
    081         * @since 5.1.0.0
    082         */
    083        void overrideInstance(String id, Class<? extends T> clazz, String... constraints);
    084    }