    001    // Copyright 2007, 2008, 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.corelib.components;
    016
    017    import org.apache.tapestry5.BindingConstants;
    018    import org.apache.tapestry5.ComponentResources;
    019    import org.apache.tapestry5.Link;
    020    import org.apache.tapestry5.MarkupWriter;
    021    import org.apache.tapestry5.annotations.Parameter;
    022    import org.apache.tapestry5.corelib.base.AbstractLink;
    023    import org.apache.tapestry5.ioc.annotations.Inject;
    024
    025    /**
    026     * Generates a render request link to some other page in the application. If an activation context is supplied (as the
    027     * context parameter), then the context values will be encoded into the URL. If no context is supplied, then the target
    028     * page itself will supply the context via a passivate event.
    029     * <p/>
    030     * Pages are not required to have an activation context. When a page does have an activation context, the value
    031     * typically represents the identity of some object displayed or otherwise manipulated by the page.
    032     *
    033     * @tapestrydoc
    034     */
    035    public class PageLink extends AbstractLink
    036    {
    037        /**
    038         * The logical name of the page to link to.
    039         */
    040        @Parameter(required = true, allowNull = false, defaultPrefix = BindingConstants.LITERAL)
    041        private String page;
    042
    043        @Inject
    044        private ComponentResources resources;
    045
    046        /**
    047         * If provided, this is the activation context for the target page (the information will be encoded into the URL).
    048         * If not provided, then the target page will provide its own activation context.
    049         */
    050        @Parameter
    051        private Object[] context;
    052
    053        void beginRender(MarkupWriter writer)
    054        {
    055            if (isDisabled()) return;
    056
    057            Link link = resources.createPageLink(page, resources.isBound("context"), context);
    058
    059            writeLink(writer, link);
    060        }
    061
    062        void afterRender(MarkupWriter writer)
    063        {
    064            if (isDisabled()) return;
    065
    066            writer.end(); // <a>
    067        }
    068    }