001    /*
002     * Copyright 2007 Robin Helgelin
003     *
004     * Licensed under the Apache License, Version 2.0 (the "License");
005     * you may not use this file except in compliance with the License.
006     * You may obtain a copy of the License at
007     *
008     *     http://www.apache.org/licenses/LICENSE-2.0
009     *
010     * Unless required by applicable law or agreed to in writing, software
011     * distributed under the License is distributed on an "AS IS" BASIS,
012     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013     * See the License for the specific language governing permissions and
014     * limitations under the License.
015     */
016    
017    package nu.localhost.tapestry.acegi.components;
018    
019    import java.security.Principal;
020    
021    import org.apache.tapestry.Block;
022    import org.apache.tapestry.annotations.Parameter;
023    import org.apache.tapestry.ioc.annotations.Inject;
024    import org.apache.tapestry.services.RequestGlobals;
025    
026    /**
027     * Render it's body depending whether the user is logged in or not.
028     * 
029     * @author Robin Helgelin
030     * @author Tapestry Project (doc comments)
031     */
032    public class IfLoggedIn {
033        /**
034         * Optional parameter to invert the test. If true, then the body is rendered when the test
035         * parameter is false (not true).
036         */
037        @Parameter
038        private boolean negate;
039    
040        /**
041         * An alternate {@link Block} to render if the test parameter is false. The default, null, means
042         * render nothing in that situation.
043         */
044        @Parameter(name = "else")
045        private Block elseBlock;
046    
047        @Inject
048        private RequestGlobals requestGlobals;
049        
050        private boolean test() {
051            Principal principal = requestGlobals.getHTTPServletRequest().getUserPrincipal();
052            return principal != null && principal.getName() != "";
053        }
054    
055        /**
056         * Returns null if the test method returns true, which allows normal rendering (of the body). If
057         * the test parameter is false, returns the else parameter (this may also be null).
058         */
059        Object beginRender() {
060            if (test() != negate) {
061                return null;
062            } else {
063                return elseBlock;
064            }
065        }
066    
067        /**
068         * If the test method returns true, then the body is rendered, otherwise not. The component does
069         * not have a template or do any other rendering besides its body.
070         */
071        boolean beforeRenderBody() {
072            return test() != negate;
073        }
074    
075        void setup(String role, boolean negate, Block elseBlock) {
076            this.negate = negate;
077            this.elseBlock = elseBlock;
078        }
079    }