001    // Copyright 2006, 2007, 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.annotations.Parameter;
018    import org.apache.tapestry5.corelib.base.AbstractConditional;
019    
020    /**
021     * Conditionally renders its body. May render its tag and any informal parameters.
022     * 
023     * @tapestrydoc
024     */
025    public class If extends AbstractConditional
026    {
027        /**
028         * If true, then the body of the If component is rendered. If false, the body is omitted.
029         */
030        @Parameter(required = true)
031        private boolean test;
032    
033        /**
034         * Optional parameter to invert the test. If true, then the body is rendered when the test parameter is false (not
035         * true).
036         * 
037         * @see Unless
038         * @deprecated Since 5.3 as property expressions support the '!' invert operator
039         */
040        @Parameter
041        private boolean negate;
042    
043        /**
044         * @return test parameter (if negate is false), or test parameter inverted (if negate is true)
045         */
046        protected boolean test()
047        {
048            return test != negate;
049        }
050    
051    }