    001    // Copyright 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.annotations.Parameter;
    018    import org.apache.tapestry5.corelib.base.AbstractConditional;
    019
    020    /**
    021     * A close relative of the {@link org.apache.tapestry5.corelib.components.If} component that inverts the meaning of its
    022     * test. This is easier than an {@link org.apache.tapestry5.corelib.components.If} component with the negate parameter set to {@code true}.
    023     *
    024     * @tapestrydoc
    025     */
    026    public class Unless extends AbstractConditional
    027    {
    028        /**
    029         * If true, then the body of the component is omitted. If false, the body is rendered.
    030         */
    031        @Parameter(required = true)
    032        private boolean test;
    033
    034        /**
    035         * @return test parameter inverted
    036         */
    037        protected boolean test()
    038        {
    039            return !test;
    040        }
    041    }