    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
    015package org.apache.tapestry5.corelib.components;
    016
    017import org.apache.tapestry5.annotations.Parameter;
    018import 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 */
    025public 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}