trunk/core/src/main/java/org/apache/struts2/components/Else.java

/*
 * $Id$
 *
 * Copyright 2006 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.struts2.components;

import java.io.Writer;
import java.util.Map;

import com.opensymphony.xwork2.util.OgnlValueStack;

/**
 * <!-- START SNIPPET: javadoc -->
 *
 * <p>Perform basic condition flow. 'If' tag could be used by itself or with 'Else If' Tag and/or single/multiple 'Else'
 * Tag.</p>
 *
 * <!-- END SNIPPET: javadoc -->
 *
 * <!-- START SNIPPET: params -->
 *
 * no params
 *
 * <!-- END SNIPPET: params -->
 *
 *
 * <pre>
 * <!-- START SNIPPET: example -->
 *  &lt;s:if test="%{false}"&gt;
 * 	    &lt;div&gt;Will Not Be Executed&lt;/div&gt;
 *  &lt;/s:if&gt;
 * 	&lt;s:elseif test="%{true}"&gt;
 * 	    &lt;div&gt;Will Be Executed&lt;/div&gt;
 *  &lt;/s:elseif&gt;
 *  &lt;s:else&gt;
 * 	    &lt;div&gt;Will Not Be Executed&lt;/div&gt;
 *  &lt;/s:else&gt;
 * <!-- END SNIPPET: example -->
 * </pre>
 *
 * @s.tag name="else" bodycontent="JSP" description="Else tag"  tld-tag-class="org.apache.struts2.views.jsp.ElseTag"
 */
public class Else extends Component {
    public Else(OgnlValueStack stack) {
        super(stack);
    }

    public boolean start(Writer writer) {
        Map context = stack.getContext();
        Boolean ifResult = (Boolean) context.get(If.ANSWER);

        context.remove(If.ANSWER);

        return !((ifResult == null) || (ifResult.booleanValue()));
    }
}