| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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 org.apache.struts2.views.annotations.StrutsTag; |
| import org.apache.struts2.views.annotations.StrutsTagAttribute; |
| |
| import com.opensymphony.xwork2.util.ValueStack; |
| |
| /** |
| * <!-- START SNIPPET: javadoc --> |
| * <p>Push value on stack for simplified usage.</p> |
| * <!-- END SNIPPET: javadoc --> |
| * |
| * <!-- START SNIPPET: params --> |
| * <ul> |
| * <li>value* (Object) - value to be pushed into the top of the stack</li> |
| * </ul> |
| * <!-- END SNIPPET: params --> |
| * |
| * |
| * <p><b>Examples</b></p> |
| * <pre> |
| * <!-- START SNIPPET: example1 --> |
| * <s:push value="user"> |
| * <s:propery value="firstName" /> |
| * <s:propery value="lastName" /> |
| * </s:push> |
| * <!-- END SNIPPET: example1 --> |
| * </pre> |
| * |
| * <!-- START SNIPPET: example1description --> |
| * Pushed user into the stack, and hence property tag could access user's properties |
| * (firstName, lastName etc) since user is now at the top of the stack |
| * <!-- END SNIPPET: example1description --> |
| * |
| * <pre> |
| * <!-- START SNIPPET: example2 --> |
| * <s:push value="myObject"> ----- (1) |
| * <s:bean name="jp.SomeBean" var="myBean"/> ----- (2) |
| * <s:param name="myParam" value="top"/> ----- (3) |
| * </s:bean> |
| * </s:push> |
| * <!-- END SNIPPET: example2 --> |
| * </pre> |
| * |
| * <pre> |
| * <!-- START SNIPPET: example2description --> |
| * when in (1), myObject is at the top of the stack |
| * when in (2), jp.SomeBean is in the top of stack, also in stack's context with key myBean |
| * when in (3), top will get the jp.SomeBean instance |
| * <!-- END SNIPPET: example2description --> |
| * </pre> |
| * |
| * <pre> |
| * <!-- START SNIPPET: example3 --> |
| * <s:push value="myObject"> ---(A) |
| * <s:bean name="jp.SomeBean" var="myBean"/> ---(B) |
| * <s:param name="myParam" value="top.mySomeOtherValue"/> ---(C) |
| * </s:bean> |
| * </s:push> |
| * <!-- END SNIPPET: example3 --> |
| * </pre> |
| * |
| * <pre> |
| * <!-- START SNIPPET: example3description --> |
| * when in (A), myObject is at the top of the stack |
| * when in (B), jp.SomeBean is at the top of the stack, also in context with key myBean |
| * when in (C), top refers to jp.SomeBean instance. so top.mySomeOtherValue would invoke SomeBean's mySomeOtherValue() method |
| * <!-- END SNIPPET: example3description --> |
| * </pre> |
| * |
| * <pre> |
| * <!-- START SNIPPET: example4 --> |
| * <s:push value="myObject"> ---- (i) |
| * <s:bean name="jp.SomeBean" var="myBean"/> ---- (ii) |
| * <s:param name="myParam" value="[1].top"/> -----(iii) |
| * </s:bean> |
| * </s:push> |
| * <!-- END SNIPPET: example4 --> |
| * </pre> |
| * |
| * <pre> |
| * <!-- START SNIPPET: example4description --> |
| * when in (i), myObject is at the top of the stack |
| * when in (ii), jp.SomeBean is at the top of the stack, followed by myObject |
| * when in (iii), [1].top will returned top of the cut of stack starting from myObject, namely myObject itself |
| * <!-- END SNIPPET: example4description --> |
| * </pre> |
| * |
| */ |
| @StrutsTag(name="push", tldTagClass="org.apache.struts2.views.jsp.PushTag", description="Push value on stack for simplified usage.") |
| public class Push extends Component { |
| protected String value; |
| protected boolean pushed; |
| |
| public Push(ValueStack stack) { |
| super(stack); |
| } |
| |
| public boolean start(Writer writer) { |
| boolean result = super.start(writer); |
| |
| ValueStack stack = getStack(); |
| |
| if (stack != null) { |
| stack.push(findValue(value, "value", "You must specify a value to push on the stack. Example: person")); |
| pushed = true; |
| } else { |
| pushed = false; // need to ensure push is assigned, otherwise we may have a leftover value |
| } |
| |
| return result; |
| } |
| |
| public boolean end(Writer writer, String body) { |
| ValueStack stack = getStack(); |
| |
| if (pushed && (stack != null)) { |
| stack.pop(); |
| } |
| |
| return super.end(writer, body); |
| } |
| |
| @StrutsTagAttribute(description="Value to push on stack", required=true) |
| public void setValue(String value) { |
| this.value = value; |
| } |
| |
| } |