[XW-1016] Configuration should distinguish an empty value from a missing value

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.1.2
• Component/s: Configuration
• Assignee: Unassigned
• Reporter: John Patterson
• Created: 23/Apr/05 17:13
• Updated: 18/Jun/12 07:29
• Resolved: 04/Mar/06 14:10

Description

I need to be able to distinguish between a missing parameter and a parameter with an empty value.

When I add a parameter like this

<param name="namespace"></param>

to my xwork.xml I expected that the property 'namespace' would be set to an empty string. In fact the setter is not called at all because empty elements are discarded. Here is a patch to fix this:

Index: XmlHelper.java
===================================================================
RCS file: /cvs/xwork/src/java/com/opensymphony/xwork/config/providers/XmlHelper.java,v
retrieving revision 1.3
diff -u -r1.3 XmlHelper.java
— XmlHelper.java 8 Dec 2004 11:51:24 -0000 1.3
+++ XmlHelper.java 23 Apr 2005 15:06:36 -0000
@@ -1,50 +1,54 @@
-/*

• * Copyright (c) 2002-2003 by OpenSymphony
• * All rights reserved.
• */
  -package com.opensymphony.xwork.config.providers;
  -
  -import org.w3c.dom.Element;
  -import org.w3c.dom.Node;
  -import org.w3c.dom.NodeList;
  -
  -import java.util.HashMap;
  -
  -
  -/**
• * Created by IntelliJ IDEA.
• * User: Mike
• * Date: May 6, 2003
• * Time: 12:12:03 PM
• * To change this template use Options | File Templates.
• */
  -public class XmlHelper {
• //~ Methods ////////////////////////////////////////////////////////////////
  -
• public static HashMap getParams(Element paramsElement) {
• HashMap params = new HashMap();
  -
• if (paramsElement == null) { - return params; - }

  -

• NodeList childNodes = paramsElement.getChildNodes();
  -
• for (int i = 0; i < childNodes.getLength(); i++) {
• Node childNode = childNodes.item;
  -
• if ((childNode.getNodeType() == Node.ELEMENT_NODE) && "param".equals(childNode.getNodeName())) {
• Element paramElement = (Element) childNode;
• String paramName = paramElement.getAttribute("name");
  -
• if (paramElement.getChildNodes().item(0) != null) { - String paramValue = paramElement.getChildNodes().item(0).getNodeValue(); - if (paramValue != null) paramValue = paramValue.trim(); - params.put(paramName, paramValue); - }
• }
• }
  -
• return params;
• }
  -}
  +/*
  + * Copyright (c) 2002-2003 by OpenSymphony
  + * All rights reserved.
  + */
  +package com.opensymphony.xwork.config.providers;
  +
  +import org.w3c.dom.Element;
  +import org.w3c.dom.Node;
  +import org.w3c.dom.NodeList;
  +
  +import java.util.HashMap;
  +
  +
  +/**
  + * Created by IntelliJ IDEA.
  + * User: Mike
  + * Date: May 6, 2003
  + * Time: 12:12:03 PM
  + * To change this template use Options | File Templates.
  + */
  +public class XmlHelper {
  + //~ Methods ////////////////////////////////////////////////////////////////
  +
  + public static HashMap getParams(Element paramsElement) {
  + HashMap params = new HashMap();
  +
  + if (paramsElement == null) { + return params; + }

  +
  + NodeList childNodes = paramsElement.getChildNodes();
  +
  + for (int i = 0; i < childNodes.getLength(); i++) {
  + Node childNode = childNodes.item;
  +
  + if ((childNode.getNodeType() == Node.ELEMENT_NODE) && "param".equals(childNode.getNodeName()))

  Unknown macro: {+ Element paramElement = (Element) childNode;+ String paramName = paramElement.getAttribute("name");+ String paramValue;+ if (paramElement.getChildNodes().item(0) != null) { + paramValue = paramElement.getChildNodes().item(0).getNodeValue(); + if (paramValue != null) paramValue = paramValue.trim(); + + }+ else { + paramValue = ""; + }+ params.put(paramName, paramValue);+ }

  + }
  +
  + return params;
  + }
  +}