Hi all,
would someone be able to tell me the correct way to do this, taking
advantage of the nesting?
I expected that after adding errors with the same nested property names as
the nested tags use (eg, "person[0].username"), it might be something like:
<nested:form ...>
...
<nested:nest property="person[0]">
<td>User name:</td>
<td><nested:text property="username" /> <nested:errors
property="username" /></td>
</nested:nest>
...
</nested:form>
and the nested property for the errors tag would use the same "nesting" as
the other nested tags (ie, "person[0]" in this case), but not so, at least
in my version of Struts, circa 1.1.
I have it working like this now, with a few changes to NestedPropertyHelper
(see below), but I can't help thinking I've missed the point.
Thanks in advance,
Maurice
=============
Changes to two methods (complete file below):
public static void setNestedProperties(HttpServletRequest request,
NestedPropertySupport tag) {
boolean adjustProperty = true;
/* if the tag implements NestedNameSupport, set the name for the tag
also */
if (tag instanceof NestedNameSupport) {
NestedNameSupport nameTag = (NestedNameSupport)tag;
if (nameTag.getName() == null
|| Constants.BEAN_KEY.equals(nameTag.getName())
|| Globals.ERROR_KEY.equals(nameTag.getName())) { // ADDED THIS
LINE TO SO THAT THE CURRENT NESTING IS PREPENDED TO THE PROPERTY
nameTag.setName(getCurrentName(request, (NestedNameSupport) tag));
} else {
adjustProperty = false;
}
}
/* get and set the relative property, adjust if required */
String property = tag.getProperty();
if (adjustProperty) {
property = getAdjustedProperty(request, property);
}
tag.setProperty(property);
}
public static final String getCurrentName(HttpServletRequest request,
NestedNameSupport nested) {
// Error Tag?
if (nested instanceof NestedErrorsTag) { // ADDED THESE LINES SO THE
*ERRORS* BEAN IS USED, RATHER THAN THE BEAN USED BY OTHER NESTED TAGS
return Globals.ERROR_KEY;
}
// Rest as before
....
}
=================
Complete file:
/*
* $Header:
/home/cvs/jakarta-struts/src/share/org/apache/struts/taglib/nested/NestedPro
pertyHelper.java,v 1.14 2003/04/22 02:28:52 dgraham Exp $
* $Revision: 1.14 $
* $Date: 2003/04/22 02:28:52 $
* ====================================================================
*
* The Apache Software License, Version 1.1
*
* Copyright (c) 1999-2003 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution, if
* any, must include the following acknowlegement:
* "This product includes software developed by the
* Apache Software Foundation ( http://www.apache.org/
<http://www.apache.org/> )."
* Alternately, this acknowlegement may appear in the software itself,
* if and wherever such third-party acknowlegements normally appear.
*
* 4. The names "The Jakarta Project", "Struts", and "Apache Software
* Foundation" must not be used to endorse or promote products derived
* from this software without prior written permission. For written
* permission, please contact [EMAIL PROTECTED]
<mailto:[EMAIL PROTECTED]> .
*
* 5. Products derived from this software may not be called "Apache"
* nor may "Apache" appear in their names without prior written
* permission of the Apache Group.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* < http://www.apache.org/ <http://www.apache.org/> >.
*
*/
package org.apache.struts.taglib.nested;
import java.util.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.jsp.tagext.Tag;
import org.apache.struts.Globals;
import org.apache.struts.taglib.html.Constants;
import org.apache.struts.taglib.html.FormTag;
import org.apache.struts.taglib.nested.html.NestedErrorsTag;
/**
* <p>A simple helper class that does everything that needs to be done to
get
* the nested tag extension to work. The tags will pass in their relative
* properties and this class will leverage the accessibility of the request
* object to calculate the nested references and manage them from a central
* place.</p>
*
* <p>The helper method [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>
#setNestedProperties} takes
a reference to the
* tag itself so all the simpler tags can have their references managed from
a
* central location. From here, the reference to a provided name is also
* preserved for use.</p>
*
* <p>With all tags keeping track of themselves, we only have to seek to the
* next level, or parent tag, were a tag will append a dot and it's own
* property.</p>
*
* @author Arron Bates
* @since Struts 1.1
* @version $Revision: 1.14 $ $Date: 2003/04/22 02:28:52 $
*/
public class NestedPropertyHelper {
/* key that the tags can rely on to set the details against */
public static final String NESTED_INCLUDES_KEY = "<nested-includes-key/>";
/**
* Returns the current nesting property from the request object.
* @param request object to fetch the property reference from
* @return String of the bean name to nest against
*/
public static final String getCurrentProperty(HttpServletRequest request)
{
// get the old one if any
NestedReference nr = (NestedReference)
request.getAttribute(NESTED_INCLUDES_KEY);
// return null or the property
return (nr == null) ? null : nr.getNestedProperty();
}
/**
* <p>Returns the bean name from the request object that the properties
are
* nesting against.</p>
*
* <p>The requirement of the tag itself could be removed in the future,
but is
* required if support for the <html:form> tag is maintained.</p>
* @param request object to fetch the bean reference from
* @param nested tag from which to start the search from
* @return the string of the bean name to be nesting against
*/
public static final String getCurrentName(HttpServletRequest request,
NestedNameSupport nested) {
// Error Tag?
if (nested instanceof NestedErrorsTag) {
return Globals.ERROR_KEY;
}
// get the old one if any
NestedReference nr = (NestedReference)
request.getAttribute(NESTED_INCLUDES_KEY);
// return null or the property
if (nr != null) {
return nr.getBeanName();
} else {
// need to look for a form tag...
Tag tag = (Tag) nested;
Tag formTag = null;
// loop all parent tags until we get one that can be nested against
do {
tag = tag.getParent();
if (tag != null && tag instanceof FormTag) {
formTag = tag;
}
} while (formTag == null && tag != null);
if (formTag == null) {
return "";
}
// return the form's name
return ((FormTag) formTag).getBeanName();
}
}
/**
* Get the adjusted property.
* Apply the provided property, to the property already stored
* in the request object.
* @param request to pull the reference from
* @param property to retrieve the evaluated nested property with
* @return String of the final nested property reference.
*/
public static final String getAdjustedProperty(HttpServletRequest request,
String property) {
// get the old one if any
String parent = getCurrentProperty(request);
return calculateRelativeProperty(property, parent);
}
/**
* Sets the provided property into the request object for reference by the
* other nested tags.
* @param request object to set the new property into
* @param property String to set the property to
*/
public static final void setProperty(HttpServletRequest request,
String property) {
// get the old one if any
NestedReference nr = referenceInstance(request);
nr.setNestedProperty(property);
}
/**
* Sets the provided name into the request object for reference by the
* other nested tags.
* @param request object to set the new name into
* @param name String to set the name to
*/
public static final void setName(HttpServletRequest request, String name)
{
// get the old one if any
NestedReference nr = referenceInstance(request);
nr.setBeanName(name);
}
/**
* Deletes the nested reference from the request object.
* @param request object to remove the reference from
*/
public static final void deleteReference(HttpServletRequest request) {
// delete the reference
request.removeAttribute(NESTED_INCLUDES_KEY);
}
/**
* Helper method that will set all the relevant nesting properties for the
* provided tag reference depending on the implementation.
* @param request object to pull references from
* @param tag to set the nesting values into
*/
public static void setNestedProperties(HttpServletRequest request,
NestedPropertySupport tag) {
boolean adjustProperty = true;
/* if the tag implements NestedNameSupport, set the name for the tag
also */
if (tag instanceof NestedNameSupport) {
NestedNameSupport nameTag = (NestedNameSupport)tag;
if (nameTag.getName() == null ||
Constants.BEAN_KEY.equals(nameTag.getName()) ||
Globals.ERROR_KEY.equals(nameTag.getName())) {
nameTag.setName(getCurrentName(request, (NestedNameSupport) tag));
} else {
adjustProperty = false;
}
}
/* get and set the relative property, adjust if required */
String property = tag.getProperty();
if (adjustProperty) {
property = getAdjustedProperty(request, property);
}
tag.setProperty(property);
}
/**
* Pulls the current nesting reference from the request object, and if
there
* isn't one there, then it will create one and set it.
* @param request object to manipulate the reference into
* @return current nesting reference as stored in the request object
*/
private static final NestedReference referenceInstance(HttpServletRequest
request) {
/* get the old one if any */
NestedReference nr = (NestedReference)
request.getAttribute(NESTED_INCLUDES_KEY);
// make a new one if required
if (nr == null) {
nr = new NestedReference();
request.setAttribute(NESTED_INCLUDES_KEY, nr);
}
// return the reference
return nr;
}
/* This property, providing the property to be appended, and the parent
tag
* to append the property to, will calculate the stepping of the property
* and return the qualified nested property
*
* @param property the property which is to be appended nesting style
* @param parent the "dot notated" string representing the structure
* @return qualified nested property that the property param is to the
parent
*/
private static String calculateRelativeProperty(String property,
String parent) {
if (parent == null) { parent = ""; }
if (property == null) { property = ""; }
/* Special case... reference my parent's nested property.
Otherwise impossible for things like indexed properties */
if ("./".equals(property) || "this/".equals(property)) {
return parent;
}
/* remove the stepping from the property */
String stepping;
/* isolate a parent reference */
if (property.endsWith("/")) {
stepping = property;
property = "";
} else {
stepping = property.substring(0, property.lastIndexOf('/') + 1);
/* isolate the property */
property = property.substring(property.lastIndexOf('/') + 1,
property.length());
}
if (stepping.startsWith("/")) {
/* return from root */
return property;
} else {
/* tokenize the nested property */
StringTokenizer proT = new StringTokenizer(parent, ".");
int propCount = proT.countTokens();
/* tokenize the stepping */
StringTokenizer strT = new StringTokenizer(stepping, "/");
int count = strT.countTokens();
if (count >= propCount) {
/* return from root */
return property;
} else {
/* append the tokens up to the token difference */
count = propCount - count;
StringBuffer result = new StringBuffer();
for (int i = 0; i < count; i++) {
result.append(proT.nextToken());
result.append('.');
}
result.append(property);
/* parent reference will have a dot on the end. Leave it off */
if (result.charAt(result.length()-1) == '.') {
return result.substring(0,result.length()-1);
} else {
return result.toString();
}
}
}
}
}
Maurice Nicholson
Java Developer
Opodo Limited
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