[jdom-interest] Parents - why do we need them?

[Noam Tamim]

> >That's the whole idea of "Shared"; my target was definitely not memory
> >optimization, but the ability to change the attributes of many elements
with
> >a single call. Another approach could be to use an Attribute that uses a
> >StringBuffer for the value, and exposes it - so I can use the same
> >StringBuffer for many Attributes, and change it later.
> That might be the most graceful of the possibilities, since it would
> provide a fairly trivial way to implement copy-on-write as well, for
> those who want that.  Feel like implementing an example?

Here:
===
import org.jdom.*;
import org.jdom.output.*;

public class SBAttribute extends Attribute {
 protected StringBuffer value;

 public SBAttribute(String name, StringBuffer value, Namespace ns) {
  super(); // avoid setting the original String value.
  setName(name);
  setValue(value);
  setNamespace(ns);
 }

 public SBAttribute(String name, StringBuffer value) {
  this(name,value,Namespace.NO_NAMESPACE);
 }

 // return the actual StringBuffer used by this attribute.
 public StringBuffer getBuffer() {
  return value;
 }

 public String getValue() {
  return value.toString();
 }

 public Attribute setValue(String value) {
  return setValue(new StringBuffer(value));
 }

 public SBAttribute setValue(StringBuffer value) {
  // here should probably come some verifications.
  this.value=value;
  return this;
 }
}
===


And here's an example of using it:
void main() throws IOException {
  Element root=new Element("root");
  StringBuffer name=new StringBuffer("noam");
  root.addContent(new Element("user").setAttribute(new
SBAttribute("name",name)));
  root.addContent(new Element("user").setAttribute(new
SBAttribute("name",name)));
  root.addContent(new Element("user").setAttribute(new
SBAttribute("name",name)));
  Document doc=new Document(root);

  XMLOutputter xout=new XMLOutputter("  ",true);

  System.out.println("name="+name);
  xout.output(doc,System.out);

  name.reverse();
  System.out.println("name="+name);
  xout.output(doc,System.out);
}


Now, I'm really not sure this is the correct way to go; I was just throwing
an idea, to see what people think of it. I'm not even sure there's use to
it.


 - Noam.