Hi Michael,
Here is my formatXmlAsString method formatted for brevity:
public static String formatXmlAsString(Document doc) {
StringWriter out = new StringWriter();
TransformerFactory factory = TransformerFactory.newInstance();
factory.setAttribute("indent-number", new Integer(2));
Transformer serializer;
serializer = factory.newTransformer();
serializer.setOutputProperty(OutputKeys.INDENT, "yes");
serializer.setOutputProperty("{http://xml.apache.org/
xslt}indent-amount", "4");
serializer.transform(new DOMSource(doc), new
StreamResult(out));
return out.toString();
}
Here I tried appending a blank text node, and I can see in the DOM
that the text node _is_ there, but it still gets squashed upon output:
DocumentBuilderFactory dbf =
DocumentBuilderFactory.newInstance();
DocumentBuilder db = dbf.newDocumentBuilder();
Document d = db.newDocument();
Element root = d.createElement("root");
Element tag = d.createElement("tag");
d.appendChild(root);
root.appendChild(tag);
System.out.println("Child nodes? " +
tag.getChildNodes().item(0));
System.out.println("Child nodes l? " +
tag.getChildNodes().getLength());
Text text = d.createTextNode("");
tag.appendChild(text);
System.out.println("Child nodes? " +
tag.getChildNodes().item(0));
System.out.println("Child nodes l? " +
tag.getChildNodes().getLength());
System.out.println(formatXmlAsString(d));
Child nodes? null
Child nodes l? 0
Child nodes? [#text: ]
Child nodes l? 1
<?xml version="1.0" encoding="UTF-8"?>
<root>
<tag/>
</root>
On Dec 15, 2008, at 3:29 PM, Michael Glavassevich wrote:
To add to what I said ...
I think it's likely the case that the Xerces/Xalan serializer will
write <tag></tag> if you attach an empty text node to the element.
You should keep in mind that this is an implementation detail that
could change in the future. Perhaps one day it will write <tag/>
instead.
Thanks.
Michael Glavassevich
XML Parser Development
IBM Toronto Lab
E-mail: mrgla...@ca.ibm.com
E-mail: mrgla...@apache.org
Michael Glavassevich/Toronto/i...@ibmca wrote on 12/15/2008 03:20:57
PM:
> Hi Ian,
>
> I've never heard of XmlUtils.formatXmlAsString. It's certainly not
> distributed with Xerces. Have you tried one of the standard
> serialization methods [1] from JAXP or DOM Level 3?
>
> Thanks.
>
> [1] http://xerces.apache.org/xerces2-j/faq-general.html#faq-6
>
> Michael Glavassevich
> XML Parser Development
> IBM Toronto Lab
> E-mail: mrgla...@ca.ibm.com
> E-mail: mrgla...@apache.org
>
> Ian Hummel <hum...@parityinc.net> wrote on 12/15/2008 03:08:49 PM:
>
> > Hi Michael,
> >
> > I know <tag></tag> and <tag/> are the same, but unfortunately the
> > buggy-parser-that-cannot-be-changed on the other end doesn't :)
> >
> > DocumentBuilder db = dbf.newDocumentBuilder();
> > Document d = db.newDocument();
> > Element root = d.createElement("root");
> > Element tag = d.createElement("tag");
> > tag.setTextContent("");
> > d.appendChild(root);
> > root.appendChild(tag);
> > System.out.println(XmlUtils.formatXmlAsString(d));
> >
> > This always outputs <tag/> and never <tag></tag> like I need it
to.
> >
> > - Ian.
> >
> > On Dec 12, 2008, at 10:33 PM, Michael Glavassevich wrote:
> >
> > Hi Ian,
> >
> > > I need to create XML that looks like this whenever the value of
> > > "tag" is "" (the empty string):
> > >
> > > <root>
> > > <tag></tag>
> > > </root>
> >
> > Why? <tag/> and <tag></tag> have the same meaning. Whichever
form is
> > chosen by the serializer should have no significance.
> >
> > > I am more concerned in preserving the empty text node when I
> > > serialize to e.g. a file... not so much the parsing.
> > >
> > > Any one else have any ideas?
> >
> > Would help if you showed your code for serializing the document.
> >
> > > Are blank text nodes like that invalid XML or something?
> >
> > In the snippet you posted you created a text node with the '\t'
> > (tab) character in it. That isn't "blank" or empty.
> >
> > Thanks.
> >
> > Michael Glavassevich
> > XML Parser Development
> > IBM Toronto Lab
> > E-mail: mrgla...@ca.ibm.com
> > E-mail: mrgla...@apache.org
> >
> > Ian Hummel <hum...@parityinc.net> wrote on 12/12/2008 09:21:47 AM:
> >
> > > Hi, I didn't really understand how that's going to help.
> > >
> > > I am more concerned in preserving the empty text node when I
> > > serialize to e.g. a file... not so much the parsing.
> > >
> > > Any one else have any ideas? Are blank text nodes like that
invalid
> > > XML or something?
> > >
> > > On Dec 11, 2008, at 11:53 AM, ravika...@gmail.com wrote:
> > >
> > > Hi Lan,
> > >
> > > I think we can Implement by LSParser Interface. http://java.sun.
> > > com/j2se/1.5.0/docs/api/org/w3c/dom/ls/LSParser.html
> > > this link may help you.
> > >
> > > Regards,
> > > Ravikanth
> >
> > > On Thu, Dec 11, 2008 at 7:36 PM, Ian Hummel <hum...@parityinc.net
> wrote:
> > > Hi everyone,
> > >
> > > I need to create XML that looks like this whenever the value of
> > > "tag" is "" (the empty string):
> > >
> > > <root>
> > > <tag></tag>
> > > </root>
> > >
> > > I've tried the following:
> > >
> > > DocumentBuilderFactory dbf =
DocumentBuilderFactory.newInstance();
> > > DocumentBuilder db = dbf.newDocumentBuilder();
> > > Document d = db.newDocument();
> > > Element root = d.createElement("root");
> > > Element tag = d.createElement("tag");
> > > d.appendChild(root);
> > > root.appendChild(tag);
> > > Text text = d.createTextNode("\t");
> > > tag.appendChild(text);
> > >
> > > but I always end up with XML like this:
> > >
> > > <root>
> > > <tag/>
> > > </root>
> > >
> > > Is there a way to force empty text nodes to get "denormalized" ?
> > >
> > > Thanks,
> > >
> > > Ian.
> > >
> > > --
> > > Ravikanth
