xml4c child nodes

[marfi95]

I'm trying to iterate through a list of child nodes. It seems like to
get the text value of the node, you have to do a
node->getFirstChild( )->getNodeValue . This being said, there is a
hasChildNodes method, but if I use that, it includes the "text" nodes
also, which I don't want ot include.

if this is my xml:

<A>
<B></B>
<C></C>
</A>

if I have a node for B, I thought getNextSibling would return C, but it
didn't. it returned #text.

confused.

[marfi95]

Martin Honnen wrote:

ma*****@yahoo.c om wrote:

But can someone please explain the difference
between a DOM_Node and a DOM_Element. Is a DOM_Element just a "type"
of DOM_Node ?

Yes, node is usually an abstract base class (or interface) that is
extended by several concrete sub classes (or interfaces) (e.g. for
document, element, attribute, text, processing instruction, cdata
section, comment nodes).

What I did was a getElementsByTa gName for the DOM_Document to give me a
NodeList, then for each of those nodes, I was going to use a
getElementsByTa g to get the child elemnentnodes(" *").length to
determine if that node has any child elements, but can't because
getElementsByTa gname is not part of DOM_Node, but DOM_Element. What is
the correct way of doing this please ? I'm new to DOM as you can see.

You need to cast that DOM_Node that you have to a DOM_Element. With Java
you would simply do e.g.
Element el = (Element)node;
Can't help with exact xml4c syntax.

--

Martin Honnen
http://JavaScript.FAQTs.com/

Thanks. I got it.

[marfi95]

ma*****@yahoo.c om wrote:

Martin Honnen wrote:

ma*****@yahoo.c om wrote:

But can someone please explain the difference
between a DOM_Node and a DOM_Element. Is a DOM_Element just a "type"
of DOM_Node ?

Yes, node is usually an abstract base class (or interface) that is
extended by several concrete sub classes (or interfaces) (e.g. for
document, element, attribute, text, processing instruction, cdata
section, comment nodes).

What I did was a getElementsByTa gName for the DOM_Document to give me a
NodeList, then for each of those nodes, I was going to use a
getElementsByTa g to get the child elemnentnodes(" *").length to
determine if that node has any child elements, but can't because
getElementsByTa gname is not part of DOM_Node, but DOM_Element. What is
the correct way of doing this please ? I'm new to DOM as you can see.

You need to cast that DOM_Node that you have to a DOM_Element. With Java
you would simply do e.g.
Element el = (Element)node;
Can't help with exact xml4c syntax.

--

Martin Honnen
http://JavaScript.FAQTs.com/

Thanks. I got it.

Since getElementsByTa g("*") returns all element nodes, is there an easy
way to only get the next level of elements.

i.e.
<A>
<B>
<C>
</C>
</B>
<B>
<C>
</C>
</B>
</A>

I would only want the NodeList returned to contain the B's element
nodes (and not C's)

Thanks.

[Joseph Kesselman]

ma*****@yahoo.c om wrote:

Since getElementsByTa g("*") returns all element nodes, is there an easy
way to only get the next level of elements.

Simplest: getFirstChild followed by repeated getNextSibling, ignoring
those which aren't elements.

Overkill: Use one of the mechanisms in the DOM Level 2 Traversal
feature, setting its filters to show you only the nodes you're
interested in.

--
Joe Kesselman / Beware the fury of a patient man. -- John Dryden

[marfi95]

Joseph Kesselman wrote:

ma*****@yahoo.c om wrote:

Since getElementsByTa g("*") returns all element nodes, is there an easy
way to only get the next level of elements.

Simplest: getFirstChild followed by repeated getNextSibling, ignoring
those which aren't elements.

Overkill: Use one of the mechanisms in the DOM Level 2 Traversal
feature, setting its filters to show you only the nodes you're
interested in.

--
Joe Kesselman / Beware the fury of a patient man. -- John Dryden

Thanks. I've heard that using DOM can be very memory intensive because
of the tree and it might not be the best approach on "large" XML
documents. Does anyone have any numbers on what large would be and
where it might not be the appropriate method to use.

The XML we're talking about here could be around 30-40K, with about
1000 simultaneous users. Each thread would have their own parser
instance, which based on my understanding of what I've been reading,
that shouldn't be an issue. But I'm a little concerned over what I'm
reading about the memory usage.

Any ideas what kind of sizes we're talking about here ?

[Joseph Kesselman]

See http://www.w3.org/DOM/faq.html#SAXandDOM

The DOM is only an API; if you want to talk about memory usage, you need
to discuss specific implementations , especially since the storage behind
that API doesn't necessarily use the same structure as that presented to
the user.