Creating new nodes with XML::DOM?

I'm trying to do some XML transformation using XML: Smiley Very Happy

OM, and while I've figure out how to create source/target XML: Smiley Very Happy

OM [document] objects; get a handle on the root node for each document; and get node information from the source document -- I'm having problems figuring out how to create new nodes in the new document. I have a feeling it's something "simple" that I'm missing - but...well...I'm missing it.

Here's some [simplified] sample code demonstrating my sitation:

Original structure: <record>
<name>
<last>...</last>
<first>...</first>
</name>
<address_info>
<address_line1>...</address_line1>
<address_line2>...</address_line2>
<city>...</city>
<state>...</state>
<zip>...</zip>
</address_info>
</record>
New Structure: <users>
<user>
<last>...</last>
<first>...</first>
<address>
<address_line1>...</address_line1>
<address_line2>...</address_line2>
<city>...</city>
<state>...</state>
<zip>...</zip>
</address>
</user>
</users>
Sample / Simplified Code: ...
use TeamSite:CRnode;
use XML:OM;
...
my $old_root = q{}
eval{ $old_root = TeamSite:CRnode->new(read_file($infile)); };
handle_error($@) if ($@);

my $old_xml = $old_root->get_xml(); # transform "iwov" to "xml" format shown above
my $old_root_elem = 'record';
my $old_dom = XML:OM:arser->new();
my $old_doc = q{};
eval{ $old_doc = $old_dom->parse($old_xml); };
handle_error($@) if ($@);

my $new_xml = qq[<users></users>];
my $new_root_elem = 'users';
my $new_dom = XML:OM:arser->new();
my $new_doc = q{}
eval { $new_doc = new_dom->parse($new_xml); };
handle_error($@) if ($@);

my $old_rootnode = ($old_doc->getElementsByTagName($old_root_elem))[0];
my $new_rootnode = ($new_doc->getElementsByTagName($new_root_elem))[0];

# so far, I believe all is okay

my $old_nodes = $old_rootnode->getChildNodes();
foreach my $node (@$nodes){
my $old_xpath = $old_rootnode.'.'.$node->getNodeName;
my $new_xpath = map_xpath($old_xpath);
# e.g.:
# old_xpath => record.name
# new_xpath => users.user
#=# (Q)
}
...

Q: How do I create a new node ('user') as a child node of the new document / new root node ('users')?

If I clone the existing node from the source doc and try to add it with:

$new_rootnode->insertBefore($cloned_node, undef);

I get an error about the cloned node having a different source document

I don't see any method for creating a new node in any of the XML: Smiley Very Happy

OM::* perldoc's I've looked at - did I miss one?

--fish
Senior Consultant, Quotient Inc.
http://www.quotient-inc.com

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Comments

Adam Stoller

I think I figured it out - not quite what I was thinking of as "simple" but not overly complex either:...
my $newnode = create_node($current_node, $new_node_name);
...
sub create_node{
my($node, $elem) = @_;
my $newnode = $node->cloneNode(0);
$newnode->setTagName($elem);
$node->insertBefore($newnode,undef);
return $newnode;
}
...The trick being to clone the existing node in the new document, then insert it as a child of the existing node after changing its name.
Now hopefully this will get me through the rest of my coding ....

--fish
Senior Consultant, Quotient Inc.
http://www.quotient-inc.com

Bill Klish

Looking at some Java XML DOM parsing code I wrote a while back, I see that I did this using a method called importNode. I did a quick check but I don't see that method in the Perl XML: Smiley Very Happy

OM:

ocument module documentation. That might only be a Java thing.

The other way I have seen this is to remove the node from one of the xml documents and then add that removed node to the new document. I remember this being a painful thing.

Probably to late to help,
-Bill

Adam Stoller

The create_node routine I came up with seems to do the trick.
Now... if I can get the rest of the logic working I'll be set ... ;-)

--fish
Senior Consultant, Quotient Inc.
http://www.quotient-inc.com

rodigz

weird getting this error.

xml declaration not at start of external entity at line 2, column 0, byte 1 at d:\iwhome\iw-perl\vendor\lib/XML/Parser
187

Johnny

I would avoid using XML: Smiley Very Happy

OM in PERL. If this is related to content it can play nasty games. The version of XML: Smiley Very Happy

OM that is shipped with teamsite has some utf8 encoding issues that can break double byte characters. If you are managing XML documents that may have high order utf8 characters I would suggest you avoid XML: Smiley Very Happy

OM... TeamSite: Smiley Very Happy

CRnode is clean enough for most of my tasks.