XML::LibXML::Node(3) User Contributed Perl Documentation XML::LibXML::Node(3)NAMEXML::LibXML::Node - Abstract Base Class of XML::LibXML Nodes
SYNOPSIS
$name = $node->nodeName;
$node->setNodeName( $newName );
$bool = $node->isSameNode( $other_node );
$bool = $node->isEqual( $other_node );
$content = $node->nodeValue;
$content = $node->textContent;
$lineno = $node->line_number();
$type = $node->nodeType;
$lineno = $node->line_number();
$node->unbindNode()
$childnode = $node->removeChild( $childnode )
$oldnode = $node->replaceChild( $newNode, $oldNode )
$node->replaceNode($newNode);
$childnode = $node->appendChild( $childnode );
$childnode = $node->addChild( $chilnode );
$node = $parent->addNewChild( $nsURI, $name );
$node->addSibling($newNode);
$newnode =$node->cloneNode( $deep )
$parentnode = $node->parentNode;
$nextnode = $node->nextSibling()
$prevnode = $node->previousSibling()
$boolean = $node->hasChildNodes();
$childnode = $node->firstChild;
$childnode = $node->lastChild;
$documentnode = $node->ownerDocument;
$node = $node->getOwner;
$node->setOwnerDocument( $doc );
$node->insertBefore( $newNode, $refNode )
$node->insertAfter( $newNode, $refNode )
@nodes = $node->findnodes( $xpath_statement );
$result = $node->find( $xpath );
print $node->findvalue( $xpath );
@childnodes = $node->childNodes;
$xmlstring = $node->toString($format,$docencoding);
$c14nstring = $node->toString($with_comments, $xpath_expression);
$str = $doc->serialze($format);
$c14nstr = $doc->serialize_c14n($comment_flag,$xpath);
$localname = $node->localname;
$nameprefix = $node->prefix;
$uri = $node->namespaceURI()
$boolean = $node->hasAttributes();
@attributelist = $node->attributes();
$URI = $node->lookupNamespaceURI( $prefix );
$prefix = $node->lookupNamespacePrefix( $URI );
$iter = $node->iterator;
$node->normalize;
@nslist = $node->getNamespaces;
$node->removeChildNodes();
DESCRIPTIONXML::LibXML::Node defines functions that are common to all Node Types.
A LibXML::Node should never be created standalone, but as an instance
of a high level class such as LibXML::Element or LibXML::Text. The
class itself should provide only common functionality. In XML::LibXML
each node is part either of a document or a document-fragment. Because
of this there is no node without a parent. This may causes confusion
with "unbound" nodes.
nodeName
$name = $node->nodeName;
Returns the node's name. This Function is aware of namesaces and
returns the full name of the current node (prefix:localname)
setNodeName
$node->setNodeName( $newName );
In very limited situations, it is useful to change a nodes name. In
the DOM specification this should throw an error. This Function is
aware of namespaces.
isSameNode
$bool = $node->isSameNode( $other_node );
returns TRUE (1) if the given nodes refer to the same node
structure, otherwise FALSE (0) is returned.
isEqual
$bool = $node->isEqual( $other_node );
deprecated version of isSameNode().
NOTE isEqual will change behaviour to follow the DOM specification
nodeValue
$content = $node->nodeValue;
If the node has any content (such as stored in a text node) it can
get requested through this function.
NOTE: Element Nodes have no content per definition. To get the text
value of an Element use textContent() instead!
textContent
$content = $node->textContent;
this function returns the content of all text nodes in the
descendants of the given node as spacified in DOM.
line_number
$lineno = $node->line_number();
This function returns the line number where the tag was found
during parsing. If a node is added to the document the line number
is 0. Problems may occour, if a node from one document is passed to
another one.
Note: line_number() is special to XML::LibXML and not part of the
DOM specification.
If the line_numbers flag of the parser was not activated before
parsing, line_number() will always return 0.
nodeType
$type = $node->nodeType;
Retrun the node's type. The possible types are described in the
libxml2 tree.h documentation. The return value of this function is
a numeric value. Therefore it differs from the result of perl ref
function.
line_number
$lineno = $node->line_number();
This function returns the line number where the tag was found
during parsing. If a node is added to the document the line number
is 0. Problems may occur, if a node from one document is passed to
another one.
Note: line_number() is special to XML::LibXML and not part of the
DOM specification.
If the line_numbers flag of the parser was not activated before
parsing, line_number() will always return 0.
unbindNode
$node->unbindNode()
Unbinds the Node from its siblings and Parent, but not from the
Document it belongs to. If the node is not inserted into the DOM
afterwards it will be lost after the programm terminated. From a
low level view, the unbound node is stripped from the context it is
and inserted into a (hidden) document-fragment.
removeChild
$childnode = $node->removeChild( $childnode )
This will unbind the Child Node from its parent $node. The function
returns the unbound node. If oldNode is not a child of the given
Node the function will fail.
replaceChild
$oldnode = $node->replaceChild( $newNode, $oldNode )
Replaces the $oldNode with the $newNode. The $oldNode will be
unbound from the Node. This function differs from the DOM L2
specification, in the case, if the new node is not part of the
document, the node will be imported first.
replaceNode
$node->replaceNode($newNode);
This function is very similar to replaceChild(), but it replaces
the node itself rather than a childnode. This is useful if a node
found by any XPath function, should be replaced.
appendChild
$childnode = $node->appendChild( $childnode );
The function will add the $childnode to the end of $node's
children. The function should fail, if the new childnode is
allready a child of $node. This function differs from the DOM L2
specification, in the case, if the new node is not part of the
document, the node will be imported first.
addChild
$childnode = $node->addChild( $chilnode );
As an alternative to appendChild() one can use the addChild()
function. This function is a bit faster, because it avoids all DOM
conformity checks. Therefore this function is quite useful if one
builds XML documents in memory where the order and ownership
(ownerDocument) is assured.
addChild() uses libxml2's own xmlAddChild() function. Thus it has
to be used with extra care: If a text node is added to a node and
the node itself or its last childnode is as well a text node, the
node to add will be merged with the one already available. The
current node will be removed from memory after this action. Because
perl is not aware of this action, the perl instance is still
available. XML::LibXML will catch the loss of a node and refuse to
run any function called on that node.
my $t1 = $doc->createTextNode( "foo" );
my $t2 = $doc->createTextNode( "bar" );
$t1->addChild( $t2 ); # is ok
my $val = $t2->nodeValue(); # will fail, script dies
Also addChild() will not check it the added node belongs to the
same document as the node it will be added to. This could lead to
inconsistent documents and in more worse cases even to memory
violations, if one does not keep track of this issue.
Although this sounds like a lot of trouble, addChild() is useful if
a document is built from a stream, such as happens sometimes in SAX
handlers or filters.
If you are not sure about the source of your nodes, you better stay
with appendChild(), because this function is more user friendly in
the sense of being more error tolerant.
addNewChild
$node = $parent->addNewChild( $nsURI, $name );
Similar to addChild(), this function uses low level libxml2
functionality to provide faster interface for DOM building.
addNewChild() uses xmlNewChild() to create a new node on a given
parent element.
addNewChild() has two parameters $nsURI and $name, where $nsURI is
an (optional) namespace URI. $name is the fully qualified element
name; addNewChild() will determine the correct prefix if nessecary.
The function returns the newly created node.
This function is very useful for DOM building, where a created node
can be directly associated with its parent. NOTE this function is
not part of the DOM specification and its use will limit your code
to XML::LibXML.
addSibling
$node->addSibling($newNode);
addSibling() allows adding an additional node to the end of a
nodelist, defined by the given node.
cloneNode
$newnode =$node->cloneNode( $deep )
cloneNode creates a copy of $node. When $deep is set to 1 (true)
the function will copy all childnodes as well. If $deep is 0 only
the current node will be copied.
cloneNode will not copy any namespace information if it is not run
recursivly.
parentNode
$parentnode = $node->parentNode;
Returns simply the Parent Node of the current node.
nextSibling
$nextnode = $node->nextSibling()
Returns the next sibling if any .
previousSibling
$prevnode = $node->previousSibling()
Analogous to getNextSibling the function returns the previous
sibling if any.
hasChildNodes
$boolean = $node->hasChildNodes();
If the current node has Childnodes this function returns TRUE (1),
otherwise it returns FALSE (0, not undef).
firstChild
$childnode = $node->firstChild;
If a node has childnodes this function will return the first node
in the childlist.
lastChild
$childnode = $node->lastChild;
If the $node has childnodes this function returns the last child
node.
ownerDocument
$documentnode = $node->ownerDocument;
Through this function it is always possible to access the document
the current node is bound to.
getOwner
$node = $node->getOwner;
This function returns the node the current node is associated with.
In most cases this will be a document node or a document fragment
node.
setOwnerDocument
$node->setOwnerDocument( $doc );
This function binds a node to another DOM. This method unbinds the
node first, if it is allready bound to another document.
This function is the oposite calling of XML::LibXML::Document's
adoptNode() function. Because of this it has the same limitations
with Entity References as adoptNode().
insertBefore
$node->insertBefore( $newNode, $refNode )
The method inserts $newNode before $refNode. If $refNode is
undefined, the newNode will be set as the new last child of the
parent node. This function differs from the DOM L2 specification,
in the case, if the new node is not part of the document, the node
will be imported first, automatically.
$refNode has to be passed to the function even if it is undefined:
$node->insertBefore( $newNode, undef ); # the same as $node->appendChild( $newNode );
$node->insertBefore( $newNode ); # wrong
Note, that the reference node has to be a direct child of the node
the function is called on. Also, $newChild is not allowed to be an
ancestor of the new parent node.
insertAfter
$node->insertAfter( $newNode, $refNode )
The method inserts $newNode after $refNode. If $refNode is
undefined, the newNode will be set as the new last child of the
parent node.
Note, that $refNode has to be passed explicitly even if it is
undef.
findnodes
@nodes = $node->findnodes( $xpath_statement );
findnodes performs the xpath statement on the current node and
returns the result as an array. In scalar context returns a
XML::LibXML::NodeList object.
find
$result = $node->find( $xpath );
find performs the xpath expression using the current node as the
context of the expression, and returns the result depending on what
type of result the XPath expression had. For example, the XPath "1
* 3 + 52" results in a XML::LibXML::Number object being returned.
Other expressions might return a XML::LibXML::Boolean object, or a
XML::LibXML::Literal object (a string). Each of those objects uses
Perl's overload feature to "do the right thing" in different
contexts.
findvalue
print $node->findvalue( $xpath );
findvalue is exactly equivalent to:
$node->find( $xpath )->to_literal;
That is, it returns the literal value of the results. This enables
you to ensure that you get a string back from your search, allowing
certain shortcuts. This could be used as the equivalent of XSLT's
<xsl:value-of select="some_xpath"/>.
childNodes
@childnodes = $node->childNodes;
getChildnodes implements a more intuitive interface to the
childnodes of the current node. It enables you to pass all children
directly to a map or grep. If this function is called in scalar
context, a XML::LibXML::NodeList object will be returned.
toString
$xmlstring = $node->toString($format,$docencoding);
This is the equivalent to XML::LibXML::Document::toString for a
single node. This means a node and all its childnodes will be
dumped into the result string.
Additionally to the $format flag of XML::LibXML::Document, this
version accepts the optional $docencoding flag. If this flag is set
this function returns the string in its original encoding (the
encoding of the document) rather than UTF8.
toStringC14N
$c14nstring = $node->toString($with_comments, $xpath_expression);
The function is similar to toString(). Instead of simply
serializing the document tree, it transforms it as it is specified
in the XML-C14N Specification. Such transformation is known as
canonization.
If $with_comments is 0 or not defined, the result-document will not
contain any comments that exist in the original document. To
include comments into the canonized document, $with_comments has to
be set to 1.
The parameter $xpath_expression defines the nodeset of nodes that
should be visible in the resulting document. This can be used to
filter out some nodes. One has to note, that only the nodes that
are part of the nodeset, will be included into the result-document.
Their child-nodes will not exist in the resulting document, unless
they are part of the nodeset defined by the xpath expression.
If $xpath_expression is ommitted or empty, toStringC14N() will
include all nodes in the given sub-tree.
No serializing flags will be recognized by this function!
serialize
$str = $doc->serialze($format);
Alternative form of toString(). This function name added to be more
conform with libxml2's examples.
serialize_c14n
$c14nstr = $doc->serialize_c14n($comment_flag,$xpath);
Alternative form of toStringC14N().
localname
$localname = $node->localname;
Returns the local name of a tag. This is the part behind the colon.
prefix
$nameprefix = $node->prefix;
Returns the prefix of a tag. This is the part before the colon.
namespaceURI
$uri = $node->namespaceURI()
returns the URI of the current namespace.
hasAttributes
$boolean = $node->hasAttributes();
returns 1 (TRUE) if the current node has any attributes set,
otherwise 0 (FALSE) is returned.
attributes
@attributelist = $node->attributes();
This function returns all attributes and namespace declarations
assigned to the given node.
Because XML::LibXML does not implement namespace declarations and
attributes the same way, it is required to test what kind of node
is handled while accessing the functions result.
If this function is called in array context the attribute nodes are
returned as an array. In scalar context the function will return a
XML::LibXML::NamedNodeMap object.
lookupNamespaceURI
$URI = $node->lookupNamespaceURI( $prefix );
Find a namespace URI by its prefix starting at the current node.
lookupNamespacePrefix
$prefix = $node->lookupNamespacePrefix( $URI );
Find a namespace prefix by its URI starting at the current node.
NOTE Only the namespace URIs are meant to be unique. The prefix is
only document related. Also the document might have more than a
single prefix defined for a namespace.
iterator
$iter = $node->iterator;
This function is deprecated since XML::LibXML 1.54. It is only a
dummy function that will get removed entirely in one of the next
versions.
To make use of iterator functions use XML::LibXML::Iterator Module
available on CPAN.
normalize
$node->normalize;
This function normalizes adjacent textnodes. This function is not
as strict as libxml2's xmlTextMerge() function, since it will not
free a node that is still referenced by the perl layer.
getNamespaces
@nslist = $node->getNamespaces;
If a node has any namespaces defined, this function will return
these namespaces. Note, that this will not return all namespaces
that are in scope, but only the ones declared explicitly for that
node.
Although getNamespaces is available for all nodes, it only makes
sense if used with element nodes.
removeChildNodes
$node->removeChildNodes();
This function is not specified for any DOM level: It removes all
childnodes from a node in a single step. Other than the libxml2
function itself (xmlFreeNodeList), this function will not
immediately remove the nodes from the memory. This saves one from
getting memory violations, if there are nodes still referred to
from the Perl level.
AUTHORS
Matt Sergeant, Christian Glahn, =head1 VERSION
1.58
COPYRIGHT
2001-2004, AxKit.com Ltd; 2002-2004 Christian Glahn, All rights
reserved.
perl v5.10.0 2004-03-31 XML::LibXML::Node(3)
