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XML::LibXML::Document(3)             User Contributed Perl Documentation            XML::LibXML::Document(3)



NAME
       XML::LibXML::Document - XML::LibXML DOM Document Class

SYNOPSIS
         use XML::LibXML;
         # Only methods specific to Document nodes are listed here,
         # see XML::LibXML::Node manpage for other methods

         $dom = XML::LibXML::Document->new( $version, $encoding );
         $dom = XML::LibXML::Document->createDocument( $version, $encoding );
         $strURI = $doc->URI();
         $doc->setURI($strURI);
         $strEncoding = $doc->encoding();
         $strEncoding = $doc->actualEncoding();
         $doc->setEncoding($new_encoding);
         $strVersion = $doc->version();
         $doc->standalone
         $doc->setStandalone($numvalue);
         my $compression = $doc->compression;
         $doc->setCompression($ziplevel);
         $docstring = $dom->toString($format);
         $c14nstr = $doc->toStringC14N($comment_flag, $xpath [, $xpath_context ]);
         $ec14nstr = $doc->toStringEC14N($comment_flag, $xpath [, $xpath_context ], $inclusive_prefix_list);
         $str = $doc->serialize($format);
         $state = $doc->toFile($filename, $format);
         $state = $doc->toFH($fh, $format);
         $str = $document->toStringHTML();
         $str = $document->serialize_html();
         $bool = $dom->is_valid();
         $dom->validate();
         $root = $dom->documentElement();
         $dom->setDocumentElement( $root );
         $element = $dom->createElement( $nodename );
         $element = $dom->createElementNS( $namespaceURI, $qname );
         $text = $dom->createTextNode( $content_text );
         $comment = $dom->createComment( $comment_text );
         $attrnode = $doc->createAttribute($name [,$value]);
         $attrnode = $doc->createAttributeNS( namespaceURI, $name [,$value] );
         $fragment = $doc->createDocumentFragment();
         $cdata = $dom->createCDATASection( $cdata_content );
         my $pi = $doc->createProcessingInstruction( $target, $data );
         my $entref = $doc->createEntityReference($refname);
         $dtd = $document->createInternalSubset( $rootnode, $public, $system);
         $dtd = $document->createExternalSubset( $rootnode_name, $publicId, $systemId);
         $document->importNode( $node );
         $document->adoptNode( $node );
         my $dtd = $doc->externalSubset;
         my $dtd = $doc->internalSubset;
         $doc->setExternalSubset($dtd);
         $doc->setInternalSubset($dtd);
         my $dtd = $doc->removeExternalSubset();
         my $dtd = $doc->removeInternalSubset();
         my @nodelist = $doc->getElementsByTagName($tagname);
         my @nodelist = $doc->getElementsByTagNameNS($nsURI,$tagname);
         my @nodelist = $doc->getElementsByLocalName($localname);
         my $node = $doc->getElementById($id);
         $dom->indexElements();

DESCRIPTION
       The Document Class is in most cases the result of a parsing process. But sometimes it is necessary to
       create a Document from scratch. The DOM Document Class provides functions that conform to the DOM
       Core naming style.

       It inherits all functions from XML::LibXML::Node as specified in the DOM specification. This enables
       access to the nodes besides the root element on document level - a "DTD" for example. The support for
       these nodes is limited at the moment.

       While generally nodes are bound to a document in the DOM concept it is suggested that one should
       always create a node not bound to any document. There is no need of really including the node to the
       document, but once the node is bound to a document, it is quite safe that all strings have the
       correct encoding. If an unbound text node with an ISO encoded string is created (e.g.  with
       $CLASS->new()), the "toString" function may not return the expected result.

       To prevent such problems, it is recommended to pass all data to XML::LibXML methods as character
       strings (i.e. UTF-8 encoded, with the UTF8 flag on).

METHODS
       Many functions listed here are extensively documented in the DOM Level 3 specification
       (http://www.w3.org/TR/DOM-Level-3-Core/ <http://www.w3.org/TR/DOM-Level-3-Core/>). Please refer to
       the specification for extensive documentation.

       new
             $dom = XML::LibXML::Document->new( $version, $encoding );

           alias for createDocument()

       createDocument
             $dom = XML::LibXML::Document->createDocument( $version, $encoding );

           The constructor for the document class. As Parameter it takes the version string and (optionally)
           the encoding string. Simply calling createDocument() will create the document:

             <?xml version="your version" encoding="your encoding"?>

           Both parameter are optional. The default value for $version is 1.0, of course. If the $encoding
           parameter is not set, the encoding will be left unset, which means UTF-8 is implied.

           The call of createDocument() without any parameter will result the following code:

             <?xml version="1.0"?>

           Alternatively one can call this constructor directly from the XML::LibXML class level, to avoid
           some typing. This will not have any effect on the class instance, which is always
           XML::LibXML::Document.

             my $document = XML::LibXML->createDocument( "1.0", "UTF-8" );

           is therefore a shortcut for

             my $document = XML::LibXML::Document->createDocument( "1.0", "UTF-8" );

       URI
             $strURI = $doc->URI();

           Returns the URI (or filename) of the original document. For documents obtained by parsing a
           string of a FH without using the URI parsing argument of the corresponding "parse_*" function,
           the result is a generated string unknown-XYZ where XYZ is some number; for documents created with
           the constructor "new", the URI is undefined.

           The value can be modified by calling "setURI" method on the document node.

       setURI
             $doc->setURI($strURI);

           Sets the URI of the document reported by the method URI (see also the URI argument to the various
           "parse_*" functions).

       encoding
             $strEncoding = $doc->encoding();

           returns the encoding string of the document.

             my $doc = XML::LibXML->createDocument( "1.0", "ISO-8859-15" );
             print $doc->encoding; # prints ISO-8859-15

       actualEncoding
             $strEncoding = $doc->actualEncoding();

           returns the encoding in which the XML will be returned by $doc->toString().  This is usually the
           original encoding of the document as declared in the XML declaration and returned by
           $doc->encoding. If the original encoding is not known (e.g. if created in memory or parsed from a
           XML without a declared encoding), 'UTF-8' is returned.

             my $doc = XML::LibXML->createDocument( "1.0", "ISO-8859-15" );
             print $doc->encoding; # prints ISO-8859-15

       setEncoding
             $doc->setEncoding($new_encoding);

           This method allows to change the declaration of encoding in the XML declaration of the document.
           The value also affects the encoding in which the document is serialized to XML by
           $doc->toString(). Use setEncoding() to remove the encoding declaration.

       version
             $strVersion = $doc->version();

           returns the version string of the document

           getVersion() is an alternative form of this function.

       standalone
             $doc->standalone

           This function returns the Numerical value of a documents XML declarations standalone attribute.
           It returns 1 if standalone="yes" was found, _ if standalone="no" was found and -1 if standalone
           was not specified (default on creation).

       setStandalone
             $doc->setStandalone($numvalue);

           Through this method it is possible to alter the value of a documents standalone attribute. Set it
           to 1 to set standalone="yes", to _ to set standalone="no" or set it to -1 to remove the
           standalone attribute from the XML declaration.

       compression
             my $compression = $doc->compression;

           libxml2 allows reading of documents directly from gzipped files. In this case the compression
           variable is set to the compression level of that file (0-8). If XML::LibXML parsed a different
           source or the file wasn't compressed, the returned value will be -1.

       setCompression
             $doc->setCompression($ziplevel);

           If one intends to write the document directly to a file, it is possible to set the compression
           level for a given document. This level can be in the range from 0 to 8. If XML::LibXML should not
           try to compress use -1 (default).

           Note that this feature will only work if libxml2 is compiled with zlib support and toFile() is
           used for output.

       toString
             $docstring = $dom->toString($format);

           toString is a DOM serializing function, so the DOM Tree is serialized into an XML string, ready
           for output.

           IMPORTANT: unlike toString for other nodes, on document nodes this function returns the XML as a
           byte string in the original encoding of the document (see the actualEncoding() method)! This
           means you can simply do:

             open my $out_fh, '>', $file;
             print {$out_fh} $doc->toString;

           regardless of the actual encoding of the document. See the section on encodings in XML::LibXML
           for more details.

           The optional $format parameter sets the indenting of the output. This parameter is expected to be
           an "integer" value, that specifies that indentation should be used. The format parameter can have
           three different values if it is used:

           If $format is 0, than the document is dumped as it was originally parsed

           If $format is 1, libxml2 will add ignorable white spaces, so the nodes content is easier to read.
           Existing text nodes will not be altered

           If $format is 2 (or higher), libxml2 will act as $format == 1 but it add a leading and a trailing
           line break to each text node.

           libxml2 uses a hard-coded indentation of 2 space characters per indentation level. This value can
           not be altered on run-time.

       toStringC14N
             $c14nstr = $doc->toStringC14N($comment_flag, $xpath [, $xpath_context ]);

           See the documentation in XML::LibXML::Node.

       toStringEC14N
             $ec14nstr = $doc->toStringEC14N($comment_flag, $xpath [, $xpath_context ], $inclusive_prefix_list);

           See the documentation in XML::LibXML::Node.

       serialize
             $str = $doc->serialize($format);

           An alias for toString(). This function was name added to be more consistent with libxml2.

       serialize_c14n
           An alias for toStringC14N().

       serialize_exc_c14n
           An alias for toStringEC14N().

       toFile
             $state = $doc->toFile($filename, $format);

           This function is similar to toString(), but it writes the document directly into a filesystem.
           This function is very useful, if one needs to store large documents.

           The format parameter has the same behaviour as in toString().

       toFH
             $state = $doc->toFH($fh, $format);

           This function is similar to toString(), but it writes the document directly to a filehandle or a
           stream. A byte stream in the document encoding is passed to the file handle. Do NOT apply any
           ":encoding(...)" or ":utf8" PerlIO layer to the filehandle! See the section on encodings in
           XML::LibXML for more details.

           The format parameter has the same behaviour as in toString().

       toStringHTML
             $str = $document->toStringHTML();

           toStringHTML serialize the tree to a byte string in the document encoding as HTML. With this
           method indenting is automatic and managed by libxml2 internally.

       serialize_html
             $str = $document->serialize_html();

           An alias for toStringHTML().

       is_valid
             $bool = $dom->is_valid();

           Returns either TRUE or FALSE depending on whether the DOM Tree is a valid Document or not.

           You may also pass in a XML::LibXML::Dtd object, to validate against an external DTD:

             if (!$dom->is_valid($dtd)) {
                  warn("document is not valid!");
              }

       validate
             $dom->validate();

           This is an exception throwing equivalent of is_valid. If the document is not valid it will throw
           an exception containing the error. This allows you much better error reporting than simply
           is_valid or not.

           Again, you may pass in a DTD object

       documentElement
             $root = $dom->documentElement();

           Returns the root element of the Document. A document can have just one root element to contain
           the documents data.

           Optionally one can use getDocumentElement.

       setDocumentElement
             $dom->setDocumentElement( $root );

           This function enables you to set the root element for a document. The function supports the
           import of a node from a different document tree, but does not support a document fragment as
           $root.

       createElement
             $element = $dom->createElement( $nodename );

           This function creates a new Element Node bound to the DOM with the name $nodename.

       createElementNS
             $element = $dom->createElementNS( $namespaceURI, $qname );

           This function creates a new Element Node bound to the DOM with the name $nodename and placed in
           the given namespace.

       createTextNode
             $text = $dom->createTextNode( $content_text );

           As an equivalent of createElement, but it creates a Text Node bound to the DOM.

       createComment
             $comment = $dom->createComment( $comment_text );

           As an equivalent of createElement, but it creates a Comment Node bound to the DOM.

       createAttribute
             $attrnode = $doc->createAttribute($name [,$value]);

           Creates a new Attribute node.

       createAttributeNS
             $attrnode = $doc->createAttributeNS( namespaceURI, $name [,$value] );

           Creates an Attribute bound to a namespace.

       createDocumentFragment
             $fragment = $doc->createDocumentFragment();

           This function creates a DocumentFragment.

       createCDATASection
             $cdata = $dom->createCDATASection( $cdata_content );

           Similar to createTextNode and createComment, this function creates a CDataSection bound to the
           current DOM.

       createProcessingInstruction
             my $pi = $doc->createProcessingInstruction( $target, $data );

           create a processing instruction node.

           Since this method is quite long one may use its short form createPI().

       createEntityReference
             my $entref = $doc->createEntityReference($refname);

           If a document has a DTD specified, one can create entity references by using this function. If
           one wants to add a entity reference to the document, this reference has to be created by this
           function.

           An entity reference is unique to a document and cannot be passed to other documents as other
           nodes can be passed.

           NOTE: A text content containing something that looks like an entity reference, will not be
           expanded to a real entity reference unless it is a predefined entity

             my $string = "&foo;";
              $some_element->appendText( $string );
              print $some_element->textContent; # prints "&amp;foo;"

       createInternalSubset
             $dtd = $document->createInternalSubset( $rootnode, $public, $system);

           This function creates and adds an internal subset to the given document.  Because the function
           automatically adds the DTD to the document there is no need to add the created node explicitly to
           the document.

             my $document = XML::LibXML::Document->new();
              my $dtd      = $document->createInternalSubset( "foo", undef, "foo.dtd" );

           will result in the following XML document:

             <?xml version="1.0"?>
              <!DOCTYPE foo SYSTEM "foo.dtd">

           By setting the public parameter it is possible to set PUBLIC DTDs to a given document. So

             my $document = XML::LibXML::Document->new();
             my $dtd      = $document->createInternalSubset( "foo", "-//FOO//DTD FOO 0.1//EN", undef );

           will cause the following declaration to be created on the document:

             <?xml version="1.0"?>
             <!DOCTYPE foo PUBLIC "-//FOO//DTD FOO 0.1//EN">

       createExternalSubset
             $dtd = $document->createExternalSubset( $rootnode_name, $publicId, $systemId);

           This function is similar to "createInternalSubset()" but this DTD is considered to be external
           and is therefore not added to the document itself. Nevertheless it can be used for validation
           purposes.

       importNode
             $document->importNode( $node );

           If a node is not part of a document, it can be imported to another document. As specified in DOM
           Level 2 Specification the Node will not be altered or removed from its original document
           ("$node->cloneNode(1)" will get called implicitly).

           NOTE: Don't try to use importNode() to import sub-trees that contain an entity reference - even
           if the entity reference is the root node of the sub-tree. This will cause serious problems to
           your program. This is a limitation of libxml2 and not of XML::LibXML itself.

       adoptNode
             $document->adoptNode( $node );

           If a node is not part of a document, it can be imported to another document. As specified in DOM
           Level 3 Specification the Node will not be altered but it will removed from its original
           document.

           After a document adopted a node, the node, its attributes and all its descendants belong to the
           new document. Because the node does not belong to the old document, it will be unlinked from its
           old location first.

           NOTE: Don't try to adoptNode() to import sub-trees that contain entity references - even if the
           entity reference is the root node of the sub-tree. This will cause serious problems to your
           program. This is a limitation of libxml2 and not of XML::LibXML itself.

       externalSubset
             my $dtd = $doc->externalSubset;

           If a document has an external subset defined it will be returned by this function.

           NOTE Dtd nodes are no ordinary nodes in libxml2. The support for these nodes in XML::LibXML is
           still limited. In particular one may not want use common node function on doctype declaration
           nodes!

       internalSubset
             my $dtd = $doc->internalSubset;

           If a document has an internal subset defined it will be returned by this function.

           NOTE Dtd nodes are no ordinary nodes in libxml2. The support for these nodes in XML::LibXML is
           still limited. In particular one may not want use common node function on doctype declaration
           nodes!

       setExternalSubset
             $doc->setExternalSubset($dtd);

           EXPERIMENTAL!

           This method sets a DTD node as an external subset of the given document.

       setInternalSubset
             $doc->setInternalSubset($dtd);

           EXPERIMENTAL!

           This method sets a DTD node as an internal subset of the given document.

       removeExternalSubset
             my $dtd = $doc->removeExternalSubset();

           EXPERIMENTAL!

           If a document has an external subset defined it can be removed from the document by using this
           function. The removed dtd node will be returned.

       removeInternalSubset
             my $dtd = $doc->removeInternalSubset();

           EXPERIMENTAL!

           If a document has an internal subset defined it can be removed from the document by using this
           function. The removed dtd node will be returned.

       getElementsByTagName
             my @nodelist = $doc->getElementsByTagName($tagname);

           Implements the DOM Level 2 function

           In SCALAR context this function returns an XML::LibXML::NodeList object.

       getElementsByTagNameNS
             my @nodelist = $doc->getElementsByTagNameNS($nsURI,$tagname);

           Implements the DOM Level 2 function

           In SCALAR context this function returns an XML::LibXML::NodeList object.

       getElementsByLocalName
             my @nodelist = $doc->getElementsByLocalName($localname);

           This allows the fetching of all nodes from a given document with the given Localname.

           In SCALAR context this function returns an XML::LibXML::NodeList object.

       getElementById
             my $node = $doc->getElementById($id);

           Returns the element that has an ID attribute with the given value. If no such element exists,
           this returns undef.

           Note: the ID of an element may change while manipulating the document. For documents with a DTD,
           the information about ID attributes is only available if DTD loading/validation has been
           requested. For HTML documents parsed with the HTML parser ID detection is done automatically. In
           XML documents, all "xml:id" attributes are considered to be of type ID. You can test ID-ness of
           an attribute node with $attr->isId().

           In versions 1.59 and earlier this method was called getElementsById() (plural) by mistake.
           Starting from 1.60 this name is maintained as an alias only for backward compatibility.

       indexElements
             $dom->indexElements();

           This function causes libxml2 to stamp all elements in a document with their document position
           index which considerably speeds up XPath queries for large documents. It should only be used with
           static documents that won't be further changed by any DOM methods, because once a document is
           indexed, XPath will always prefer the index to other methods of determining the document order of
           nodes. XPath could therefore return improperly ordered node-lists when applied on a document that
           has been changed after being indexed. It is of course possible to use this method to re-index a
           modified document before using it with XPath again. This function is not a part of the DOM
           specification.

           This function returns number of elements indexed, -1 if error occurred, or -2 if this feature is
           not available in the running libxml2.

AUTHORS
       Matt Sergeant, Christian Glahn, Petr Pajas

VERSION
       2.0008

COPYRIGHT
       2001-2007, AxKit.com Ltd.

       2002-2006, Christian Glahn.

       2006-2009, Petr Pajas.



perl v5.16.2                                     2012-10-22                         XML::LibXML::Document(3)