1XML::LibXML::Document(3U)ser Contributed Perl DocumentatiXoMnL::LibXML::Document(3)
2
6 XML::LibXML::Document - XML::LibXML DOM Document Class
7
9 use XML::LibXML;
10 # Only methods specific to Document nodes are listed here,
11 # see the XML::LibXML::Node manpage for other methods
12 $dom = XML::LibXML::Document->new( $version, $encoding );
14 $dom = XML::LibXML::Document->createDocument( $version, $encoding );
15 $strURI = $doc->URI();
16 $doc->setURI($strURI);
17 $strEncoding = $doc->encoding();
18 $strEncoding = $doc->actualEncoding();
19 $doc->setEncoding($new_encoding);
20 $strVersion = $doc->version();
21 $doc->standalone
22 $doc->setStandalone($numvalue);
23 my $compression = $doc->compression;
24 $doc->setCompression($ziplevel);
25 $docstring = $dom->toString($format);
26 $c14nstr = $doc->toStringC14N($comment_flag, $xpath [, $xpath_context ]);
27 $ec14nstr = $doc->toStringEC14N($comment_flag, $xpath [, $xpath_context ], $inclusive_prefix_list);
28 $str = $doc->serialize($format);
29 $state = $doc->toFile($filename, $format);
30 $state = $doc->toFH($fh, $format);
31 $str = $document->toStringHTML();
32 $str = $document->serialize_html();
33 $bool = $dom->is_valid();
34 $dom->validate();
35 $root = $dom->documentElement();
36 $dom->setDocumentElement( $root );
37 $element = $dom->createElement( $nodename );
38 $element = $dom->createElementNS( $namespaceURI, $nodename );
39 $text = $dom->createTextNode( $content_text );
40 $comment = $dom->createComment( $comment_text );
41 $attrnode = $doc->createAttribute($name [,$value]);
42 $attrnode = $doc->createAttributeNS( namespaceURI, $name [,$value] );
43 $fragment = $doc->createDocumentFragment();
44 $cdata = $dom->createCDATASection( $cdata_content );
45 my $pi = $doc->createProcessingInstruction( $target, $data );
46 my $entref = $doc->createEntityReference($refname);
47 $dtd = $document->createInternalSubset( $rootnode, $public, $system);
48 $dtd = $document->createExternalSubset( $rootnode_name, $publicId, $systemId);
49 $document->importNode( $node );
50 $document->adoptNode( $node );
51 my $dtd = $doc->externalSubset;
52 my $dtd = $doc->internalSubset;
53 $doc->setExternalSubset($dtd);
54 $doc->setInternalSubset($dtd);
55 my $dtd = $doc->removeExternalSubset();
56 my $dtd = $doc->removeInternalSubset();
57 my @nodelist = $doc->getElementsByTagName($tagname);
58 my @nodelist = $doc->getElementsByTagNameNS($nsURI,$tagname);
59 my @nodelist = $doc->getElementsByLocalName($localname);
60 my $node = $doc->getElementById($id);
61 $dom->indexElements();
62
64 The Document Class is in most cases the result of a parsing process.
65 But sometimes it is necessary to create a Document from scratch. The
66 DOM Document Class provides functions that conform to the DOM Core
67 naming style.
68 It inherits all functions from XML::LibXML::Node as specified in the
70 DOM specification. This enables access to the nodes besides the root
71 element on document level - a "DTD" for example. The support for these
72 nodes is limited at the moment.
73 While generally nodes are bound to a document in the DOM concept it is
75 suggested that one should always create a node not bound to any
76 document. There is no need of really including the node to the
77 document, but once the node is bound to a document, it is quite safe
78 that all strings have the correct encoding. If an unbound text node
79 with an ISO encoded string is created (e.g. with $CLASS->new()), the
80 "toString" function may not return the expected result.
81 To prevent such problems, it is recommended to pass all data to
83 XML::LibXML methods as character strings (i.e. UTF-8 encoded, with the
84 UTF8 flag on).
85
87 Many functions listed here are extensively documented in the DOM Level
88 3 specification (<http://www.w3.org/TR/DOM-Level-3-Core/>). Please
89 refer to the specification for extensive documentation.
90 new
92 $dom = XML::LibXML::Document->new( $version, $encoding );
93 alias for createDocument()
95 createDocument
97 $dom = XML::LibXML::Document->createDocument( $version, $encoding );
98 The constructor for the document class. As Parameter it takes the
100 version string and (optionally) the encoding string. Simply calling
101 createDocument() will create the document:
102 <?xml version="your version" encoding="your encoding"?>
104 Both parameter are optional. The default value for $version is 1.0,
106 of course. If the $encoding parameter is not set, the encoding will
107 be left unset, which means UTF-8 is implied.
108 The call of createDocument() without any parameter will result the
110 following code:
111 <?xml version="1.0"?>
113 Alternatively one can call this constructor directly from the
115 XML::LibXML class level, to avoid some typing. This will not have
116 any effect on the class instance, which is always
117 XML::LibXML::Document.
118 my $document = XML::LibXML->createDocument( "1.0", "UTF-8" );
120 is therefore a shortcut for
122 my $document = XML::LibXML::Document->createDocument( "1.0", "UTF-8" );
124 URI
126 $strURI = $doc->URI();
127 Returns the URI (or filename) of the original document. For
129 documents obtained by parsing a string of a FH without using the
130 URI parsing argument of the corresponding "parse_*" function, the
131 result is a generated string unknown-XYZ where XYZ is some number;
132 for documents created with the constructor "new", the URI is
133 undefined.
134 The value can be modified by calling "setURI" method on the
136 document node.
137 setURI
139 $doc->setURI($strURI);
140 Sets the URI of the document reported by the method URI (see also
142 the URI argument to the various "parse_*" functions).
143 encoding
145 $strEncoding = $doc->encoding();
146 returns the encoding string of the document.
148 my $doc = XML::LibXML->createDocument( "1.0", "ISO-8859-15" );
150 print $doc->encoding; # prints ISO-8859-15
151 actualEncoding
153 $strEncoding = $doc->actualEncoding();
154 returns the encoding in which the XML will be returned by
156 $doc->toString(). This is usually the original encoding of the
157 document as declared in the XML declaration and returned by
158 $doc->encoding. If the original encoding is not known (e.g. if
159 created in memory or parsed from a XML without a declared
160 encoding), 'UTF-8' is returned.
161 my $doc = XML::LibXML->createDocument( "1.0", "ISO-8859-15" );
163 print $doc->encoding; # prints ISO-8859-15
164 setEncoding
166 $doc->setEncoding($new_encoding);
167 This method allows one to change the declaration of encoding in the
169 XML declaration of the document. The value also affects the
170 encoding in which the document is serialized to XML by
171 $doc->toString(). Use setEncoding() to remove the encoding
172 declaration.
173 version
175 $strVersion = $doc->version();
176 returns the version string of the document
178 getVersion() is an alternative form of this function.
180 standalone
182 $doc->standalone
183 This function returns the Numerical value of a documents XML
185 declarations standalone attribute. It returns 1 if standalone="yes"
186 was found, 0 if standalone="no" was found and -1 if standalone was
187 not specified (default on creation).
188 setStandalone
190 $doc->setStandalone($numvalue);
191 Through this method it is possible to alter the value of a
193 documents standalone attribute. Set it to 1 to set
194 standalone="yes", to 0 to set standalone="no" or set it to -1 to
195 remove the standalone attribute from the XML declaration.
196 compression
198 my $compression = $doc->compression;
199 libxml2 allows reading of documents directly from gzipped files. In
201 this case the compression variable is set to the compression level
202 of that file (0-8). If XML::LibXML parsed a different source or the
203 file wasn't compressed, the returned value will be -1.
204 setCompression
206 $doc->setCompression($ziplevel);
207 If one intends to write the document directly to a file, it is
209 possible to set the compression level for a given document. This
210 level can be in the range from 0 to 8. If XML::LibXML should not
211 try to compress use -1 (default).
212 Note that this feature will only work if libxml2 is compiled with
214 zlib support and toFile() is used for output.
215 toString
217 $docstring = $dom->toString($format);
218 toString is a DOM serializing function, so the DOM Tree is
220 serialized into an XML string, ready for output.
221 IMPORTANT: unlike toString for other nodes, on document nodes this
223 function returns the XML as a byte string in the original encoding
224 of the document (see the actualEncoding() method)! This means you
225 can simply do:
226 open my $out_fh, '>', $file;
228 print {$out_fh} $doc->toString;
229 regardless of the actual encoding of the document. See the section
231 on encodings in XML::LibXML for more details.
232 The optional $format parameter sets the indenting of the output.
234 This parameter is expected to be an "integer" value, that specifies
235 that indentation should be used. The format parameter can have
236 three different values if it is used:
237 If $format is 0, than the document is dumped as it was originally
239 parsed
240 If $format is 1, libxml2 will add ignorable white spaces, so the
242 nodes content is easier to read. Existing text nodes will not be
243 altered
244 If $format is 2 (or higher), libxml2 will act as $format == 1 but
246 it add a leading and a trailing line break to each text node.
247 libxml2 uses a hard-coded indentation of 2 space characters per
249 indentation level. This value can not be altered on run-time.
250 toStringC14N
252 $c14nstr = $doc->toStringC14N($comment_flag, $xpath [, $xpath_context ]);
253 See the documentation in XML::LibXML::Node.
255 toStringEC14N
257 $ec14nstr = $doc->toStringEC14N($comment_flag, $xpath [, $xpath_context ], $inclusive_prefix_list);
258 See the documentation in XML::LibXML::Node.
260 serialize
262 $str = $doc->serialize($format);
263 An alias for toString(). This function was name added to be more
265 consistent with libxml2.
266 serialize_c14n
268 An alias for toStringC14N().
269 serialize_exc_c14n
271 An alias for toStringEC14N().
272 toFile
274 $state = $doc->toFile($filename, $format);
275 This function is similar to toString(), but it writes the document
277 directly into a filesystem. This function is very useful, if one
278 needs to store large documents.
279 The format parameter has the same behaviour as in toString().
281 toFH
283 $state = $doc->toFH($fh, $format);
284 This function is similar to toString(), but it writes the document
286 directly to a filehandle or a stream. A byte stream in the document
287 encoding is passed to the file handle. Do NOT apply any
288 ":encoding(...)" or ":utf8" PerlIO layer to the filehandle! See the
289 section on encodings in XML::LibXML for more details.
290 The format parameter has the same behaviour as in toString().
292 toStringHTML
294 $str = $document->toStringHTML();
295 toStringHTML serialize the tree to a byte string in the document
297 encoding as HTML. With this method indenting is automatic and
298 managed by libxml2 internally.
299 serialize_html
301 $str = $document->serialize_html();
302 An alias for toStringHTML().
304 is_valid
306 $bool = $dom->is_valid();
307 Returns either TRUE or FALSE depending on whether the DOM Tree is a
309 valid Document or not.
310 You may also pass in a XML::LibXML::Dtd object, to validate against
312 an external DTD:
313 if (!$dom->is_valid($dtd)) {
315 warn("document is not valid!");
316 }
317 validate
319 $dom->validate();
320 This is an exception throwing equivalent of is_valid. If the
322 document is not valid it will throw an exception containing the
323 error. This allows you much better error reporting than simply
324 is_valid or not.
325 Again, you may pass in a DTD object
327 documentElement
329 $root = $dom->documentElement();
330 Returns the root element of the Document. A document can have just
332 one root element to contain the documents data.
333 Optionally one can use getDocumentElement.
335 setDocumentElement
337 $dom->setDocumentElement( $root );
338 This function enables you to set the root element for a document.
340 The function supports the import of a node from a different
341 document tree, but does not support a document fragment as $root.
342 createElement
344 $element = $dom->createElement( $nodename );
345 This function creates a new Element Node bound to the DOM with the
347 name $nodename.
348 createElementNS
350 $element = $dom->createElementNS( $namespaceURI, $nodename );
351 This function creates a new Element Node bound to the DOM with the
353 name $nodename and placed in the given namespace.
354 createTextNode
356 $text = $dom->createTextNode( $content_text );
357 As an equivalent of createElement, but it creates a Text Node bound
359 to the DOM.
360 createComment
362 $comment = $dom->createComment( $comment_text );
363 As an equivalent of createElement, but it creates a Comment Node
365 bound to the DOM.
366 createAttribute
368 $attrnode = $doc->createAttribute($name [,$value]);
369 Creates a new Attribute node.
371 createAttributeNS
373 $attrnode = $doc->createAttributeNS( namespaceURI, $name [,$value] );
374 Creates an Attribute bound to a namespace.
376 createDocumentFragment
378 $fragment = $doc->createDocumentFragment();
379 This function creates a DocumentFragment.
381 createCDATASection
383 $cdata = $dom->createCDATASection( $cdata_content );
384 Similar to createTextNode and createComment, this function creates
386 a CDataSection bound to the current DOM.
387 createProcessingInstruction
389 my $pi = $doc->createProcessingInstruction( $target, $data );
390 create a processing instruction node.
392 Since this method is quite long one may use its short form
394 createPI().
395 createEntityReference
397 my $entref = $doc->createEntityReference($refname);
398 If a document has a DTD specified, one can create entity references
400 by using this function. If one wants to add a entity reference to
401 the document, this reference has to be created by this function.
402 An entity reference is unique to a document and cannot be passed to
404 other documents as other nodes can be passed.
405 NOTE: A text content containing something that looks like an entity
407 reference, will not be expanded to a real entity reference unless
408 it is a predefined entity
409 my $string = "&foo;";
411 $some_element->appendText( $string );
412 print $some_element->textContent; # prints "&foo;"
413 createInternalSubset
415 $dtd = $document->createInternalSubset( $rootnode, $public, $system);
416 This function creates and adds an internal subset to the given
418 document. Because the function automatically adds the DTD to the
419 document there is no need to add the created node explicitly to the
420 document.
421 my $document = XML::LibXML::Document->new();
423 my $dtd = $document->createInternalSubset( "foo", undef, "foo.dtd" );
424 will result in the following XML document:
426 <?xml version="1.0"?>
428 <!DOCTYPE foo SYSTEM "foo.dtd">
429 By setting the public parameter it is possible to set PUBLIC DTDs
431 to a given document. So
432 my $document = XML::LibXML::Document->new();
434 my $dtd = $document->createInternalSubset( "foo", "-//FOO//DTD FOO 0.1//EN", undef );
435 will cause the following declaration to be created on the document:
437 <?xml version="1.0"?>
439 <!DOCTYPE foo PUBLIC "-//FOO//DTD FOO 0.1//EN">
440 createExternalSubset
442 $dtd = $document->createExternalSubset( $rootnode_name, $publicId, $systemId);
443 This function is similar to "createInternalSubset()" but this DTD
445 is considered to be external and is therefore not added to the
446 document itself. Nevertheless it can be used for validation
447 purposes.
448 importNode
450 $document->importNode( $node );
451 If a node is not part of a document, it can be imported to another
453 document. As specified in DOM Level 2 Specification the Node will
454 not be altered or removed from its original document
455 ("$node->cloneNode(1)" will get called implicitly).
456 NOTE: Don't try to use importNode() to import sub-trees that
458 contain an entity reference - even if the entity reference is the
459 root node of the sub-tree. This will cause serious problems to your
460 program. This is a limitation of libxml2 and not of XML::LibXML
461 itself.
462 adoptNode
464 $document->adoptNode( $node );
465 If a node is not part of a document, it can be imported to another
467 document. As specified in DOM Level 3 Specification the Node will
468 not be altered but it will removed from its original document.
469 After a document adopted a node, the node, its attributes and all
471 its descendants belong to the new document. Because the node does
472 not belong to the old document, it will be unlinked from its old
473 location first.
474 NOTE: Don't try to adoptNode() to import sub-trees that contain
476 entity references - even if the entity reference is the root node
477 of the sub-tree. This will cause serious problems to your program.
478 This is a limitation of libxml2 and not of XML::LibXML itself.
479 externalSubset
481 my $dtd = $doc->externalSubset;
482 If a document has an external subset defined it will be returned by
484 this function.
485 NOTE Dtd nodes are no ordinary nodes in libxml2. The support for
487 these nodes in XML::LibXML is still limited. In particular one may
488 not want use common node function on doctype declaration nodes!
489 internalSubset
491 my $dtd = $doc->internalSubset;
492 If a document has an internal subset defined it will be returned by
494 this function.
495 NOTE Dtd nodes are no ordinary nodes in libxml2. The support for
497 these nodes in XML::LibXML is still limited. In particular one may
498 not want use common node function on doctype declaration nodes!
499 setExternalSubset
501 $doc->setExternalSubset($dtd);
502 EXPERIMENTAL!
504 This method sets a DTD node as an external subset of the given
506 document.
507 setInternalSubset
509 $doc->setInternalSubset($dtd);
510 EXPERIMENTAL!
512 This method sets a DTD node as an internal subset of the given
514 document.
515 removeExternalSubset
517 my $dtd = $doc->removeExternalSubset();
518 EXPERIMENTAL!
520 If a document has an external subset defined it can be removed from
522 the document by using this function. The removed dtd node will be
523 returned.
524 removeInternalSubset
526 my $dtd = $doc->removeInternalSubset();
527 EXPERIMENTAL!
529 If a document has an internal subset defined it can be removed from
531 the document by using this function. The removed dtd node will be
532 returned.
533 getElementsByTagName
535 my @nodelist = $doc->getElementsByTagName($tagname);
536 Implements the DOM Level 2 function
538 In SCALAR context this function returns an XML::LibXML::NodeList
540 object.
541 getElementsByTagNameNS
543 my @nodelist = $doc->getElementsByTagNameNS($nsURI,$tagname);
544 Implements the DOM Level 2 function
546 In SCALAR context this function returns an XML::LibXML::NodeList
548 object.
549 getElementsByLocalName
551 my @nodelist = $doc->getElementsByLocalName($localname);
552 This allows the fetching of all nodes from a given document with
554 the given Localname.
555 In SCALAR context this function returns an XML::LibXML::NodeList
557 object.
558 getElementById
560 my $node = $doc->getElementById($id);
561 Returns the element that has an ID attribute with the given value.
563 If no such element exists, this returns undef.
564 Note: the ID of an element may change while manipulating the
566 document. For documents with a DTD, the information about ID
567 attributes is only available if DTD loading/validation has been
568 requested. For HTML documents parsed with the HTML parser ID
569 detection is done automatically. In XML documents, all "xml:id"
570 attributes are considered to be of type ID. You can test ID-ness of
571 an attribute node with $attr->isId().
572 In versions 1.59 and earlier this method was called
574 getElementsById() (plural) by mistake. Starting from 1.60 this name
575 is maintained as an alias only for backward compatibility.
576 indexElements
578 $dom->indexElements();
579 This function causes libxml2 to stamp all elements in a document
581 with their document position index which considerably speeds up
582 XPath queries for large documents. It should only be used with
583 static documents that won't be further changed by any DOM methods,
584 because once a document is indexed, XPath will always prefer the
585 index to other methods of determining the document order of nodes.
586 XPath could therefore return improperly ordered node-lists when
587 applied on a document that has been changed after being indexed. It
588 is of course possible to use this method to re-index a modified
589 document before using it with XPath again. This function is not a
590 part of the DOM specification.
591 This function returns number of elements indexed, -1 if error
593 occurred, or -2 if this feature is not available in the running
594 libxml2.
595
597 Matt Sergeant, Christian Glahn, Petr Pajas
598
600 2.0207
601
603 2001-2007, AxKit.com Ltd.
604 2002-2006, Christian Glahn.
606 2006-2009, Petr Pajas.
608
610 This program is free software; you can redistribute it and/or modify it
611 under the same terms as Perl itself.
612perl v5.34.0 2022-01-21 XML::LibXML::Document(3)