预定义常量

下列常量由此扩展定义，且仅在此扩展编译入 PHP 或在运行时动态载入时可用。

LIBXML_BIGLINES ( integer ): Allows line numbers greater than 65535 to be reported correctly.

Note:

Only available as of PHP 7.0.0 with Libxml >= 2.9.0
LIBXML_COMPACT ( integer ): Activate small nodes allocation optimization. This may speed up your application without needing to change the code.

Note:

Only available in Libxml >= 2.6.21
LIBXML_DTDATTR ( integer ): Default DTD attributes
LIBXML_DTDLOAD ( integer ): Load the external subset
LIBXML_DTDVALID ( integer ): Validate with the DTD
LIBXML_HTML_NOIMPLIED ( integer ): Sets HTML_PARSE_NOIMPLIED flag, which turns off the automatic adding of implied html/body... elements.

Note:

Only available in Libxml >= 2.7.7 (as of PHP >= 5.4.0)
LIBXML_HTML_NODEFDTD ( integer ): Sets HTML_PARSE_NODEFDTD flag, which prevents a default doctype being added when one is not found.

Note:

Only available in Libxml >= 2.7.8 (as of PHP >= 5.4.0)
LIBXML_NOBLANKS ( integer ): Remove blank nodes
LIBXML_NOCDATA ( integer ): Merge CDATA as text nodes
LIBXML_NOEMPTYTAG ( integer ): Expand empty tags (e.g. <br/> to <br></br>)

Note:

This option is currently just available in the DOMDocument::save and DOMDocument::saveXML functions.
LIBXML_NOENT ( integer ): Substitute entities
LIBXML_NOERROR ( integer ): Suppress error reports
LIBXML_NONET ( integer ): Disable network access when loading documents
LIBXML_NOWARNING ( integer ): Suppress warning reports
LIBXML_NOXMLDECL ( integer ): Drop the XML declaration when saving a document

Note:

Only available in Libxml >= 2.6.21
LIBXML_NSCLEAN ( integer ): Remove redundant namespace declarations
LIBXML_PARSEHUGE ( integer ): Sets XML_PARSE_HUGE flag, which relaxes any hardcoded limit from the parser. This affects limits like maximum depth of a document or the entity recursion, as well as limits of the size of text nodes.

Note:

Only available in Libxml >= 2.7.0 (as of PHP >= 5.3.2 and PHP >= 5.2.12)
LIBXML_PEDANTIC ( integer ): Sets XML_PARSE_PEDANTIC flag, which enables pedantic error reporting.

Note:

Available as of PHP >= 5.4.0
LIBXML_XINCLUDE ( integer ): Implement XInclude substitution
LIBXML_ERR_ERROR ( integer ): A recoverable error
LIBXML_ERR_FATAL ( integer ): A fatal error
LIBXML_ERR_NONE ( integer ): No errors
LIBXML_ERR_WARNING ( integer ): A simple warning
LIBXML_VERSION ( integer ): libxml version like 20605 or 20617
LIBXML_DOTTED_VERSION ( string ): libxml version like 2.6.5 or 2.6.17
LIBXML_SCHEMA_CREATE ( integer ): Create default/fixed value nodes during XSD schema validation

Note:

Only available in Libxml >= 2.6.14 (as of PHP >= 5.5.2)

用户评论:

[#1] RiKdnua at mail dot ru [2015-09-29 15:31:24]

Tested in PHP 5.2.9-2 (libxml Version 2.7.3) and PHP 5.2.17 (libxml Version 2.8.0)
In SimpleXMLElement LIBXML_NOXMLDECL does not work. XML declaration will be written to a file doc.xml
<?php ini_set("display_errors","on"); error_reporting(-1); $xml="<?xml version='1.0'?>
<root><child>text</child></root>";
$xml=new simpleXMLelement($xml, LIBXML_NOXMLDECL);
$xml->asXML('doc.xml');
?>

[#2] @oneseventeen [2011-02-05 23:51:20]

When inserting XML DOM Elements inside existing XML DOM Elements that I loaded from an XML file using the following code, none of my new elements were formatted correctly, they just showed up on one line:

<?php $dom = DOMDocument::load('file.xml'); $dom->formatOutput = true; //$dom->add some new elements with child nodes somewhere inside the loaded XML using insertBefore(); $dom->saveXML(); //output: everything looks normal but the new nodes are all on one line. ?>

I found I could pass LIBXML_NOBLANKS to the load method and it would reformat the whole document, including my added stuff:
<?php $dom = DOMDocument::load('file.xml', LIBXML_NOBLANKS); $dom->formatOutput = true; //$dom->add some new elements with child nodes somewhere inside the loaded XML using insertBefore(); $dom->saveXML(); //output: everything looks newly formatted, including new nodes ?>

Hope this helps, took me hours of trial and error to figure this out!

[#3] zachatwork at gmail dot com [2010-02-09 23:30:58]

Note: The LIBXML_NOXMLDECL constant is defined in this library but is not supported by DOMDocument (yet).

See also: http://bugs.php.net/bug.php?id=47137

<?php print "PHP_VERSION:      ".PHP_VERSION."\n"; print "LIBXML_VERSION:   ".LIBXML_VERSION."\n"; print "LIBXML_NOXMLDECL: ".LIBXML_NOXMLDECL."\n"; $dom = new DomDocument(); $dom->loadXML("<foo />"); # This should work but doesn't. print "DOMDocument doesn't honor LIBXML_NOXMLDECL:\n"; print $dom->saveXML(null,LIBXML_NOXMLDECL); # This works, and will still work after the above is fixed. print "Forwards compatible workaround:\n"; $lines = explode("\n", $dom->saveXML(null, LIBXML_NOXMLDECL), 2); if(!preg_match('/^\<\?xml/', $lines[0]))     print $lines[0]; print $lines[1]; ?>

PHP_VERSION:      5.3.1-0.dotdeb.1
LIBXML_VERSION:   20632
LIBXML_NOXMLDECL: 2
DOMDocument doesn't honor LIBXML_NOXMLDECL:
<?phpxml version="1.0"?>
<foo/>
Forwards compatible workaround:
<foo/>