libxml
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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_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_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 namespaces 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_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
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PHP手册 - N: 预定义常量

用户评论:

@oneseventeen (06-Feb-2011 07:51)

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!

zachatwork at gmail dot com (10-Feb-2010 07:30)

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:
<?xml version="1.0"?>
<foo/>
Forwards compatible workaround:
<foo/>