Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

LIBXML_BIGLINES (int)
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 (int)
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 (int)
Default DTD attributes
LIBXML_DTDLOAD (int)
Load the external subset
LIBXML_DTDVALID (int)
Validate with the DTD
Caution

Enabling validating the DTD may facilitate XML External Entity (XXE) attacks.

LIBXML_HTML_NOIMPLIED (int)
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 (int)
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_LOADED_VERSION (string)
Version of libxml's core parser module.
LIBXML_NOBLANKS (int)
Remove blank nodes
LIBXML_NOCDATA (int)
Merge CDATA as text nodes
LIBXML_NOEMPTYTAG (int)
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 (int)
Substitute entities
Caution

Enabling entity substitution may facilitate XML External Entity (XXE) attacks.

LIBXML_NOERROR (int)
Suppress error reports
LIBXML_NONET (int)
Disable network access when loading documents
LIBXML_NOWARNING (int)
Suppress warning reports
LIBXML_NOXMLDECL (int)
Drop the XML declaration when saving a document

Note:

Only available in Libxml >= 2.6.21

LIBXML_NO_XXE (int)
Disables XML External Entities (XXE) when performing entity substitution

Note:

Only available in Libxml >= 2.13.0, as of PHP 8.4.0

LIBXML_NSCLEAN (int)
Remove redundant namespace declarations
LIBXML_PARSEHUGE (int)
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 (int)
Sets XML_PARSE_PEDANTIC flag, which enables pedantic error reporting.

Note:

Available as of PHP >= 5.4.0

LIBXML_RECOVER (int)
Enables recovery mode when parsing a document.

Note:

Only available as of PHP 8.4.0

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

Note:

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