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

Caution

Enabling loading of DTD attributes will enable fetching of external entities. The LIBXML_NO_XXE constant can be used to prevent this (only available in Libxml >= 2.13.0, as of PHP 8.4.0).

LIBXML_DTDLOAD (int)

Load the external subset

Caution

Enabling loading of external subsets will enable fetching of external entities. The LIBXML_NO_XXE constant can be used to prevent this (only available in Libxml >= 2.13.0, as of PHP 8.4.0).

LIBXML_DTDVALID (int)

Validate with the DTD

Caution

Enabling validating the DTD may facilitate XML External Entity (XXE) attacks. The LIBXML_NO_XXE constant can be used to prevent this (only available in Libxml >= 2.13.0, as of PHP 8.4.0).

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)

Perform XInclude substitution (only for pull parsers, i.e. XMLReader).

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)