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 increases some hardcoded limits 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.

Caution

Because this increases the hardcoded limits, it should only be used with trusted data. Raising the depth limit on untrusted input can lead to excessive resource consumption, such as a stack overflow while processing a deeply nested document.

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)