DOM XML Functions


The DOM XML extension has been overhauled in PHP 4.3.0 to better comply with the DOM standard. The extension still contains many old functions, but they should no longer be used. In particular, functions that are not object-oriented should be avoided.

The extension allows you to operate on an XML document with the DOM API. It also provides a function domxml_xmltree() to turn the complete XML document into a tree of PHP objects. Currently, this tree should be considered read-only - you can modify it, but this would not make any sense since DomDocument_dump_mem() cannot be applied to it. Therefore, if you want to read an XML file and write a modified version, use DomDocument_create_element(), DomDocument_create_text_node(), set_attribute(), etc. and finally the DomDocument_dump_mem() function.

Note: 本扩展已被移动到 » PECL 库中且自以下版本起不再被绑定到 PHP 中:5.0.0.

Note: This extension is no longer marked experimental. It will, however, never be released with PHP 5, and will only be distributed with PHP 4. If you need DOM XML support with PHP 5 you can use the DOM extension. This domxml extension is not compatible with the DOM extension.


This extension makes use of the » GNOME XML library. Download and install this library. You will need at least libxml-2.4.14. To use DOM XSLT features you can use the » libxslt library and EXSLT enhancements from » Download and install these libraries if you plan to use (enhanced) XSLT features. You will need at least libxslt-1.0.18.


» PECL 扩展未绑定于 PHP 中。 安装此 PECL 扩展库的信息可在手册中标题为 PECL 扩展库安装的一章中找到。 更多信息如新版本,下载,源文件,维护者信息以及更新日志等可以在这里找到: »

在 PHP 4 中本 PECL 扩展的源程序位于 PHP 源程序中的 ext/ 目录下或者在上面的 PECL 连接中。 This extension is only available if PHP was configured with --with-dom[=DIR]. Add --with-dom-xslt[=DIR] to include DOM XSLT support. DIR is the libxslt install directory. Add --with-dom-exslt[=DIR] to include DOM EXSLT support, where DIR is the libexslt install directory.

Windows users will enable php_domxml.dll inside of php.ini in order to use these functions. 在 PHP 4 中本 DLL 位于 PHP Windows 执行包中的 extensions/ 目录下。 可以从 » PHP 下载页面或者 » 下载此 PECL 扩展的 DLL 文件。 Also, there is one additional DLL that must be made available to your system's PATH in order for this extension to work. In PHP 4 this is in the dlls/ directory. It's name: For PHP <= 4.2.0, it's libxml2.dll. For PHP >= 4.3.0, it's iconv.dll. And as of PHP 5.0.0, iconv is compiled into your Windows PHP binaries by default so no extra DLL is needed.

Deprecated functions

There are quite a few functions that do not fit into the DOM standard and should no longer be used. These functions are listed in the following table. The function DomNode_append_child() has changed its behaviour. It now adds a child and not a sibling. If this breaks your application, use the non-DOM function DomNode_append_sibling().

Deprecated functions and their replacements
Old function New function
xmldoc domxml_open_mem()
xmldocfile domxml_open_file()
domxml_new_xmldoc domxml_new_doc()
domxml_dump_mem DomDocument_dump_mem()
domxml_dump_mem_file DomDocument_dump_file()
DomDocument_dump_mem_file DomDocument_dump_file()
DomDocument_add_root DomDocument_create_element() followed by DomNode_append_child()
DomDocument_dtd DomDocument_doctype()
DomDocument_root DomDocument_document_element()
DomDocument_children DomNode_child_nodes()
DomDocument_imported_node No replacement.
DomNode_add_child Create a new node with e.g. DomDocument_create_element() and add it with DomNode_append_child().
DomNode_children DomNode_child_nodes()
DomNode_parent DomNode_parent_node()
DomNode_new_child Create a new node with e.g. DomDocument_create_element() and add it with DomNode_append_child().
DomNode_set_content Create a new node with e.g. DomDocument_create_text_node() and add it with DomNode_append_child().
DomNode_get_content Content is just a text node and can be accessed with DomNode_child_nodes().
DomNode_set_content Content is just a text node and can be added with DomNode_append_child().


以下常量由本扩展模块定义,因此只有在本扩展模块被编译到 PHP 中,或者在运行时被动态加载后才有效。

XML constants
Constant Value Description
XML_ELEMENT_NODE (integer) 1 Node is an element
XML_ATTRIBUTE_NODE (integer) 2 Node is an attribute
XML_TEXT_NODE (integer) 3 Node is a piece of text
XML_ENTITY_REF_NODE (integer) 5  
XML_ENTITY_NODE (integer) 6 Node is an entity like &nbsp;
XML_PI_NODE (integer) 7 Node is a processing instruction
XML_COMMENT_NODE (integer) 8 Node is a comment
XML_DOCUMENT_NODE (integer) 9 Node is a document
XML_NOTATION_NODE (integer) 12  
XML_DTD_NODE (integer)    
XML_ENTITY_DECL_NODE (integer)    
XML_ATTRIBUTE_ID (integer)    
XPATH_UNDEFINED (integer)    
XPATH_NODESET (integer)    
XPATH_BOOLEAN (integer)    
XPATH_NUMBER (integer)    
XPATH_STRING (integer)    
XPATH_POINT (integer)    
XPATH_RANGE (integer)    
XPATH_USERS (integer)    
XPATH_NUMBER (integer)    


The API of the module follows the DOM Level 2 standard as closely as possible. Consequently, the API is fully object-oriented. It is a good idea to have the DOM standard available when using this module. Though the API is object-oriented, there are many functions which can be called in a non-object-oriented way by passing the object to operate on as the first argument. These functions are mainly to retain compatibility to older versions of the extension, and should not be used when creating new scripts.

This API differs from the official DOM API in two ways. First, all class attributes are implemented as functions with the same name. Secondly, the function names follow the PHP naming convention. This means that a DOM function lastChild() will be written as last_child().

This module defines a number of classes, which are listed - including their method - in the following tables. Classes with an equivalent in the DOM standard are named DOMxxx.

List of classes
Class name Parent classes
DomAttribute DomNode
DomCData DomNode
DomComment DomCData : DomNode
DomDocument DomNode
DomDocumentType DomNode
DomElement DomNode
DomEntity DomNode
DomEntityReference DomNode
DomProcessingInstruction DomNode
DomText DomCData : DomNode
Parser Currently still called DomParser

DomDocument class (DomDocument : DomNode)
Method name Function name Remark
doctype DomDocument_doctype()  
document_element DomDocument_document_element()  
create_element DomDocument_create_element()  
create_text_node DomDocument_create_text_node()  
create_comment DomDocument_create_comment()  
create_cdata_section DomDocument_create_cdata_section()  
create_processing_instruction DomDocument_create_processing_instruction()  
create_attribute DomDocument_create_attribute()  
create_entity_reference DomDocument_create_entity_reference()  
get_elements_by_tagname DomDocument_get_elements_by_tagname()  
get_element_by_id DomDocument_get_element_by_id()  
dump_mem DomDocument_dump_mem() not DOM standard
dump_file DomDocument_dump_file() not DOM standard
html_dump_mem DomDocument_html_dump_mem() not DOM standard
xpath_init xpath_init not DOM standard
xpath_new_context xpath_new_context not DOM standard
xptr_new_context xptr_new_context not DOM standard

DomElement class (DomElement : DomNode)
Method name Function name Remark
tagname DomElement_tagname()  
get_attribute DomElement_get_attribute()  
set_attribute DomElement_set_attribute()  
remove_attribute DomElement_remove_attribute()  
get_attribute_node DomElement_get_attribute_node()  
set_attribute_node DomElement_set_attribute_node()  
get_elements_by_tagname DomElement_get_elements_by_tagname()  
has_attribute DomElement_has_attribute()  

DomNode class
Method name Remark
DomNode_append_sibling() Not in DOM standard. This function emulates the former behaviour of DomNode_append_child().
DomNode_unlink_node() Not in DOM standard
DomNode_replace_node() Not in DOM standard
DomNode_set_content() Not in DOM standard, deprecated
DomNode_get_content() Not in DOM standard, deprecated
DomNode_dump_node() Not in DOM standard
DomNode_is_blank_node() Not in DOM standard

DomAttribute class (DomAttribute : DomNode)
Method name Remark
name DomAttribute_name()  
value DomAttribute_value()  
specified DomAttribute_specified()  

DomProcessingInstruction class (DomProcessingInstruction : DomNode)
Method name Function name Remark
target DomProcessingInstruction_target()  
data DomProcessingInstruction_data()  

Parser class
Method name Function name Remark
add_chunk Parser_add_chunk()  
end Parser_end()  

XPathContext class
Method name Function name Remark
eval XPathContext_eval()  
eval_expression XPathContext_eval_expression()  
register_ns XPathContext_register_ns()  

DomDocumentType class (DomDocumentType : DomNode)
Method name Function name Remark
name DomDocumentType_name()  
entities DomDocumentType_entities()  
notations DomDocumentType_notations()  
public_id DomDocumentType_public_id()  
system_id DomDocumentType_system_id()  
internal_subset DomDocumentType_internal_subset()  

The classes DomDtd is derived from DomNode. DomComment is derived from DomCData.


Many examples in this reference require an XML string. Instead of repeating this string in every example, it will be put into a file which will be included by each example. This include file is shown in the following example section. Alternatively, you could create an XML document and read it with DomDocument_open_file().

Example#1 Include file with XML string

"<?xml version='1.0' standalone='yes'?>
<!DOCTYPE chapter SYSTEM '/share/sgml/Norman_Walsh/db3xml10/db3xml10.dtd'
[ <!ENTITY sp \"spanish\">
<!-- lsfj  -->
<chapter language='en'><title language='en'>Title</title>
 <para language='ge'>
  <!-- comment -->
  <informaltable ID='findme' language='&sp;'>
   <tgroup cols='3'>

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