XXXI. DOM XML Functions

Introduction

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: This extension has been moved to the PECL repository and is no longer bundled with PHP as of PHP 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.

Requirements

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 http://www.exslt.org/. Download and install these libraries if you plan to use (enhanced) XSLT features. You will need at least libxslt-1.0.18.

Installation

This PECL extension is not bundled with PHP. Information for installing this PECL extension may be found in the manual chapter titled Installation of PECL extensions. Additional information such as new releases, downloads, source files, maintainer information, and a CHANGELOG, can be located here: http://pecl.php.net/package/domxml.

In PHP 4 this PECL extensions source can be found in the ext/ directory within the PHP source or at the PECL link above. 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. In PHP 4 this DLL resides in the extensions/ directory within the PHP Windows binaries download. The DLL for this PECL extension may be downloaded from either the PHP Downloads page or from http://pecl4win.php.net/ 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().

Table 1. 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().

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.

Table 2. 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_CDATA_SECTION_NODE` (integer)	4
`XML_ENTITY_REF_NODE` (integer)	5
`XML_ENTITY_NODE` (integer)	6	Node is an entity like
`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_DOCUMENT_TYPE_NODE` (integer)	10
`XML_DOCUMENT_FRAG_NODE` (integer)	11
`XML_NOTATION_NODE` (integer)	12
`XML_GLOBAL_NAMESPACE` (integer)	1
`XML_LOCAL_NAMESPACE` (integer)	2
`XML_HTML_DOCUMENT_NODE` (integer)
`XML_DTD_NODE` (integer)
`XML_ELEMENT_DECL_NODE` (integer)
`XML_ATTRIBUTE_DECL_NODE` (integer)
`XML_ENTITY_DECL_NODE` (integer)
`XML_NAMESPACE_DECL_NODE` (integer)
`XML_ATTRIBUTE_CDATA` (integer)
`XML_ATTRIBUTE_ID` (integer)
`XML_ATTRIBUTE_IDREF` (integer)
`XML_ATTRIBUTE_IDREFS` (integer)
`XML_ATTRIBUTE_ENTITY` (integer)
`XML_ATTRIBUTE_NMTOKEN` (integer)
`XML_ATTRIBUTE_NMTOKENS` (integer)
`XML_ATTRIBUTE_ENUMERATION` (integer)
`XML_ATTRIBUTE_NOTATION` (integer)
`XPATH_UNDEFINED` (integer)
`XPATH_NODESET` (integer)
`XPATH_BOOLEAN` (integer)
`XPATH_NUMBER` (integer)
`XPATH_STRING` (integer)
`XPATH_POINT` (integer)
`XPATH_RANGE` (integer)
`XPATH_LOCATIONSET` (integer)
`XPATH_USERS` (integer)
`XPATH_NUMBER` (integer)

Classes

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.

Table 3. 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
XPathContext

Table 4. 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

Table 5. 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()

Table 6. DomNode class

Method name	Remark
DomNode_node_name()
DomNode_node_value()
DomNode_node_type()
DomNode_last_child()
DomNode_first_child()
DomNode_child_nodes()
DomNode_previous_sibling()
DomNode_next_sibling()
DomNode_parent_node()
DomNode_owner_document()
DomNode_insert_before()
DomNode_append_child()
DomNode_append_sibling()	Not in DOM standard. This function emulates the former behaviour of DomNode_append_child().
DomNode_remove_child()
DomNode_has_child_nodes()
DomNode_has_attributes()
DomNode_clone_node()
DomNode_attributes()
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

Table 7. DomAttribute class (DomAttribute : DomNode)

Method name		Remark
name	DomAttribute_name()
value	DomAttribute_value()
specified	DomAttribute_specified()

Table 8. DomProcessingInstruction class (DomProcessingInstruction : DomNode)

Method name	Function name	Remark
target	DomProcessingInstruction_target()
data	DomProcessingInstruction_data()

Table 9. Parser class

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

Table 10. XPathContext class

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

Table 11. 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.

Examples

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 example.inc with XML string


<?php
$xmlstr = "<?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'>
  &sp;
  <!-- comment -->
  <informaltable ID='findme' language='&sp;'>
   <tgroup cols='3'>
    <tbody>
     <row><entry>a1</entry><entry
morerows='1'>b1</entry><entry>c1</entry></row>
<row><entry>a2</entry><entry>c2</entry></row>
     <row><entry>a3</entry><entry>b3</entry><entry>c3</entry></row>
    </tbody>
   </tgroup>
  </informaltable>
 </para>
</chapter>";
?>

Table of Contents
DomAttribute->name -- Returns the name of attribute
DomAttribute->set_value -- Sets the value of an attribute
DomAttribute->specified -- Checks if attribute is specified
DomAttribute->value -- Returns value of attribute
DomDocument->add_root -- Adds a root node [deprecated]
DomDocument->create_attribute -- Create new attribute
DomDocument->create_cdata_section -- Create new cdata node
DomDocument->create_comment -- Create new comment node
DomDocument->create_element_ns -- Create new element node with an associated namespace
DomDocument->create_element -- Create new element node
DomDocument->create_entity_reference -- Create an entity reference
DomDocument->create_processing_instruction -- Creates new PI node
DomDocument->create_text_node -- Create new text node
DomDocument->doctype -- Returns the document type
DomDocument->document_element -- Returns root element node
DomDocument->dump_file -- Dumps the internal XML tree back into a file
DomDocument->dump_mem -- Dumps the internal XML tree back into a string
DomDocument->get_element_by_id -- Searches for an element with a certain id
DomDocument->get_elements_by_tagname -- Returns array with nodes with given tagname in document or empty array, if not found
DomDocument->html_dump_mem -- Dumps the internal XML tree back into a string as HTML
DomDocument->xinclude -- Substitutes XIncludes in a DomDocument Object
DomDocumentType->entities() -- Returns list of entities
DomDocumentType->internal_subset() -- Returns internal subset
DomDocumentType->name() -- Returns name of document type
DomDocumentType->notations() -- Returns list of notations
DomDocumentType->public_id() -- Returns public id of document type
DomDocumentType->system_id() -- Returns the system id of document type
DomElement->get_attribute_node() -- Returns the node of the given attribute
DomElement->get_attribute() -- Returns the value of the given attribute
DomElement->get_elements_by_tagname() -- Gets elements by tagname
DomElement->has_attribute() -- Checks to see if an attribute exists in the current node
DomElement->remove_attribute() -- Removes attribute
DomElement->set_attribute_node() -- Adds new attribute
DomElement->set_attribute() -- Sets the value of an attribute
DomElement->tagname() -- Returns the name of the current element
DomNode->add_namespace -- Adds a namespace declaration to a node
DomNode->append_child -- Adds a new child at the end of the children
DomNode->append_sibling -- Adds new sibling to a node
DomNode->attributes -- Returns list of attributes
DomNode->child_nodes -- Returns children of node
DomNode->clone_node -- Clones a node
DomNode->dump_node -- Dumps a single node
DomNode->first_child -- Returns first child of node
DomNode->get_content -- Gets content of node
DomNode->has_attributes -- Checks if node has attributes
DomNode->has_child_nodes -- Checks if node has children
DomNode->insert_before -- Inserts new node as child
DomNode->is_blank_node -- Checks if node is blank
DomNode->last_child -- Returns last child of node
DomNode->next_sibling -- Returns the next sibling of node
DomNode->node_name -- Returns name of node
DomNode->node_type -- Returns type of node
DomNode->node_value -- Returns value of a node
DomNode->owner_document -- Returns the document this node belongs to
DomNode->parent_node -- Returns the parent of the node
DomNode->prefix -- Returns name space prefix of node
DomNode->previous_sibling -- Returns the previous sibling of node
DomNode->remove_child -- Removes child from list of children
DomNode->replace_child -- Replaces a child
DomNode->replace_node -- Replaces node
DomNode->set_content -- Sets content of node
DomNode->set_name -- Sets name of node
DomNode->set_namespace -- Sets namespace of a node
DomNode->unlink_node -- Deletes node
DomProcessingInstruction->data -- Returns the data of ProcessingInstruction node
DomProcessingInstruction->target -- Returns the target of a ProcessingInstruction node
DomXsltStylesheet->process() -- Applies the XSLT-Transformation on a DomDocument Object
DomXsltStylesheet->result_dump_file() -- Dumps the result from a XSLT-Transformation into a file
DomXsltStylesheet->result_dump_mem() -- Dumps the result from a XSLT-Transformation back into a string
domxml_new_doc -- Creates new empty XML document
domxml_open_file -- Creates a DOM object from an XML file
domxml_open_mem -- Creates a DOM object of an XML document
domxml_version -- Gets the XML library version
domxml_xmltree -- Creates a tree of PHP objects from an XML document
domxml_xslt_stylesheet_doc -- Creates a DomXsltStylesheet Object from a DomDocument Object
domxml_xslt_stylesheet_file -- Creates a DomXsltStylesheet Object from an XSL document in a file
domxml_xslt_stylesheet -- Creates a DomXsltStylesheet object from an XSL document in a string
domxml_xslt_version -- Gets the XSLT library version
xpath_eval_expression -- Evaluates the XPath Location Path in the given string
xpath_eval -- Evaluates the XPath Location Path in the given string
xpath_new_context -- Creates new xpath context
xpath_register_ns_auto -- Register the given namespace in the passed XPath context
xpath_register_ns -- Register the given namespace in the passed XPath context
xptr_eval -- Evaluate the XPtr Location Path in the given string
xptr_new_context -- Create new XPath Context