XXIX. DOM Functions

Introduction

The DOM extension is the replacement for the DOM XML extension from PHP 4. 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.

Installation

There is no installation needed to use these functions; they are part of the PHP core.

Predefined 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.

This module defines a number of classes, which are explained in the following tables. Classes with an equivalent in the DOM standard are named DOMxxx.

DOMAttr

Extends DOMNode. The DOMAttr interface represents an attribute in an DOMElement object.

Constructor

DOMAttr->__construct() - construct a new DOMAttr object

Methods

DOMAttr->isId() - Checks if attribute is a defined ID

Properties

Table 1.

Name	Type	Read-only	Description
name	string	yes	The name of the attribute
ownerElement	DOMElement	yes	The element which contains the attribute
schemaTypeInfo	bool	yes	Not implemented yet, always return `NULL`
specified	bool	yes	Not implemented yet, always return `NULL`
value	string	no	The value of the attribute

DOMCharacterData

Extends DOMNode.

Methods

DOMCharacterData->appendData() - Append a string to the end of the character data of the node
DOMCharacterData->deleteData() - Remove a range of characters from the node
DOMCharacterData->insertData() - Insert a string at the specified 16-bit unit offset
DOMCharacterData->replaceData() - Replace a substring within the DOMCharacterData node
DOMCharacterData->substringData() - Extracts a range of data from the node

Properties

Table 2.

Name	Type	Read-only	Description
data	string	no	The contents of the node
length	int	yes	The length of the contents

DOMComment

Extends DOMCharacterData.

Constructor

DOMComment->__construct() - construct a new DOMComment object

DOMDocument

Extends DOMNode.

Constructor

DOMDocument->__construct() - construct a new DOMDocument object

Methods

DOMDocument->createAttribute() - Create new attribute
DOMDocument->createAttributeNS() - Create new attribute node with an associated namespace
DOMDocument->createCDATASection() - Create new cdata node
DOMDocument->createComment() - Create new comment node
DOMDocument->createDocumentFragment() - Create new document fragment
DOMDocument->createElement() - Create new element node
DOMDocument->createElementNS() - Create new element node with an associated namespace
DOMDocument->createEntityReference() - Create new entity reference node
DOMDocument->createProcessingInstruction() - Creates new PI node
DOMDocument->createTextNode() - Create new text node
DOMDocument->getElementById() - Searches for an element with a certain id
DOMDocument->getElementsByTagName() - Searches for all elements with given tag name
DOMDocument->getElementsByTagNameNS() - Searches for all elements with given tag name in specified namespace
DOMDocument->importNode() - Import node into current document
DOMDocument->load() - Load XML from a file
DOMDocument->loadHTML() - Load HTML from a string
DOMDocument->loadHTMLFile() - Load HTML from a file
DOMDocument->loadXML() - Load XML from a string
DOMDocument->normalize() - Normalizes document
DOMDocument->relaxNGValidate() - Performs relaxNG validation on the document
DOMDocument->relaxNGValidateSource() - Performs relaxNG validation on the document
DOMDocument->save() - Dumps the internal XML tree back into a file
DOMDocument->saveHTML() - Dumps the internal document into a string using HTML formatting
DOMDocument->saveHTMLFile() - Dumps the internal document back into a file using HTML formatting
DOMDocument->saveXML() - Dumps the internal XML tree back into a string
DOMDocument->schemaValidate() - Validates a document based on a schema
DOMDocument->schemaValidateSource() - Validates a document based on a schema
DOMDocument->validate() - Validates the document based on its DTD
DOMDocument->xinclude() - Substitutes XIncludes in a DOMDocument Object

Properties

Table 3.

Name	Type	Read-only	Description
actualEncoding	string	yes
config	DOMConfiguration	yes
doctype	DOMDocumentType	yes	The Document Type Declaration associated with this document.
documentElement	DOMElement	yes	This is a convenience attribute that allows direct access to the child node that is the document element of the document.
documentURI	string	no	The location of the document or `NULL` if undefined.
encoding	string	no
formatOutput	bool	no
implementation	DOMImplementation	yes	The DOMImplementation object that handles this document.
preserveWhiteSpace	bool	no	Do not remove redundant white space. Default to `TRUE`.
recover	bool	no
resolveExternals	bool	no	Set it to `TRUE` to load external entities from a doctype declaration. This is useful for including character entities in your XML document.
standalone	bool	no
strictErrorChecking	bool	no	Throws DOMException on errors. Default to `TRUE`.
substituteEntities	bool	no
validateOnParse	bool	no	Loads and validates against the DTD. Default to `FALSE`.
version	string	no
xmlEncoding	string	yes	An attribute specifying, as part of the XML declaration, the encoding of this document. This is `NULL` when unspecified or when it is not known, such as when the Document was created in memory.
xmlStandalone	bool	no	An attribute specifying, as part of the XML declaration, whether this document is standalone. This is `FALSE` when unspecified.
xmlVersion	string	no	An attribute specifying, as part of the XML declaration, the version number of this document. If there is no declaration and if this document supports the "XML" feature, the value is "1.0".

DOMDocumentType

Extends DOMNode

Each DOMDocument has a doctype attribute whose value is either NULL or a DOMDocumentType object.

Properties

Table 4.

Name	Type	Read-only	Description
publicId	string	yes	The public identifier of the external subset.
systemId	string	yes	The system identifier of the external subset. This may be an absolute URI or not.
name	string	yes	The name of DTD; i.e., the name immediately following the `DOCTYPE` keyword.
entities	DOMNamedNodeMap	yes	A DOMNamedNodeMap containing the general entities, both external and internal, declared in the DTD.
notations	DOMNamedNodeMap	yes	A DOMNamedNodeMap containing the notations declared in the DTD.
internalSubset	string	yes	The internal subset as a string, or null if there is none. This is does not contain the delimiting square brackets.

DOMElement

Extends DOMNode.

Constructor

DOMElement->__construct() - construct a new DOMElement object

Methods

DOMElement->getAttribute() - Returns value of attribute
DOMElement->getAttributeNode() - Returns attribute node
DOMElement->getAttributeNodeNS() - Returns attribute node
DOMElement->getAttributeNS() - Returns value of attribute
DOMElement->getElementsByTagName() - Gets elements by tagname
DOMElement->getElementsByTagNameNS() - Get elements by namespaceURI and localName
DOMElement->hasAttribute() - Checks to see if attribute exists
DOMElement->hasAttributeNS() - Checks to see if attribute exists
DOMElement->removeAttribute() - Removes attribute
DOMElement->removeAttributeNode() - Removes attribute
DOMElement->removeAttributeNS() - Removes attribute
DOMElement->setAttribute() - Adds new attribute
DOMElement->setAttributeNode() - Adds new attribute node to element
DOMElement->setAttributeNodeNS() - Adds new attribute node to element
DOMElement->setAttributeNS() - Adds new attribute

Properties

Table 5.

Name	Type	Read-only	Description
schemaTypeInfo	bool	yes	Not implemented yet, always return `NULL`
tagName	string	yes	The element name

DOMEntity

Extends DOMNode

This interface represents a known entity, either parsed or unparsed, in an XML document.

Properties

Table 6.

Name	Type	Read-only	Description
publicId	string	yes	The public identifier associated with the entity if specified, and `NULL` otherwise.
systemId	string	yes	The system identifier associated with the entity if specified, and `NULL` otherwise. This may be an absolute URI or not.
notationName	string	yes	For unparsed entities, the name of the notation for the entity. For parsed entities, this is `NULL`.
actualEncoding	string	no	An attribute specifying the encoding used for this entity at the time of parsing, when it is an external parsed entity. This is `NULL` if it an entity from the internal subset or if it is not known.
encoding	string	yes	An attribute specifying, as part of the text declaration, the encoding of this entity, when it is an external parsed entity. This is `NULL` otherwise.
version	string	yes	An attribute specifying, as part of the text declaration, the version number of this entity, when it is an external parsed entity. This is `NULL` otherwise.

DOMEntityReference

Extends DOMNode.

Constructor

DOMEntityReference->__construct() - construct a new DOMEntityReference object

DOMException

DOM operations raise exceptions under particular circumstances, i.e., when an operation is impossible to perform for logical reasons.

Properties

Table 7.

Name	Type	Read-only	Description
code	int	yes	An integer indicating the type of error generated

DOMImplementation

The DOMImplementation interface provides a number of methods for performing operations that are independent of any particular instance of the document object model.

Constructor

DOMImplementation->__construct() - construct a new DOMImplementation object

Methods

DOMImplementation->createDocument() - Creates a DOM Document object of the specified type with its document element
DOMImplementation->createDocumentType() - Creates an empty DOMDocumentType object
DOMImplementation->hasFeature() - Test if the DOM implementation implements a specific feature

DOMNode

Methods

DOMNode->appendChild() - Adds new child at the end of the children
DOMNode->cloneNode() - Clones a node
DOMNode->hasAttributes() - Checks if node has attributes
DOMNode->hasChildNodes() - Checks if node has children
DOMNode->insertBefore() - Adds a new child before a reference node
DOMNode->isSameNode() - Indicates if two nodes are the same node
DOMNode->isSupported() - Checks if feature is supported for specified version
DOMNode->lookupNamespaceURI() - Returns namespace URI of the node based on the prefix
DOMNode->lookupPrefix() - Returns name space prefix of the node based on namespaceURI
DOMNode->normalize() - Normalizes the node
DOMNode->removeChild() - Removes child from list of children
DOMNode->replaceChild() - Replaces a child

Properties

Table 8.

Name	Type	Read-only	Description
nodeName	string	yes	Returns the most accurate name for the current node type
nodeValue	string	no	The value of this node, depending on its type.
nodeType	int	yes	Gets the type of the node. One of the predefined XML_xxx_NODE constants
parentNode	DOMNode	yes	The parent of this node.
childNodes	DOMNodeList	yes	A DOMNodeList that contains all children of this node. If there are no children, this is an empty DOMNodeList.
firstChild	DOMNode	yes	The first child of this node. If there is no such node, this returns `NULL`.
lastChild	DOMNode	yes	The last child of this node. If there is no such node, this returns `NULL`.
previousSibling	DOMNode	yes	The node immediately preceding this node. If there is no such node, this returns `NULL`.
nextSibling	DOMNode	yes	The node immediately following this node. If there is no such node, this returns `NULL`.
attributes	DOMNamedNodeMap	yes	A DOMNamedNodeMap containing the attributes of this node (if it is a DOMElement) or `NULL` otherwise.
ownerDocument	DOMDocument	yes	The DOMDocument object associated with this node.
namespaceURI	string	yes	The namespace URI of this node, or `NULL` if it is unspecified.
prefix	string	no	The namespace prefix of this node, or `NULL` if it is unspecified.
localName	string	yes	Returns the local part of the qualified name of this node.
baseURI	string	yes	The absolute base URI of this node or `NULL` if the implementation wasn't able to obtain an absolute URI.
textContent	string	no	This attribute returns the text content of this node and its descendants.

DOMNodeList

Methods

DOMNodelist->item() - Retrieves a node specified by index

Properties

Table 9.

Name	Type	Read-only	Description
length	int	yes	The number of nodes in the list. The range of valid child node indices is 0 to `length - 1` inclusive.

DOMNotation

Extends DOMNode

Properties

Table 10.

Name	Type	Read-only	Description
publicId	string	yes
systemId	string	yes

DOMProcessingInstruction

Extends DOMNode.

Constructor

DOMProcessingInstruction->__construct() - construct a new DOMProcessingInstruction object

Properties

Table 11.

Name	Type	Read-only	Description
target	string	yes
data	string	no

DOMText

Extends DOMCharacterData.

Constructor

DOMText->__construct() - construct a new DOMText object

Methods

DOMText->isWhitespaceInElementContent() - Indicates whether this text node contains whitespace
DOMText->splitText() - Breaks the node into two nodes at the specified offset

Properties

Table 12.

Name	Type	Read-only	Description
wholeText	string	yes

DOMXPath

Constructor

DOMXPath->__construct() - construct a new DOMXPath object

Methods

DOMXPath->registerNamespace() - Registers the namespace with the DOMXpath object
DOMXPath->evaluate() - Evaluates the given XPath expression and returns a typed result if possible
DOMXPath->query() - Evaluates the given XPath expression

Properties

Table 13.

Name	Type	Read-only	Description
document	DOMDocument

Examples

Many examples in this reference require an XML file. We will use book.xml that contains the following:

Example 1. chapter.xml

<?xml version="1.0" encoding="iso-8859-1"?>
<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN"
 "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd" [
]>
<book id="listing">
 <title>My lists</title>
 <chapter id="books">
  <title>My books</title>
  <para>
   <informaltable>
    <tgroup cols="4">
     <thead>
      <row>
       <entry>Title</entry>
       <entry>Author</entry>
       <entry>Language</entry>
       <entry>ISBN</entry>
      </row>
     </thead>
     <tbody>
      <row>
       <entry>The Grapes of Wrath</entry>
       <entry>John Steinbeck</entry>
       <entry>en</entry>
       <entry>0140186409</entry>
      </row>
      <row>
       <entry>The Pearl</entry>
       <entry>John Steinbeck</entry>
       <entry>en</entry>
       <entry>014017737X</entry>
      </row>
      <row>
       <entry>Samarcande</entry>
       <entry>Amine Maalouf</entry>
       <entry>fr</entry>
       <entry>2253051209</entry>
      </row>
      <!-- TODO: I have a lot of remaining books to add.. -->
     </tbody>
    </tgroup>
   </informaltable>
  </para>
 </chapter>
</book>

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 14. XML constants

Constant	Value	Description
`XML_ELEMENT_NODE` (integer)	1	Node is a DOMElement
`XML_ATTRIBUTE_NODE` (integer)	2	Node is a DOMAttr
`XML_TEXT_NODE` (integer)	3	Node is a DOMText
`XML_CDATA_SECTION_NODE` (integer)	4	Node is a DOMCharacterData
`XML_ENTITY_REF_NODE` (integer)	5	Node is a DOMEntityReference
`XML_ENTITY_NODE` (integer)	6	Node is a DOMEntity
`XML_PI_NODE` (integer)	7	Node is a DOMProcessingInstruction
`XML_COMMENT_NODE` (integer)	8	Node is a DOMComment
`XML_DOCUMENT_NODE` (integer)	9	Node is a DOMDocument
`XML_DOCUMENT_TYPE_NODE` (integer)	10	Node is a DOMDocumentType
`XML_DOCUMENT_FRAG_NODE` (integer)	11	Node is a DOMDocumentFragment
`XML_NOTATION_NODE` (integer)	12	Node is a DOMNotation
`XML_HTML_DOCUMENT_NODE` (integer)	13
`XML_DTD_NODE` (integer)	14
`XML_ELEMENT_DECL_NODE` (integer)	15
`XML_ATTRIBUTE_DECL_NODE` (integer)	16
`XML_ENTITY_DECL_NODE` (integer)	17
`XML_NAMESPACE_DECL_NODE` (integer)	18
`XML_ATTRIBUTE_CDATA` (integer)	1
`XML_ATTRIBUTE_ID` (integer)	2
`XML_ATTRIBUTE_IDREF` (integer)	3
`XML_ATTRIBUTE_IDREFS` (integer)	4
`XML_ATTRIBUTE_ENTITY` (integer)	5
`XML_ATTRIBUTE_NMTOKEN` (integer)	7
`XML_ATTRIBUTE_NMTOKENS` (integer)	8
`XML_ATTRIBUTE_ENUMERATION` (integer)	9
`XML_ATTRIBUTE_NOTATION` (integer)	10

Table 15. DOMException constants

Constant	Value	Description
`DOM_INDEX_SIZE_ERR` (integer)	1	If index or size is negative, or greater than the allowed value.
`DOMSTRING_SIZE_ERR` (integer)	2	If the specified range of text does not fit into a DOMString.
`DOM_HIERARCHY_REQUEST_ERR` (integer)	3	If any node is inserted somewhere it doesn't belong
`DOM_WRONG_DOCUMENT_ERR` (integer)	4	If a node is used in a different document than the one that created it.
`DOM_INVALID_CHARACTER_ERR` (integer)	5	If an invalid or illegal character is specified, such as in a name.
`DOM_NO_DATA_ALLOWED_ERR` (integer)	6	If data is specified for a node which does not support data.
`DOM_NO_MODIFICATION_ALLOWED_ERR` (integer)	7	If an attempt is made to modify an object where modifications are not allowed.
`DOM_NOT_FOUND_ERR` (integer)	8	If an attempt is made to reference a node in a context where it does not exist.
`DOM_NOT_SUPPORTED_ERR` (integer)	9	If the implementation does not support the requested type of object or operation.
`DOM_INUSE_ATTRIBUTE_ERR` (integer)	10	If an attempt is made to add an attribute that is already in use elsewhere.
`DOM_INVALID_STATE_ERR` (integer)	11	If an attempt is made to use an object that is not, or is no longer, usable.
`DOM_SYNTAX_ERR` (integer)	12	If an invalid or illegal string is specified.
`DOM_INVALID_MODIFICATION_ERR` (integer)	13	If an attempt is made to modify the type of the underlying object.
`DOM_NAMESPACE_ERR` (integer)	14	If an attempt is made to create or change an object in a way which is incorrect with regard to namespaces.
`DOM_INVALID_ACCESS_ERR` (integer)	15	If a parameter or an operation is not supported by the underlying object.
`DOM_VALIDATION_ERR` (integer)	16	If a call to a method such as insertBefore or removeChild would make the Node invalid with respect to "partial validity", this exception would be raised and the operation would not be done.

Table of Contents
DOMAttr->__construct() -- Creates a new DOMAttr object
DOMAttr->isId() -- Checks if attribute is a defined ID
DOMCharacterData->appendData() -- Append the string to the end of the character data of the node
DOMCharacterData->deleteData() -- Remove a range of characters from the node
DOMCharacterData->insertData() -- Insert a string at the specified 16-bit unit offset
DOMCharacterData->replaceData() -- Replace a substring within the DOMCharacterData node
DOMCharacterData->substringData() -- Extracts a range of data from the node
DOMComment->__construct() -- Creates a new DOMComment object
DOMDocument->__construct() -- Creates a new DOMDocument object
DOMDocument->createAttribute() -- Create new attribute
DOMDocument->createAttributeNS() -- Create new attribute node with an associated namespace
DOMDocument->createCDATASection() -- Create new cdata node
DOMDocument->createComment() -- Create new comment node
DOMDocument->createDocumentFragment() -- Create new document fragment
DOMDocument->createElement() -- Create new element node
DOMDocument->createElementNS() -- Create new element node with an associated namespace
DOMDocument->createEntityReference() -- Create new entity reference node
DOMDocument->createProcessingInstruction() -- Creates new PI node
DOMDocument->createTextNode() -- Create new text node
DOMDocument->getElementById() -- Searches for an element with a certain id
DOMDocument->getElementsByTagName() -- Searches for all elements with given tag name
DOMDocument->getElementsByTagNameNS() -- Searches for all elements with given tag name in specified namespace
DOMDocument->importNode() -- Import node into current document
DOMDocument->load() -- Load XML from a file
DOMDocument->loadHTML() -- Load HTML from a string
DOMDocument->loadHTMLFile() -- Load HTML from a file
DOMDocument->loadXML() -- Load XML from a string
DOMDocument->normalize() -- Normalizes the document
DOMDocument->relaxNGValidate() -- Performs relaxNG validation on the document
DOMDocument->relaxNGValidateSource() -- Performs relaxNG validation on the document
DOMDocument->save() -- Dumps the internal XML tree back into a file
DOMDocument->saveHTML() -- Dumps the internal document into a string using HTML formatting
DOMDocument->saveHTMLFile() -- Dumps the internal document into a file using HTML formatting
DOMDocument->saveXML() -- Dumps the internal XML tree back into a string
DOMDocument->schemaValidate() -- Validates a document based on a schema
DOMDocument->schemaValidateSource() -- Validates a document based on a schema
DOMDocument->validate() -- Validates the document based on its DTD
DOMDocument->xinclude() -- Substitutes XIncludes in a DOMDocument Object
DOMDocumentFragment->appendXML() -- Append XML data
DOMElement->__construct() -- Creates a new DOMElement object
DOMElement->getAttribute() -- Returns value of attribute
DOMElement->getAttributeNode() -- Returns attribute node
DOMElement->getAttributeNodeNS() -- Returns attribute node
DOMElement->getAttributeNS() -- Returns value of attribute
DOMElement->getElementsByTagName() -- Gets elements by tagname
DOMElement->getElementsByTagNameNS() -- Get elements by namespaceURI and localName
DOMElement->hasAttribute() -- Checks to see if attribute exists
DOMElement->hasAttributeNS() -- Checks to see if attribute exists
DOMElement->removeAttribute() -- Removes attribute
DOMElement->removeAttributeNode() -- Removes attribute
DOMElement->removeAttributeNS() -- Removes attribute
DOMElement->setAttribute() -- Adds new attribute
DOMElement->setAttributeNode() -- Adds new attribute node to element
DOMElement->setAttributeNodeNS() -- Adds new attribute node to element
DOMElement->setAttributeNS() -- Adds new attribute
DOMEntityReference->__construct() -- Creates a new DOMEntityReference object
DOMImplementation->__construct() -- Creates a new DOMImplementation object
DOMImplementation->createDocument() -- Creates a DOMDocument object of the specified type with its document element
DOMImplementation->createDocumentType() -- Creates an empty DOMDocumentType object
DOMImplementation->hasFeature() -- Test if the DOM implementation implements a specific feature
DOMNamedNodeMap->getNamedItem() -- Retrieves a node specified by name
DOMNamedNodeMap->getNamedItemNS() -- Retrieves a node specified by local name and namespace URI
DOMNamedNodeMap->item() -- Retrieves a node specified by index
DOMNode->appendChild() -- Adds new child at the end of the children
DOMNode->cloneNode() -- Clones a node
DOMNode->hasAttributes() -- Checks if node has attributes
DOMNode->hasChildNodes() -- Checks if node has children
DOMNode->insertBefore() -- Adds a new child before a reference node
DOMNode->isSameNode() -- Indicates if two nodes are the same node
DOMNode->isSupported() -- Checks if feature is supported for specified version
DOMNode->lookupNamespaceURI() -- Gets the namespace URI of the node based on the prefix
DOMNode->lookupPrefix() -- Gets the namespace prefix of the node based on the namespace URI
DOMNode->normalize() -- Normalizes the node
DOMNode->removeChild() -- Removes child from list of children
DOMNode->replaceChild() -- Replaces a child
DOMNodelist->item() -- Retrieves a node specified by index
DOMProcessingInstruction->__construct() -- Creates a new DOMProcessingInstruction object
DOMText->__construct() -- Creates a new DOMText object
DOMText->isWhitespaceInElementContent() -- Indicates whether this text node contains whitespace
DOMText->splitText() -- Breaks this node into two nodes at the specified offset
DOMXPath->__construct() -- Creates a new DOMXPath object
DOMXPath->evaluate() -- Evaluates the given XPath expression and returns a typed result if possible.
DOMXPath->query() -- Evaluates the given XPath expression
DOMXPath->registerNamespace() -- Registers the namespace with the DOMXPath object
dom_import_simplexml -- Gets a DOMElement object from a SimpleXMLElement object