This specification defines the Document Object Model Core Level 3, a platform- and language-neutral interface that allows programs and scripts to dynamically access and update the content, structure and style of documents. The Document Object Model Core Level 3 builds on the Document Object Model Core Level 2.

1. Document Object Model Core

Editors: Arnaud Le Hors, IBM; Gavin Nicol, Inso EPS (for DOM Level 1); Lauren Wood, SoftQuad, Inc. (for DOM Level 1); Mike Champion, ArborText (for DOM Level 1 from November 20, 1997); Steve Byrne, JavaSoft (for DOM Level 1 until November 19, 1997)

1.1. Overview of the DOM Core Interfaces

This section defines a set of objects and interfaces for accessing and manipulating document objects. The functionality specified in this section (the Core functionality) is sufficient to allow software developers and web script authors to access and manipulate parsed HTML and XML content inside conforming products. The DOM Core API also allows creation and population of a Document object using only DOM API calls; loading a Document and saving it persistently is left to the product that implements the DOM API.

1.1.1. The DOM Structure Model

The DOM presents documents as a hierarchy of Node objects that also implement other, more specialized interfaces. Some types of nodes may have child nodes of various types, and others are leaf nodes that cannot have anything below them in the document structure. For XML and HTML, the node types, and which node types they may have as children, are as follows:

Document -- Element (maximum of one), ProcessingInstruction, Comment, DocumentType (maximum of one)
DocumentFragment -- Element, ProcessingInstruction, Comment, Text, CDATASection, EntityReference
DocumentType -- no children
EntityReference -- Element, ProcessingInstruction, Comment, Text, CDATASection, EntityReference
Element -- Element, Text, Comment, ProcessingInstruction, CDATASection, EntityReference
Attr -- Text, EntityReference
ProcessingInstruction -- no children
Comment -- no children
Text -- no children
CDATASection -- no children
Entity -- Element, ProcessingInstruction, Comment, Text, CDATASection, EntityReference
Notation -- no children

The DOM also specifies a NodeList interface to handle ordered lists of Nodes, such as the children of a Node, or the elements returned by the getElementsByTagName method of the Element interface, and also a NamedNodeMap interface to handle unordered sets of nodes referenced by their name attribute, such as the attributes of an Element. NodeList and NamedNodeMap objects in the DOM are live; that is, changes to the underlying document structure are reflected in all relevant NodeList and NamedNodeMap objects. For example, if a DOM user gets a NodeList object containing the children of an Element, then subsequently adds more children to that element (or removes children, or modifies them), those changes are automatically reflected in the NodeList, without further action on the user's part. Likewise, changes to a Node in the tree are reflected in all references to that Node in NodeList and NamedNodeMap objects.

Finally, the interfaces Text, Comment, and CDATASection all inherit from the CharacterData interface.

1.1.2. Memory Management

Most of the APIs defined by this specification are interfaces rather than classes. That means that an implementation need only expose methods with the defined names and specified operation, not implement classes that correspond directly to the interfaces. This allows the DOM APIs to be implemented as a thin veneer on top of legacy applications with their own data structures, or on top of newer applications with different class hierarchies. This also means that ordinary constructors (in the Java or C++ sense) cannot be used to create DOM objects, since the underlying objects to be constructed may have little relationship to the DOM interfaces. The conventional solution to this in object-oriented design is to define factory methods that create instances of objects that implement the various interfaces. Objects implementing some interface "X" are created by a "createX()" method on the Document interface; this is because all DOM objects live in the context of a specific Document.

The Core DOM APIs are designed to be compatible with a wide range of languages, including both general-user scripting languages and the more challenging languages used mostly by professional programmers. Thus, the DOM APIs need to operate across a variety of memory management philosophies, from language bindings that do not expose memory management to the user at all, through those (notably Java) that provide explicit constructors but provide an automatic garbage collection mechanism to automatically reclaim unused memory, to those (especially C/C++) that generally require the programmer to explicitly allocate object memory, track where it is used, and explicitly free it for re-use. To ensure a consistent API across these platforms, the DOM does not address memory management issues at all, but instead leaves these for the implementation. Neither of the explicit language bindings defined by the DOM API (for ECMAScript and Java) require any memory management methods, but DOM bindings for other languages (especially C or C++) may require such support. These extensions will be the responsibility of those adapting the DOM API to a specific language, not the DOM Working Group.

1.1.3. Naming Conventions

While it would be nice to have attribute and method names that are short, informative, internally consistent, and familiar to users of similar APIs, the names also should not clash with the names in legacy APIs supported by DOM implementations. Furthermore, both OMG IDL and ECMAScript have significant limitations in their ability to disambiguate names from different namespaces that make it difficult to avoid naming conflicts with short, familiar names. So, DOM names tend to be long and descriptive in order to be unique across all environments.

The Working Group has also attempted to be internally consistent in its use of various terms, even though these may not be common distinctions in other APIs. For example, the DOM API uses the method name "remove" when the method changes the structural model, and the method name "delete" when the method gets rid of something inside the structure model. The thing that is deleted is not returned. The thing that is removed may be returned, when it makes sense to return it.

1.1.4. Inheritance vs. Flattened Views of the API

The DOM Core APIs present two somewhat different sets of interfaces to an XML/HTML document: one presenting an "object oriented" approach with a hierarchy of inheritance, and a "simplified" view that allows all manipulation to be done via the Node interface without requiring casts (in Java and other C-like languages) or query interface calls in COM environments. These operations are fairly expensive in Java and COM, and the DOM may be used in performance-critical environments, so we allow significant functionality using just the Node interface. Because many other users will find the inheritance hierarchy easier to understand than the "everything is a Node" approach to the DOM, we also support the full higher-level interfaces for those who prefer a more object-oriented API.

In practice, this means that there is a certain amount of redundancy in the API. The Working Group considers the "inheritance" approach the primary view of the API, and the full set of functionality on Node to be "extra" functionality that users may employ, but that does not eliminate the need for methods on other interfaces that an object-oriented analysis would dictate. (Of course, when the O-O analysis yields an attribute or method that is identical to one on the Node interface, we don't specify a completely redundant one.) Thus, even though there is a generic nodeName attribute on the Node interface, there is still a tagName attribute on the Element interface; these two attributes must contain the same value, but the it is worthwhile to support both, given the different constituencies the DOM API must satisfy.

1.1.5. The `DOMString` type

To ensure interoperability, the DOM specifies the following:

Type Definition DOMString

A DOMString is a sequence of 16-bit units.

IDL Definition

valuetype DOMString sequence<unsigned short>;

Applications must encode DOMString using UTF-16 (defined in [Unicode] and Amendment 1 of [ISO/IEC 10646]).

The UTF-16 encoding was chosen because of its widespread industry practice. Note that for both HTML and XML, the document character set (and therefore the notation of numeric character references) is based on UCS [ISO-10646]. A single numeric character reference in a source document may therefore in some cases correspond to two 16-bit units in a DOMString (a high surrogate and a low surrogate).

Note: Even though the DOM defines the name of the string type to be DOMString, bindings may use different names. For example for Java, DOMString is bound to the String type because it also uses UTF-16 as its encoding.

Note: As of August 2000, the OMG IDL specification ([OMGIDL]) included a wstring type. However, that definition did not meet the interoperability criteria of the DOM API since it relied on negotiation to decide the width and encoding of a character.

1.1.6. The `DOMTimeStamp` type

To ensure interoperability, the DOM specifies the following:

Type Definition DOMTimeStamp

A DOMTimeStamp represents a number of milliseconds.

IDL Definition

typedef unsigned long long DOMTimeStamp;

Note: Even though the DOM uses the type DOMTimeStamp, bindings may use different types. For example for Java, DOMTimeStamp is bound to the long type. In ECMAScript, TimeStamp is bound to the Date type because the range of the integer type is too small.

1.1.7. The `DOMKey` type

To ensure interoperability, the DOM specifies the following:

Type Definition DOMKey

A DOMKey is a unique key generated by the DOM implementation to uniquely identify DOM nodes.

IDL Definition

typedef Object DOMKey;

Note: Even though the DOM uses the type DOMKey, bindings may use different types. For example for Java, DOMKey is bound to the Object type. In ECMAScript, DOMKey is bound to the Number type.

1.1.8. String comparisons in the DOM

The DOM has many interfaces that imply string matching. HTML processors generally assume an uppercase (less often, lowercase) normalization of names for such things as elements, while XML is explicitly case sensitive. For the purposes of the DOM, string matching is performed purely by binary comparison of the 16-bit units of the DOMString. In addition, the DOM assumes that any case normalizations take place in the processor, before the DOM structures are built.

Note: Besides case folding, there are additional normalizations that can be applied to text. The W3C I18N Working Group is in the process of defining exactly which normalizations are necessary, and where they should be applied. The W3C I18N Working Group expects to require early normalization, which means that data read into the DOM is assumed to already be normalized. The DOM and applications built on top of it in this case only have to assure that text remains normalized when being changed. For further details, please see [Charmod].

1.1.9. XML Namespaces

The DOM Level 2 (and higher) supports XML namespaces [Namespaces] by augmenting several interfaces of the DOM Level 1 Core to allow creating and manipulating elements and attributes associated to a namespace.

As far as the DOM is concerned, special attributes used for declaring XML namespaces are still exposed and can be manipulated just like any other attribute. However, nodes are permanently bound to namespace URIs as they get created. Consequently, moving a node within a document, using the DOM, in no case results in a change of its namespace prefix or namespace URI. Similarly, creating a node with a namespace prefix and namespace URI, or changing the namespace prefix of a node, does not result in any addition, removal, or modification of any special attributes for declaring the appropriate XML namespaces. Namespace validation is not enforced; the DOM application is responsible. In particular, since the mapping between prefixes and namespace URIs is not enforced, in general, the resulting document cannot be serialized naively. For example, applications may have to declare every namespace in use when serializing a document.

DOM Level 2 (and higher) doesn't perform any URI normalization or canonicalization. The URIs given to the DOM are assumed to be valid (e.g., characters such as whitespaces are properly escaped), and no lexical checking is performed. Absolute URI references are treated as strings and compared literally. How relative namespace URI references are treated is undefined. To ensure interoperability only absolute namespace URI references (i.e., URI references beginning with a scheme name and a colon) should be used. Note that because the DOM does no lexical checking, the empty string will be treated as a real namespace URI in DOM Level 2 methods. Applications must use the value null as the namespaceURI parameter for methods if they wish to have no namespace.

Note: In the DOM, all namespace declaration attributes are by definition bound to the namespace URI: "http://www.w3.org/2000/xmlns/". These are the attributes whose namespace prefix or qualified name is "xmlns". Although, at the time of writing, this is not part of the XML Namespaces specification [Namespaces], it is planned to be incorporated in a future revision.

In a document with no namespaces, the child list of an EntityReference node is always the same as that of the corresponding Entity. This is not true in a document where an entity contains unbound namespace prefixes. In such a case, the descendants of the corresponding EntityReference nodes may be bound to different namespace URIs, depending on where the entity references are. Also, because, in the DOM, nodes always remain bound to the same namespace URI, moving such EntityReference nodes can lead to documents that cannot be serialized. This is also true when the DOM Level 1 method createEntityReference of the Document interface is used to create entity references that correspond to such entities, since the descendants of the returned EntityReference are unbound. The DOM Level 2 does not support any mechanism to resolve namespace prefixes. For all of these reasons, use of such entities and entity references should be avoided or used with extreme care. A future Level of the DOM may include some additional support for handling these.

The new methods, such as createElementNS and createAttributeNS of the Document interface, are meant to be used by namespace aware applications. Simple applications that do not use namespaces can use the DOM Level 1 methods, such as createElement and createAttribute. Elements and attributes created in this way do not have any namespace prefix, namespace URI, or local name.

Note: DOM Level 1 methods are namespace ignorant. Therefore, while it is safe to use these methods when not dealing with namespaces, using them and the new ones at the same time should be avoided. DOM Level 1 methods solely identify attribute nodes by their nodeName. On the contrary, the DOM Level 2 methods related to namespaces, identify attribute nodes by their namespaceURI and localName. Because of this fundamental difference, mixing both sets of methods can lead to unpredictable results. In particular, using setAttributeNS, an element may have two attributes (or more) that have the same nodeName, but different namespaceURIs. Calling getAttribute with that nodeName could then return any of those attributes. The result depends on the implementation. Similarly, using setAttributeNode, one can set two attributes (or more) that have different nodeNames but the same prefix and namespaceURI. In this case getAttributeNodeNS will return either attribute, in an implementation dependent manner. The only guarantee in such cases is that all methods that access a named item by its nodeName will access the same item, and all methods which access a node by its URI and local name will access the same node. For instance, setAttribute and setAttributeNS affect the node that getAttribute and getAttributeNS, respectively, return.

1.1.10. Mutiple XML Datatypes in a DOM Document

As new XML vocabularies are developed, those defining the vocabularies are also beginning to define specialized APIs for manipulating XML instances of those vocabularies. This is usually done by extending the DOM to provide interfaces and methods that perform operations frequently needed their users. For example, the MathML [@@link] and SVG [@@link] specifications are developing DOM extensions to allow users to manipulate instances of these vocabularies using semantics appropriate to images and mathematics (respectively) as well as the generic DOM XML semantics. Instances of SVG or MathML are often embedded in XML documents conforming to a different schema such as XHTML.

While the XML Namespaces Recommendation provides a mechanism for integrating these documents at the syntax level, it has become clear that the DOM Level 2 Recommendation [@@link] is not rich enough to cover all the issues that have been encountered in having these different DOM implementations be used together in a single application. DOM Level 3 deals with the requirements brought about by embedding fragments written according to a specific markup language (the embedded component) in a document where the rest of the markup is not written according to that specific markup language (the host document). It does not deal with fragments embedded by reference or linking.

A DOM implementation supporting DOM Level 3 Core should be able to collaborate with subcomponents implementing specific DOMs to assemble a compound document that can be traversed and manipulated via DOM interfaces as if it were a seamless whole.

The normal typecast operation on an object should support the interfaces expected by legacy code for a given document type. Typecasting techniques may not be adequate for selecting between multiple DOM specializations of an object which were combined at run time, because they may not all be part of the same object as defined by the binding's object model. Conflicts are most obvious with the Document object, since it is shared as owner by the rest of the document. In a homogeneous document, elements rely on the Document for specialized services and construction of specialized nodes. In a heterogeneous document, elements from different modules expect different services and APIs from the same Document object, since there can only be one owner and root of the document hierarchy.

1.2. Fundamental Interfaces

The interfaces within this section are considered fundamental, and must be fully implemented by all conforming implementations of the DOM, including all HTML DOM implementations [DOM Level 1], unless otherwise specified.

(ED: change link to DOM Level 2 HTML when available)

A DOM application may use the hasFeature(feature, version) method of the DOMImplementation interface with parameter values "Core" and "3.0" (respectively) to determine whether or not this module is supported by the implementation. Any implementation that conforms to DOM Level 3 or a DOM Level 3 module must conform to the Core module.

Exception DOMException

DOM operations only raise exceptions in "exceptional" circumstances, i.e., when an operation is impossible to perform (either for logical reasons, because data is lost, or because the implementation has become unstable). In general, DOM methods return specific error values in ordinary processing situations, such as out-of-bound errors when using NodeList.

Implementations should raise other exceptions under other circumstances. For example, implementations should raise an implementation-dependent exception if a null argument is passed.

Some languages and object systems do not support the concept of exceptions. For such systems, error conditions may be indicated using native error reporting mechanisms. For some bindings, for example, methods may return error codes similar to those listed in the corresponding method descriptions.

IDL Definition

exception DOMException {
  unsigned short   code;
};
// ExceptionCode
const unsigned short      INDEX_SIZE_ERR                 = 1;
const unsigned short      DOMSTRING_SIZE_ERR             = 2;
const unsigned short      HIERARCHY_REQUEST_ERR          = 3;
const unsigned short      WRONG_DOCUMENT_ERR             = 4;
const unsigned short      INVALID_CHARACTER_ERR          = 5;
const unsigned short      NO_DATA_ALLOWED_ERR            = 6;
const unsigned short      NO_MODIFICATION_ALLOWED_ERR    = 7;
const unsigned short      NOT_FOUND_ERR                  = 8;
const unsigned short      NOT_SUPPORTED_ERR              = 9;
const unsigned short      INUSE_ATTRIBUTE_ERR            = 10;
// Introduced in DOM Level 2:
const unsigned short      INVALID_STATE_ERR              = 11;
// Introduced in DOM Level 2:
const unsigned short      SYNTAX_ERR                     = 12;
// Introduced in DOM Level 2:
const unsigned short      INVALID_MODIFICATION_ERR       = 13;
// Introduced in DOM Level 2:
const unsigned short      NAMESPACE_ERR                  = 14;
// Introduced in DOM Level 2:
const unsigned short      INVALID_ACCESS_ERR             = 15;

Definition group ExceptionCode

An integer indicating the type of error generated.

Note: Other numeric codes are reserved for W3C for possible future use.

Defined Constants

DOMSTRING_SIZE_ERR: If the specified range of text does not fit into a DOMString
HIERARCHY_REQUEST_ERR: If any node is inserted somewhere it doesn't belong
INDEX_SIZE_ERR: If index or size is negative, or greater than the allowed value
INUSE_ATTRIBUTE_ERR: If an attempt is made to add an attribute that is already in use elsewhere
INVALID_ACCESS_ERR, introduced in DOM Level 2.: If a parameter or an operation is not supported by the underlying object.
INVALID_CHARACTER_ERR: If an invalid or illegal character is specified, such as in a name. See production 2 in the XML specification for the definition of a legal character, and production 5 for the definition of a legal name character.
INVALID_MODIFICATION_ERR, introduced in DOM Level 2.: If an attempt is made to modify the type of the underlying object.
INVALID_STATE_ERR, introduced in DOM Level 2.: If an attempt is made to use an object that is not, or is no longer, usable.
NAMESPACE_ERR, introduced in DOM Level 2.: If an attempt is made to create or change an object in a way which is incorrect with regard to namespaces.
NOT_FOUND_ERR: If an attempt is made to reference a node in a context where it does not exist
NOT_SUPPORTED_ERR: If the implementation does not support the requested type of object or operation.
NO_DATA_ALLOWED_ERR: If data is specified for a node which does not support data
NO_MODIFICATION_ALLOWED_ERR: If an attempt is made to modify an object where modifications are not allowed
SYNTAX_ERR, introduced in DOM Level 2.: If an invalid or illegal string is specified.
WRONG_DOCUMENT_ERR: If a node is used in a different document than the one that created it (that doesn't support it)

Interface DOMImplementation

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

IDL Definition

interface DOMImplementation {
  boolean            hasFeature(in DOMString feature, 
                                in DOMString version);
  // Introduced in DOM Level 2:
  DocumentType       createDocumentType(in DOMString qualifiedName, 
                                        in DOMString publicId, 
                                        in DOMString systemId)
                                        raises(DOMException);
  // Introduced in DOM Level 2:
  Document           createDocument(in DOMString namespaceURI, 
                                    in DOMString qualifiedName, 
                                    in DocumentType doctype)
                                        raises(DOMException);
  // Introduced in DOM Level 3:
  DOMImplementation  getAs(in DOMString feature);
};

Methods

createDocument introduced in DOM Level 2

Creates a DOM Document object of the specified type with its document element.

Parameters

namespaceURI of type DOMString: The namespace URI of the document element to create.
qualifiedName of type DOMString: The qualified name of the document element to be created.
doctype of type DocumentType: The type of document to be created or null.
When doctype is not null, its Node.ownerDocument attribute is set to the document being created.

Return Value

Document

A new Document object.

Exceptions

DOMException

INVALID_CHARACTER_ERR: Raised if the specified qualified name contains an illegal character.

NAMESPACE_ERR: Raised if the qualifiedName is malformed, if the qualifiedName has a prefix and the namespaceURI is null, or if the qualifiedName has a prefix that is "xml" and the namespaceURI is different from "http://www.w3.org/XML/1998/namespace" [Namespaces], or if the DOM implementation does not support the "XML" feature but a non-null namespace URI was provided, since namespaces were defined by XML.

WRONG_DOCUMENT_ERR: Raised if doctype has already been used with a different document or was created from a different implementation.

NOT_SUPPORTED_ERR: May be raised by DOM implementations which do not support the "XML" feature, if they choose not to support this method.

Note: Other features introduced in the future, by the DOM WG or in extensions defined by other groups, may also demand support for this method; please consult the definition of the feature to see if it requires this method.

createDocumentType introduced in DOM Level 2

Creates an empty DocumentType node. Entity declarations and notations are not made available. Entity reference expansions and default attribute additions do not occur. It is expected that a future version of the DOM will provide a way for populating a DocumentType.

Parameters

qualifiedName of type DOMString: The qualified name of the document type to be created.
publicId of type DOMString: The external subset public identifier.
systemId of type DOMString: The external subset system identifier.

Return Value

DocumentType

A new DocumentType node with Node.ownerDocument set to null.

Exceptions

DOMException

INVALID_CHARACTER_ERR: Raised if the specified qualified name contains an illegal character.

NAMESPACE_ERR: Raised if the qualifiedName is malformed.

NOT_SUPPORTED_ERR: May be raised by DOM implementations which do not support the "XML" feature, if they choose not to support this method.

getAs introduced in DOM Level 3

This method makes available a DOMImplementation's specialized interface (see Mutiple XML Datatypes in a DOM Document).

Parameters

feature of type DOMString: The name of the feature requested (case-insensitive).

Return Value

DOMImplementation

Returns an alternate DOMImplementation which implements the specialized APIs of the specified feature, if any, or the current DOMImplementation if there is no alternate DOMImplementation object which implements interfaces associated with that feature. Any alternate DOMImplementation returned by this method must delegate to the primary core DOMImplementation and not return results inconsistent with the primary DOMImplementation

No Exceptions

hasFeature

Test if the DOM implementation implements a specific feature.

Parameters

feature of type DOMString: The name of the feature to test (case-insensitive). The values used by DOM features are defined throughout the DOM Level 2 specifications and listed in the Conformance
(ED: Add link when available)
section. The name must be an XML name. To avoid possible conflicts, as a convention, names referring to features defined outside the DOM specification should be made unique.
version of type DOMString: This is the version number of the feature to test. In Level 2, the string can be either "2.0" or "1.0". If the version is not specified, supporting any version of the feature causes the method to return true.

Return Value

boolean

true if the feature is implemented in the specified version, false otherwise.

No Exceptions

Interface DocumentFragment

DocumentFragment is a "lightweight" or "minimal" Document object. It is very common to want to be able to extract a portion of a document's tree or to create a new fragment of a document. Imagine implementing a user command like cut or rearranging a document by moving fragments around. It is desirable to have an object which can hold such fragments and it is quite natural to use a Node for this purpose. While it is true that a Document object could fulfill this role, a Document object can potentially be a heavyweight object, depending on the underlying implementation. What is really needed for this is a very lightweight object. DocumentFragment is such an object.

Furthermore, various operations -- such as inserting nodes as children of another Node -- may take DocumentFragment objects as arguments; this results in all the child nodes of the DocumentFragment being moved to the child list of this node.

The children of a DocumentFragment node are zero or more nodes representing the tops of any sub-trees defining the structure of the document. DocumentFragment nodes do not need to be well-formed XML documents (although they do need to follow the rules imposed upon well-formed XML parsed entities, which can have multiple top nodes). For example, a DocumentFragment might have only one child and that child node could be a Text node. Such a structure model represents neither an HTML document nor a well-formed XML document.

When a DocumentFragment is inserted into a Document (or indeed any other Node that may take children) the children of the DocumentFragment and not the DocumentFragment itself are inserted into the Node. This makes the DocumentFragment very useful when the user wishes to create nodes that are siblings; the DocumentFragment acts as the parent of these nodes so that the user can use the standard methods from the Node interface, such as insertBefore and appendChild.

IDL Definition

interface DocumentFragment : Node {
};

Interface Document

The Document interface represents the entire HTML or XML document. Conceptually, it is the root of the document tree, and provides the primary access to the document's data.

Since elements, text nodes, comments, processing instructions, etc. cannot exist outside the context of a Document, the Document interface also contains the factory methods needed to create these objects. The Node objects created have a ownerDocument attribute which associates them with the Document within whose context they were created.

IDL Definition

interface Document : Node {
  readonly attribute DocumentType     doctype;
  readonly attribute DOMImplementation  implementation;
  readonly attribute Element          documentElement;
  Element            createElement(in DOMString tagName)
                                        raises(DOMException);
  DocumentFragment   createDocumentFragment();
  Text               createTextNode(in DOMString data);
  Comment            createComment(in DOMString data);
  CDATASection       createCDATASection(in DOMString data)
                                        raises(DOMException);
  ProcessingInstruction createProcessingInstruction(in DOMString target, 
                                                    in DOMString data)
                                        raises(DOMException);
  Attr               createAttribute(in DOMString name)
                                        raises(DOMException);
  EntityReference    createEntityReference(in DOMString name)
                                        raises(DOMException);
  NodeList           getElementsByTagName(in DOMString tagname);
  // Introduced in DOM Level 2:
  Node               importNode(in Node importedNode, 
                                in boolean deep)
                                        raises(DOMException);
  // Introduced in DOM Level 2:
  Element            createElementNS(in DOMString namespaceURI, 
                                     in DOMString qualifiedName)
                                        raises(DOMException);
  // Introduced in DOM Level 2:
  Attr               createAttributeNS(in DOMString namespaceURI, 
                                       in DOMString qualifiedName)
                                        raises(DOMException);
  // Introduced in DOM Level 2:
  NodeList           getElementsByTagNameNS(in DOMString namespaceURI, 
                                            in DOMString localName);
  // Introduced in DOM Level 2:
  Element            getElementById(in DOMString elementId);
  // Introduced in DOM Level 3:
           attribute DOMString        actualEncoding;
  // Introduced in DOM Level 3:
           attribute DOMString        encoding;
  // Introduced in DOM Level 3:
           attribute boolean          standalone;
  // Introduced in DOM Level 3:
           attribute boolean          strictErrorChecking;
  // Introduced in DOM Level 3:
           attribute DOMString        version;
  // Introduced in DOM Level 3:
  Node               adoptNode(in Node source)
                                        raises(DOMException);
  // Introduced in DOM Level 3:
  void               setBaseURI(in DOMString baseURI)
                                        raises(DOMException);
};

Attributes

actualEncoding of type DOMString, introduced in DOM Level 3: An attribute specifying the actual encoding of this document. This is null otherwise.
doctype of type DocumentType, readonly: The Document Type Declaration (see DocumentType) associated with this document. For HTML documents as well as XML documents without a document type declaration this returns null. The DOM Level 2 does not support editing the Document Type Declaration. docType cannot be altered in any way, including through the use of methods inherited from the Node interface, such as insertNode or removeNode.
documentElement of type Element, readonly: This is a convenience attribute that allows direct access to the child node that is the root element of the document. For HTML documents, this is the element with the tagName "HTML".
encoding of type DOMString, introduced in DOM Level 3: An attribute specifying, as part of the XML declaration, the encoding of this document. This is null when unspecified.
implementation of type DOMImplementation, readonly: The DOMImplementation object that handles this document. A DOM application may use objects from multiple implementations.
standalone of type boolean, introduced in DOM Level 3: An attribute specifying, as part of the XML declaration, whether this document is standalone.
strictErrorChecking of type boolean, introduced in DOM Level 3: An attribute specifying whether errors checking is enforced or not. When set to false, the implementation is free to not test every possible error case normally defined on DOM operations, and not raise any DOMException. In case of error, the behavior is undefined. This attribute is true by defaults.
version of type DOMString, introduced in DOM Level 3: An attribute specifying, as part of the XML declaration, the version number of this document. This is null when unspecified.

Methods

adoptNode introduced in DOM Level 3

Changes the ownerDocument of a node, its children, as well as the attached attribute nodes if there are any. If the node has a parent it is first removed from its parent child list. This effectively allows moving a subtree from one document to another. The following list describes the specifics for each type of node.

ATTRIBUTE_NODE: The ownerElement attribute is set to null and the specified flag is set to true on the adopted Attr. The descendants of the source Attr are recursively adopted.
DOCUMENT_FRAGMENT_NODE: The descendants of the source node are recursively adopted.
DOCUMENT_NODE: Document nodes cannot be adopted.
DOCUMENT_TYPE_NODE: DocumentType nodes cannot be adopted.
ELEMENT_NODE: Specified attribute nodes of the source element are adopted, and the generated Attr nodes. Default attributes are discarded, though if the document being adopted into defines default attributes for this element name, those are assigned. The descendants of the source element are recursively adopted.
ENTITY_NODE: Entity nodes cannot be adopted.
ENTITY_REFERENCE_NODE: Only the EntityReference node itself is adopted, the descendants are discarded, since the source and destination documents might have defined the entity differently. If the document being imported into provides a definition for this entity name, its value is assigned.
NOTATION_NODE: Notation nodes cannot be adopted.
PROCESSING_INSTRUCTION_NODE, TEXT_NODE, CDATA_SECTION_NODE, COMMENT_NODE: These nodes can all be adopted. No specifics.

Issue adoptNode-1:: Should this method simply return null when it fails? How "exceptional" is failure for this method?
Resolution: Stick with raising exceptions only in exceptional circumstances, return null on failure (F2F 19 Jun 2000).
Issue adoptNode-2:: Can an entity node really be adopted?
Resolution: No, neither can Notation nodes (Telcon 13 Dec 2000).
Issue adoptNode-3:: Does this affect keys and hashCode's of the adopted subtree nodes?
If so, what about readonly-ness of key and hashCode?
if not, would appendChild affect keys/hashCodes or would it generate exceptions if key's are duplicate?
Update: Hashcodes have been dropped. Given that the key is only unique within a document an adopted node needs to be given a new key, but what does it mean for the application?

Parameters

source of type Node: The node to move into this document.

Return Value

Node

The adopted node, or null if this operation fails, such as when the source node comes from a different implementation.

Exceptions

DOMException

NOT_SUPPORTED_ERR: Raised if the source node is of type DOCUMENT, DOCUMENT_TYPE.

NO_MODIFICATION_ALLOWED_ERR: Raised when the source node is readonly.

createAttribute

Creates an Attr of the given name. Note that the Attr instance can then be set on an Element using the setAttributeNode method.
To create an attribute with a qualified name and namespace URI, use the createAttributeNS method.

Parameters

name of type DOMString: The name of the attribute.

Return Value

Attr

A new Attr object with the nodeName attribute set to name, and localName, prefix, and namespaceURI set to null. The value of the attribute is the empty string.

Exceptions

DOMException

INVALID_CHARACTER_ERR: Raised if the specified name contains an illegal character.

createAttributeNS introduced in DOM Level 2

Creates an attribute of the given qualified name and namespace URI.

Parameters

namespaceURI of type DOMString: The namespace URI of the attribute to create.
qualifiedName of type DOMString: The qualified name of the attribute to instantiate.

Return Value

Attr

A new Attr object with the following attributes:

Attribute	Value
`Node.nodeName`	qualifiedName
`Node.namespaceURI`	`namespaceURI`
`Node.prefix`	prefix, extracted from `qualifiedName`, or `null` if there is no prefix
`Node.localName`	local name, extracted from `qualifiedName`
`Attr.name`	`qualifiedName`
`Node.nodeValue`	the empty string

Exceptions

DOMException

INVALID_CHARACTER_ERR: Raised if the specified qualified name contains an illegal character, per the XML 1.0 specification [XML].

NAMESPACE_ERR: Raised if the qualifiedName is malformed per the Namespaces in XML specification, if the qualifiedName has a prefix and the namespaceURI is null, if the qualifiedName has a prefix that is "xml" and the namespaceURI is different from "http://www.w3.org/XML/1998/namespace", or if the qualifiedName, or its prefix, is "xmlns" and the namespaceURI is different from "http://www.w3.org/2000/xmlns/".

NOT_SUPPORTED_ERR: Always thrown if the current document does not support the "XML" feature, since namespaces were defined by XML.

createCDATASection

Creates a CDATASection node whose value is the specified string.

Parameters

data of type DOMString: The data for the CDATASection contents.

Return Value

CDATASection

The new CDATASection object.

Exceptions

DOMException

NOT_SUPPORTED_ERR: Raised if this document is an HTML document.

createComment

Creates a Comment node given the specified string.

Parameters

data of type DOMString: The data for the node.

Return Value

Comment

The new Comment object.

No Exceptions

createDocumentFragment

Creates an empty DocumentFragment object.

Return Value

DocumentFragment

A new DocumentFragment.

No Parameters

No Exceptions

createElement

Creates an element of the type specified. Note that the instance returned implements the Element interface, so attributes can be specified directly on the returned object.
In addition, if there are known attributes with default values, Attr nodes representing them are automatically created and attached to the element.
To create an element with a qualified name and namespace URI, use the createElementNS method.

Parameters

tagName of type DOMString: The name of the element type to instantiate. For XML, this is case-sensitive. For HTML, the tagName parameter may be provided in any case, but it must be mapped to the canonical uppercase form by the DOM implementation.

Return Value

Element

A new Element object with the nodeName attribute set to tagName, and localName, prefix, and namespaceURI set to null.

Exceptions

DOMException

INVALID_CHARACTER_ERR: Raised if the specified name contains an illegal character.

createElementNS introduced in DOM Level 2

Creates an element of the given qualified name and namespace URI.

Parameters

namespaceURI of type DOMString: The namespace URI of the element to create.
qualifiedName of type DOMString: The qualified name of the element type to instantiate.

Return Value

Element

A new Element object with the following attributes:

Attribute	Value
`Node.nodeName`	`qualifiedName`
`Node.namespaceURI`	`namespaceURI`
`Node.prefix`	prefix, extracted from `qualifiedName`, or `null` if there is no prefix
`Node.localName`	local name, extracted from `qualifiedName`
`Element.tagName`	`qualifiedName`

Exceptions

DOMException

INVALID_CHARACTER_ERR: Raised if the specified qualified name contains an illegal character, per the XML 1.0 specification [XML].

NAMESPACE_ERR: Raised if the qualifiedName is malformed per the Namespaces in XML specification, if the qualifiedName has a prefix and the namespaceURI is null, or if the qualifiedName has a prefix that is "xml" and the namespaceURI is different from "http://www.w3.org/XML/1998/namespace" [Namespaces].

NOT_SUPPORTED_ERR: Always thrown if the current document does not support the "XML" feature, since namespaces were defined by XML.

createEntityReference

Creates an EntityReference object. In addition, if the referenced entity is known, the child list of the EntityReference node is made the same as that of the corresponding Entity node.

Note: If any descendant of the Entity node has an unbound namespace prefix, the corresponding descendant of the created EntityReference node is also unbound; (its namespaceURI is null). The DOM Level 2 does not support any mechanism to resolve namespace prefixes.

Parameters

name of type DOMString: The name of the entity to reference.

Return Value

EntityReference

The new EntityReference object.

Exceptions

DOMException

INVALID_CHARACTER_ERR: Raised if the specified name contains an illegal character.

NOT_SUPPORTED_ERR: Raised if this document is an HTML document.

createProcessingInstruction

Creates a ProcessingInstruction node given the specified name and data strings.

Parameters

target of type DOMString: The target part of the processing instruction.
data of type DOMString: The data for the node.

Return Value

ProcessingInstruction

The new ProcessingInstruction object.

Exceptions

DOMException

INVALID_CHARACTER_ERR: Raised if the specified target contains an illegal character.

NOT_SUPPORTED_ERR: Raised if this document is an HTML document.

createTextNode

Creates a Text node given the specified string.

Parameters

data of type DOMString: The data for the node.

Return Value

Text

The new Text object.

No Exceptions

getElementById introduced in DOM Level 2

Returns the Element whose ID is given by elementId. If no such element exists, returns null. Behavior is not defined if more than one element has this ID.

Note: The DOM implementation must have information that says which attributes are of type ID. Attributes with the name "ID" are not of type ID unless so defined. Implementations that do not know whether attributes are of type ID or not are expected to return null.

Parameters

elementId of type DOMString: The unique id value for an element.

Return Value

Element

The matching element.

No Exceptions

getElementsByTagName

Returns a NodeList of all the Elements with a given tag name in the order in which they are encountered in a preorder traversal of the Document tree.

Parameters

tagname of type DOMString: The name of the tag to match on. The special value "*" matches all tags.

Return Value

NodeList

A new NodeList object containing all the matched Elements.

No Exceptions

getElementsByTagNameNS introduced in DOM Level 2

Returns a NodeList of all the Elements with a given local name and namespace URI in the order in which they are encountered in a preorder traversal of the Document tree.

Parameters

namespaceURI of type DOMString: The namespace URI of the elements to match on. The special value "*" matches all namespaces.
localName of type DOMString: The local name of the elements to match on. The special value "*" matches all local names.

Return Value

NodeList

A new NodeList object containing all the matched Elements.

No Exceptions

importNode introduced in DOM Level 2

Imports a node from another document to this document. The returned node has no parent; (parentNode is null). The source node is not altered or removed from the original document; this method creates a new copy of the source node.
For all nodes, importing a node creates a node object owned by the importing document, with attribute values identical to the source node's nodeName and nodeType, plus the attributes related to namespaces (prefix, localName, and namespaceURI). As in the cloneNode operation on a Node, the source node is not altered.
Additional information is copied as appropriate to the nodeType, attempting to mirror the behavior expected if a fragment of XML or HTML source was copied from one document to another, recognizing that the two documents may have different DTDs in the XML case. The following list describes the specifics for each type of node.

ATTRIBUTE_NODE: The ownerElement attribute is set to null and the specified flag is set to true on the generated Attr. The descendants of the source Attr are recursively imported and the resulting nodes reassembled to form the corresponding subtree.
Note that the deep parameter has no effect on Attr nodes; they always carry their children with them when imported.
DOCUMENT_FRAGMENT_NODE: If the deep option was set to true, the descendants of the source element are recursively imported and the resulting nodes reassembled to form the corresponding subtree. Otherwise, this simply generates an empty DocumentFragment.
DOCUMENT_NODE: Document nodes cannot be imported.
DOCUMENT_TYPE_NODE: DocumentType nodes cannot be imported.
ELEMENT_NODE: Specified attribute nodes of the source element are imported, and the generated Attr nodes are attached to the generated Element. Default attributes are not copied, though if the document being imported into defines default attributes for this element name, those are assigned. If the importNode deep parameter was set to true, the descendants of the source element are recursively imported and the resulting nodes reassembled to form the corresponding subtree.
ENTITY_NODE: Entity nodes can be imported, however in the current release of the DOM the DocumentType is readonly. Ability to add these imported nodes to a DocumentType will be considered for addition to a future release of the DOM.
On import, the publicId, systemId, and notationName attributes are copied. If a deep import is requested, the descendants of the the source Entity are recursively imported and the resulting nodes reassembled to form the corresponding subtree.
ENTITY_REFERENCE_NODE: Only the EntityReference itself is copied, even if a deep import is requested, since the source and destination documents might have defined the entity differently. If the document being imported into provides a definition for this entity name, its value is assigned.
NOTATION_NODE: Notation nodes can be imported, however in the current release of the DOM the DocumentType is readonly. Ability to add these imported nodes to a DocumentType will be considered for addition to a future release of the DOM.
On import, the publicId and systemId attributes are copied.
Note that the deep parameter has no effect on Notation nodes since they never have any children.
PROCESSING_INSTRUCTION_NODE: The imported node copies its target and data values from those of the source node.
TEXT_NODE, CDATA_SECTION_NODE, COMMENT_NODE: These three types of nodes inheriting from CharacterData copy their data and length attributes from those of the source node.

Parameters

importedNode of type Node: The node to import.
deep of type boolean: If true, recursively import the subtree under the specified node; if false, import only the node itself, as explained above. This has no effect on Attr, EntityReference, and Notation nodes.

Return Value

Node

The imported node that belongs to this Document.

Exceptions

DOMException

NOT_SUPPORTED_ERR: Raised if the type of node being imported is not supported.

setBaseURI introduced in DOM Level 3

Set the baseURI attribute from the Node interface.
If the document is [HTML4.0], [XHTML1.0], or [XHTML1.1], the href attribute of the base will also be changed if any.

Parameters

baseURI of type DOMString: The new absolute URI for this document.

Exceptions

DOMException

SYNTAX_ERR: Raised if baseURI is not an absolute URI per [RFC2396].

No Return Value

Interface Node

The Node interface is the primary datatype for the entire Document Object Model. It represents a single node in the document tree. While all objects implementing the Node interface expose methods for dealing with children, not all objects implementing the Node interface may have children. For example, Text nodes may not have children, and adding children to such nodes results in a DOMException being raised.

The attributes nodeName, nodeValue and attributes are included as a mechanism to get at node information without casting down to the specific derived interface. In cases where there is no obvious mapping of these attributes for a specific nodeType (e.g., nodeValue for an Element or attributes for a Comment), this returns null. Note that the specialized interfaces may contain additional and more convenient mechanisms to get and set the relevant information.

IDL Definition

interface Node {

  // NodeType
  const unsigned short      ELEMENT_NODE                   = 1;
  const unsigned short      ATTRIBUTE_NODE                 = 2;
  const unsigned short      TEXT_NODE                      = 3;
  const unsigned short      CDATA_SECTION_NODE             = 4;
  const unsigned short      ENTITY_REFERENCE_NODE          = 5;
  const unsigned short      ENTITY_NODE                    = 6;
  const unsigned short      PROCESSING_INSTRUCTION_NODE    = 7;
  const unsigned short      COMMENT_NODE                   = 8;
  const unsigned short      DOCUMENT_NODE                  = 9;
  const unsigned short      DOCUMENT_TYPE_NODE             = 10;
  const unsigned short      DOCUMENT_FRAGMENT_NODE         = 11;
  const unsigned short      NOTATION_NODE                  = 12;

  readonly attribute DOMString        nodeName;
           attribute DOMString        nodeValue;
                                        // raises(DOMException) on setting
                                        // raises(DOMException) on retrieval

  readonly attribute unsigned short   nodeType;
  readonly attribute Node             parentNode;
  readonly attribute NodeList         childNodes;
  readonly attribute Node             firstChild;
  readonly attribute Node             lastChild;
  readonly attribute Node             previousSibling;
  readonly attribute Node             nextSibling;
  readonly attribute NamedNodeMap     attributes;
  // Modified in DOM Level 2:
  readonly attribute Document         ownerDocument;
  Node               insertBefore(in Node newChild, 
                                  in Node refChild)
                                        raises(DOMException);
  Node               replaceChild(in Node newChild, 
                                  in Node oldChild)
                                        raises(DOMException);
  Node               removeChild(in Node oldChild)
                                        raises(DOMException);
  Node               appendChild(in Node newChild)
                                        raises(DOMException);
  boolean            hasChildNodes();
  Node               cloneNode(in boolean deep);
  // Modified in DOM Level 2:
  void               normalize();
  // Introduced in DOM Level 2:
  boolean            isSupported(in DOMString feature, 
                                 in DOMString version);
  // Introduced in DOM Level 2:
  readonly attribute DOMString        namespaceURI;
  // Introduced in DOM Level 2:
           attribute DOMString        prefix;
                                        // raises(DOMException) on setting

  // Introduced in DOM Level 2:
  readonly attribute DOMString        localName;
  // Introduced in DOM Level 2:
  boolean            hasAttributes();
  // Introduced in DOM Level 3:
  readonly attribute DOMString        baseURI;
  enum DocumentOrder {
    DOCUMENT_ORDER_PRECEDING,
    DOCUMENT_ORDER_FOLLOWING,
    DOCUMENT_ORDER_SAME,
    DOCUMENT_ORDER_UNORDERED
  };
  // Introduced in DOM Level 3:
  DocumentOrder      compareDocumentOrder(in Node other)
                                        raises(DOMException);
  enum TreePosition {
    TREE_POSITION_PRECEDING,
    TREE_POSITION_FOLLOWING,
    TREE_POSITION_ANCESTOR,
    TREE_POSITION_DESCENDANT,
    TREE_POSITION_SAME,
    TREE_POSITION_UNORDERED
  };
  // Introduced in DOM Level 3:
  TreePosition       compareTreePosition(in Node other)
                                        raises(DOMException);
  // Introduced in DOM Level 3:
           attribute DOMString        textContent;
  // Introduced in DOM Level 3:
  boolean            isSameNode(in Node other);
  // Introduced in DOM Level 3:
  DOMString          lookupNamespacePrefix(in DOMString namespaceURI);
  // Introduced in DOM Level 3:
  DOMString          lookupNamespaceURI(in DOMString prefix);
  // Introduced in DOM Level 3:
  void               normalizeNS();
  // Introduced in DOM Level 3:
  readonly attribute DOMKey           key;
  // Introduced in DOM Level 3:
  boolean            equalsNode(in Node arg, 
                                in boolean deep);
  // Introduced in DOM Level 3:
  Node               getAs(in DOMString feature);
};

Definition group NodeType

An integer indicating which type of node this is.

Note: Numeric codes up to 200 are reserved to W3C for possible future use.

Defined Constants

ATTRIBUTE_NODE: The node is an Attr.
CDATA_SECTION_NODE: The node is a CDATASection.
COMMENT_NODE: The node is a Comment.
DOCUMENT_FRAGMENT_NODE: The node is a DocumentFragment.
DOCUMENT_NODE: The node is a Document.
DOCUMENT_TYPE_NODE: The node is a DocumentType.
ELEMENT_NODE: The node is an Element.
ENTITY_NODE: The node is an Entity.
ENTITY_REFERENCE_NODE: The node is an EntityReference.
NOTATION_NODE: The node is a Notation.
PROCESSING_INSTRUCTION_NODE: The node is a ProcessingInstruction.
TEXT_NODE: The node is a Text node.

The values of nodeName, nodeValue, and attributes vary according to the node type as follows:

Interface	nodeName	nodeValue	attributes
Attr	name of attribute	value of attribute	null
CDATASection	`"#cdata-section"`	content of the CDATA Section	null
Comment	`"#comment"`	content of the comment	null
Document	`"#document"`	null	null
DocumentFragment	`"#document-fragment"`	null	null
DocumentType	document type name	null	null
Element	tag name	null	NamedNodeMap
Entity	entity name	null	null
EntityReference	name of entity referenced	null	null
Notation	notation name	null	null
ProcessingInstruction	target	entire content excluding the target	null
Text	`"#text"`	content of the text node	null

Type Definition DocumentOrder

A type to hold the document order of a node relative to another node.

Enumeration _DocumentOrder

An enumeration of the different orders the node can be in.

Enumerator Values

DOCUMENT_ORDER_PRECEDING	The node preceds the reference node in document order.
DOCUMENT_ORDER_FOLLOWING	The node follows the reference node in document order.
DOCUMENT_ORDER_SAME	The two nodes have the same document order.
DOCUMENT_ORDER_UNORDERED	The two nodes are unordered, they do not have any common ancestor.

Type Definition TreePosition

A type to hold the relative tree position of a node with respect to another node.

Enumeration _TreePosition: An enumeration of the different o

Document Object Model (DOM) Level 3 Core Specification

Version 1.0

W3C Working Draft 05 June 2001

Abstract

Status of this document

Table of contents

Expanded Table of Contents

Copyright Notice

W3C Document Copyright Notice and License

W3C Software Copyright Notice and License

1. Document Object Model Core

Table of contents

1.1. Overview of the DOM Core Interfaces

1.1.1. The DOM Structure Model

1.1.2. Memory Management

1.1.3. Naming Conventions

1.1.4. Inheritance vs. Flattened Views of the API

1.1.5. The `DOMString` type

1.1.6. The `DOMTimeStamp` type

1.1.7. The `DOMKey` type

1.1.8. String comparisons in the DOM

1.1.9. XML Namespaces

1.1.10. Mutiple XML Datatypes in a DOM Document

1.2. Fundamental Interfaces

Document Object Model (DOM) Level 3 Core Specification

Version 1.0

W3C Working Draft 05 June 2001

Abstract

Status of this document

Table of contents

Expanded Table of Contents

Copyright Notice

W3C Document Copyright Notice and License

W3C Software Copyright Notice and License

1. Document Object Model Core

Table of contents

1.1. Overview of the DOM Core Interfaces

1.1.1. The DOM Structure Model

1.1.2. Memory Management

1.1.3. Naming Conventions

1.1.4. Inheritance vs. Flattened Views of the API

1.1.5. The DOMString type

1.1.6. The DOMTimeStamp type

1.1.7. The DOMKey type

1.1.8. String comparisons in the DOM

1.1.9. XML Namespaces

1.1.10. Mutiple XML Datatypes in a DOM Document

1.2. Fundamental Interfaces

1.1.5. The `DOMString` type

1.1.6. The `DOMTimeStamp` type

1.1.7. The `DOMKey` type