Document Object Model Core (original) (raw)

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 aDocument 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 childnodes 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 NamedNodeMapinterface to handle unordered sets of nodes referenced by their name attribute, such as the attributes of an Element. NodeList and NamedNodeMapobjects in the DOM are live; that is, changes to the underlying document structure are reflected in all relevant NodeList and NamedNodeMapobjects. 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 NamedNodeMapobjects.

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

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 DOM Level 2 API does not define a standard way to create DOMImplementationobjects; DOM implementations must provide some proprietary way of bootstrapping these DOM interfaces, and then all other objects can be built from there.

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 ECMAScriptand 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 APIspresent 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 theNode 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 inheritancehierarchy 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 Nodeinterface, we don't specify a completely redundant one.) Thus, even though there is a generic nodeName attribute on the Nodeinterface, there is still a tagName attribute on theElementinterface; 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;

• 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 DOMTimeStamptype

To ensure interoperability, the DOM specifies the following:

• Type Definition DOMTimeStamp
  A DOMTimeStamprepresents 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. 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].

1.1.8. XML Namespaces

The DOM Level 2 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 tonamespace URIsas 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 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 nameis "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 Documentinterface 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 andcreateAttributeNS 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 andcreateAttribute. 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, usingsetAttributeNS, an element may have two attributes (or more) that have the same nodeName, but different namespaceURIs. CallinggetAttribute 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 differentnodeNames but the same prefix andnamespaceURI. In this casegetAttributeNodeNS 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 itsnodeName 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 andsetAttributeNS affect the node thatgetAttribute and getAttributeNS, respectively, return.

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 2 HTML], unless otherwise specified.

A DOM application may use the hasFeature(feature, version) method of the DOMImplementationinterface with parameter values "Core" and "2.0" (respectively) to determine whether or not this module is supported by the implementation. Any implementation that conforms to DOM Level 2 or a DOM Level 2 module must conform to the Core module. Please refer to additional information about conformance in this specification.

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 inDOM 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); };

Methods

createDocumentintroduced in DOM Level 2

Creates an XML Document object of the specified type with its document element. HTML-only DOM implementations do not need to implement this method.

Exceptions

createDocumentTypeintroduced 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.
HTML-only DOM implementations do not need to implement this method.

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.

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 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 by reversing the name of the Internet domain name of the person (or the organization that the person belongs to) who defines the feature, component by component, and using this as a prefix. For instance, the W3C SVG Working Group defines the feature "org.w3c.dom.svg".

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

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 takeDocumentFragment 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 DocumentFragmentmight 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 Nodethat may take children) the children of theDocumentFragment and not theDocumentFragment itself are inserted into the Node. This makes the DocumentFragment very useful when the user wishes to create nodes that are siblings; theDocumentFragment acts as the parent of these nodes so that the user can use the standard methods from the Nodeinterface, such as insertBefore andappendChild.

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); };

Attributes

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 returnsnull. 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 theNode interface, such as insertNode or removeNode.

documentElement of type Element, readonly

This is a convenienceattribute 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".

implementation of type DOMImplementation, readonly

The DOMImplementationobject that handles this document. A DOM application may use objects from multiple implementations.

Methods

createAttribute

Creates an Attr of the given name. Note that the Attr instance can then be set on an Element using thesetAttributeNode 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

Exceptions

createAttributeNS introduced in DOM Level 2

Creates an attribute of the given qualified name and namespace URI. HTML-only DOM implementations do not need to implement this method.

Exceptions

createCDATASection

Creates a CDATASection node whose value is the specified string.

Exceptions

createComment

Creates a Comment node given the specified string.

Parameters

data of type DOMString

The data for the node.

No Exceptions

createDocumentFragment

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

Exceptions

createElementNS introduced in DOM Level 2

Creates an element of the given qualified name and namespace URI. HTML-only DOM implementations do not need to implement this method.

Exceptions

createEntityReference

Creates an EntityReferenceobject. 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 isnull). 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.

Exceptions

createProcessingInstruction

Creates a ProcessingInstructionnode 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.

Exceptions

createTextNode

Creates a Text node given the specified string.

Parameters

data of type DOMString

The data for the node.

No Exceptions

getElementById introduced in DOM Level 2

Returns the Element whoseID 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.

No Exceptions

getElementsByTagName

Returns a NodeList of all theElements 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.

No Exceptions

getElementsByTagNameNS introduced in DOM Level 2

Returns a NodeList of all theElements with a given local nameand 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.

No Exceptions

importNode introduced inDOM Level 2

Imports a node from another document to this document. The returned node has no parent; (parentNodeis 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 thecloneNode operation on a Node, the source node is not altered.
Additional information is copied as appropriate to thenodeType, 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 tonull and the specified flag is set totrue 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 descendantsof 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

DocumentTypenodes 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, andnotationName attributes are copied. If adeep import is requested, the descendants of the the source Entityare recursively imported and the resulting nodes reassembled to form the corresponding subtree.

ENTITY_REFERENCE_NODE

Only the EntityReferenceitself 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 systemIdattributes 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 anddata 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 typeboolean

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, andNotationnodes.

Return Value

Exceptions

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 Nodeinterface expose methods for dealing with children, not all objects implementing the Node interface may have children. For example, Textnodes may not have children, and adding children to such nodes results in a DOMException being raised.

The attributes nodeName, nodeValue andattributes 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 orattributes 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(); };

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, andattributes vary according to the node type as follows:

Attributes

attributes of type NamedNodeMap, readonly

A NamedNodeMapcontaining the attributes of this node (if it is an Element) ornull otherwise.

childNodes of type NodeList, readonly

A NodeListthat contains all children of this node. If there are no children, this is a NodeList containing no nodes.

firstChild of type Node, readonly

The first child of this node. If there is no such node, this returns null.

lastChild of type Node, readonly

The last child of this node. If there is no such node, this returns null.

localName of type DOMString, readonly, introduced in DOM Level 2

Returns the local part of the qualified nameof this node.
For nodes of any type other than ELEMENT_NODE andATTRIBUTE_NODE and nodes created with a DOM Level 1 method, such as createElement from the Document interface, this is always null.

namespaceURI of type DOMString, readonly, introduced in DOM Level 2

The namespace URI of this node, or null if it is unspecified.
This is not a computed value that is the result of a namespace lookup based on an examination of the namespace declarations in scope. It is merely the namespace URI given at creation time.
For nodes of any type other than ELEMENT_NODE andATTRIBUTE_NODE and nodes created with a DOM Level 1 method, such as createElement from the Document interface, this is always null.

Note: Per the Namespaces in XML Specification [Namespaces] an attribute does not inherit its namespace from the element it is attached to. If an attribute is not explicitly given a namespace, it simply has no namespace.

nextSibling of type Node, readonly

The node immediately following this node. If there is no such node, this returns null.

nodeName of type DOMString, readonly

The name of this node, depending on its type; see the table above.

nodeType of type unsigned short, readonly

A code representing the type of the underlying object, as defined above.

nodeValue of type DOMString

The value of this node, depending on its type; see the table above. When it is defined to be null, setting it has no effect.

Exceptions on setting

Exceptions on retrieval

ownerDocument of type Document, readonly, modified in DOM Level 2

The Documentobject associated with this node. This is also the Document object used to create new nodes. When this node is a Document or a DocumentType which is not used with any Document yet, this isnull.

parentNode of type Node, readonly

The parent of this node. All nodes, except Attr, Document, DocumentFragment, Entity, and Notation may have a parent. However, if a node has just been created and not yet added to the tree, or if it has been removed from the tree, this isnull.

prefix of type DOMString, introduced in DOM Level 2

The namespace prefix of this node, or null if it is unspecified.
Note that setting this attribute, when permitted, changes thenodeName attribute, which holds the qualified name, as well as the tagName and nameattributes of the Element and Attr interfaces, when applicable.
Note also that changing the prefix of an attribute that is known to have a default value, does not make a new attribute with the default value and the original prefix appear, since thenamespaceURI and localName do not change.
For nodes of any type other than ELEMENT_NODE andATTRIBUTE_NODE and nodes created with a DOM Level 1 method, such as createElement from the Document interface, this is always null.

Exceptions on setting

previousSibling of type Node, readonly

The node immediately preceding this node. If there is no such node, this returns null.

Methods

appendChild

Adds the node newChild to the end of the list of children of this node. If the newChildis already in the tree, it is first removed.

Parameters

newChild of type Node

The node to add.
If it is a DocumentFragmentobject, the entire contents of the document fragment are moved into the child list of this node

Exceptions

cloneNode

Returns a duplicate of this node, i.e., serves as a generic copy constructor for nodes. The duplicate node has no parent; (parentNode is null.).
Cloning an Element copies all attributes and their values, including those generated by the XML processor to represent defaulted attributes, but this method does not copy any text it contains unless it is a deep clone, since the text is contained in a child Text node. Cloning an Attribute directly, as opposed to be cloned as part of an Element cloning operation, returns a specified attribute (specified istrue). Cloning any other type of node simply returns a copy of this node.
Note that cloning an immutable subtree results in a mutable copy, but the children of an EntityReference clone are readonly. In addition, clones of unspecified Attr nodes are specified. And, cloning Document, DocumentType, Entity, and Notation nodes is implementation dependent.

Parameters

deep of typeboolean

If true, recursively clone the subtree under the specified node; if false, clone only the node itself (and its attributes, if it is an Element).

No Exceptions

hasAttributes introduced in DOM Level 2

Returns whether this node (if it is an element) has any attributes.

Return Value

No Parameters

No Exceptions

hasChildNodes

Returns whether this node has any children.

Return Value

No Parameters

No Exceptions

insertBefore

Inserts the node newChild before the existing child node refChild. IfrefChild is null, insertnewChild at the end of the list of children.
If newChild is a DocumentFragmentobject, all of its children are inserted, in the same order, beforerefChild. If the newChild is already in the tree, it is first removed.

Parameters

newChild of type Node

The node to insert.

refChild of type Node

The reference node, i.e., the node before which the new node must be inserted.

Return Value

Exceptions

isSupported introduced in DOM Level 2

Tests whether the DOM implementation implements a specific feature and that feature is supported by this node.

Parameters

feature of type DOMString

The name of the feature to test. This is the same name which can be passed to the method hasFeature on DOMImplementation.

version of type DOMString

This is the version number of the feature to test. In Level 2, version 1, this is the string "2.0". If the version is not specified, supporting any version of the feature will cause the method to return true.

Return Value

No Exceptions

normalize modified in DOM Level 2

Puts all Text nodes in the full depth of the sub-tree underneath this Node, including attribute nodes, into a "normal" form where only structure (e.g., elements, comments, processing instructions, CDATA sections, and entity references) separates Text nodes, i.e., there are neither adjacent Text nodes nor empty Text nodes. This can be used to ensure that the DOM view of a document is the same as if it were saved and re-loaded, and is useful when operations (such as XPointer [XPointer] lookups) that depend on a particular document tree structure are to be used.

Note: In cases where the document contains CDATASections, the normalize operation alone may not be sufficient, since XPointers do not differentiate between Text nodes and CDATASectionnodes.

No Parameters

No Return Value

No Exceptions

removeChild

Removes the child node indicated byoldChild from the list of children, and returns it.

Parameters

oldChild of type Node

The node being removed.

Exceptions

replaceChild

Replaces the child node oldChildwith newChild in the list of children, and returns theoldChild node.
If newChild is a DocumentFragmentobject, oldChild is replaced by all of the DocumentFragmentchildren, which are inserted in the same order. If thenewChild is already in the tree, it is first removed.

Parameters

newChild of type Node

The new node to put in the child list.

oldChild of type Node

The node being replaced in the list.

Exceptions

Interface NodeList

The NodeList interface provides the abstraction of an ordered collection of nodes, without defining or constraining how this collection is implemented. NodeList objects in the DOM are live.

The items in the NodeList are accessible via an integral index, starting from 0.

IDL Definition

interface NodeList { Node item(in unsigned long index); readonly attribute unsigned long length; };

Attributes

length of type unsigned long, readonly

The number of nodes in the list. The range of valid child node indices is 0 to length-1 inclusive.

Methods

item

Returns the indexth item in the collection. If index is greater than or equal to the number of nodes in the list, this returns null.

Parameters

index of typeunsigned long

Index into the collection.

Return Value

No Exceptions

Interface NamedNodeMap

Objects implementing the NamedNodeMap interface are used to represent collections of nodes that can be accessed by name. Note that NamedNodeMap does not inherit from NodeList;NamedNodeMaps are not maintained in any particular order. Objects contained in an object implementingNamedNodeMap may also be accessed by an ordinal index, but this is simply to allow convenient enumeration of the contents of a NamedNodeMap, and does not imply that the DOM specifies an order to these Nodes.

NamedNodeMap objects in the DOM are live.

IDL Definition

interface NamedNodeMap { Node getNamedItem(in DOMString name); Node setNamedItem(in Node arg) raises(DOMException); Node removeNamedItem(in DOMString name) raises(DOMException); Node item(in unsigned long index); readonly attribute unsigned long length; // Introduced in DOM Level 2: Node getNamedItemNS(in DOMString namespaceURI, in DOMString localName); // Introduced in DOM Level 2: Node setNamedItemNS(in Node arg) raises(DOMException); // Introduced in DOM Level 2: Node removeNamedItemNS(in DOMString namespaceURI, in DOMString localName) raises(DOMException); };

Attributes

length of type unsigned long, readonly

The number of nodes in this map. The range of valid child node indices is 0 to length-1 inclusive.

Methods

getNamedItem

Retrieves a node specified by name.

Parameters

name of type DOMString

The nodeName of a node to retrieve.

Return Value

No Exceptions

getNamedItemNS introduced in DOM Level 2

Retrieves a node specified by local name and namespace URI. HTML-only DOM implementations do not need to implement this method.

Return Value

No Exceptions

item

Returns the indexth item in the map. If index is greater than or equal to the number of nodes in this map, this returns null.

Parameters

index of typeunsigned long

Index into this map.

Return Value

No Exceptions

removeNamedItem

Removes a node specified by name. When this map contains the attributes attached to an element, if the removed attribute is known to have a default value, an attribute immediately appears containing the default value as well as the corresponding namespace URI, local name, and prefix when applicable.

Parameters

name of type DOMString

The nodeName of the node to remove.

Return Value

Exceptions

removeNamedItemNS introduced in DOM Level 2

Removes a node specified by local name and namespace URI. A removed attribute may be known to have a default value when this map contains the attributes attached to an element, as returned by the attributes attribute of the Node interface. If so, an attribute immediately appears containing the default value as well as the corresponding namespace URI, local name, and prefix when applicable.
HTML-only DOM implementations do not need to implement this method.

Return Value

Exceptions

setNamedItem

Adds a node using its nodeNameattribute. If a node with that name is already present in this map, it is replaced by the new one.
As the nodeName attribute is used to derive the name which the node must be stored under, multiple nodes of certain types (those that have a "special" string value) cannot be stored as the names would clash. This is seen as preferable to allowing nodes to be aliased.

Parameters

arg of type Node

A node to store in this map. The node will later be accessible using the value of its nodeName attribute.

Return Value

Exceptions

setNamedItemNS introduced in DOM Level 2

Adds a node using its namespaceURIand localName. If a node with that namespace URI and that local name is already present in this map, it is replaced by the new one.
HTML-only DOM implementations do not need to implement this method.

Parameters

arg of type Node

A node to store in this map. The node will later be accessible using the value of its namespaceURI andlocalName attributes.

Return Value

Exceptions

Interface CharacterData

The CharacterData interface extends Node with a set of attributes and methods for accessing character data in the DOM. For clarity this set is defined here rather than on each object that uses these attributes and methods. No DOM objects correspond directly to CharacterData, though Text and others do inherit the interface from it. All offsets in this interface start from 0.

As explained in the DOMString interface, text strings in the DOM are represented in UTF-16, i.e. as a sequence of 16-bit units. In the following, the term 16-bit units is used whenever necessary to indicate that indexing on CharacterData is done in 16-bit units.

IDL Definition

interface CharacterData : Node { attribute DOMString data; // raises(DOMException) on setting // raises(DOMException) on retrieval

readonly attribute unsigned long length; DOMString substringData(in unsigned long offset, in unsigned long count) raises(DOMException); void appendData(in DOMString arg) raises(DOMException); void insertData(in unsigned long offset, in DOMString arg) raises(DOMException); void deleteData(in unsigned long offset, in unsigned long count) raises(DOMException); void replaceData(in unsigned long offset, in unsigned long count, in DOMString arg) raises(DOMException); };

Attributes

data of type DOMString

The character data of the node that implements this interface. The DOM implementation may not put arbitrary limits on the amount of data that may be stored in a CharacterData node. However, implementation limits may mean that the entirety of a node's data may not fit into a single DOMString. In such cases, the user may call substringData to retrieve the data in appropriately sized pieces.

Exceptions on setting

Exceptions on retrieval

length of type unsigned long, readonly

The number of 16-bit units that are available through data and thesubstringData method below. This may have the value zero, i.e., CharacterData nodes may be empty.

Methods

appendData

Append the string to the end of the character data of the node. Upon success, data provides access to the concatenation of data and the DOMString specified.

Exceptions

No Return Value

deleteData

Remove a range of 16-bit units from the node. Upon success, data and lengthreflect the change.

Parameters

offset of typeunsigned long

The offset from which to start removing.

count of typeunsigned long

The number of 16-bit units to delete. If the sum ofoffset and count exceedslength then all 16-bit units from offsetto the end of the data are deleted.

Exceptions

No Return Value

insertData

Insert a string at the specified 16-bit unitoffset.

Parameters

offset of typeunsigned long

The character offset at which to insert.

arg of type DOMString

The DOMString to insert.

Exceptions

No Return Value

replaceData

Replace the characters starting at the specified 16-bit unit offset with the specified string.

Parameters

offset of typeunsigned long

The offset from which to start replacing.

count of typeunsigned long

The number of 16-bit units to replace. If the sum ofoffset and count exceedslength, then all 16-bit units to the end of the data are replaced; (i.e., the effect is the same as aremove method call with the same range, followed by anappend method invocation).

arg of type DOMString

The DOMString with which the range must be replaced.

Exceptions

No Return Value

substringData

Extracts a range of data from the node.

Parameters

offset of typeunsigned long

Start offset of substring to extract.

count of typeunsigned long

The number of 16-bit units to extract.

Return Value

Exceptions

Interface Attr

The Attr interface represents an attribute in an Element object. Typically the allowable values for the attribute are defined in a document type definition.

Attr objects inherit the Node interface, but since they are not actually child nodes of the element they describe, the DOM does not consider them part of the document tree. Thus, the Node attributesparentNode, previousSibling, andnextSibling have a null value forAttr objects. The DOM takes the view that attributes are properties of elements rather than having a separate identity from the elements they are associated with; this should make it more efficient to implement such features as default attributes associated with all elements of a given type. Furthermore,Attr nodes may not be immediate children of a DocumentFragment. However, they can be associated with Element nodes contained within a DocumentFragment. In short, users and implementors of the DOM need to be aware thatAttr nodes have some things in common with other objects inheriting the Node interface, but they also are quite distinct.

The attribute's effective value is determined as follows: if this attribute has been explicitly assigned any value, that value is the attribute's effective value; otherwise, if there is a declaration for this attribute, and that declaration includes a default value, then that default value is the attribute's effective value; otherwise, the attribute does not exist on this element in the structure model until it has been explicitly added. Note that the nodeValue attribute on the Attrinstance can also be used to retrieve the string version of the attribute's value(s).

In XML, where the value of an attribute can contain entity references, the child nodes of the Attr node may be either Text orEntityReferencenodes (when these are in use; see the description of EntityReference for discussion). Because the DOM Core is not aware of attribute types, it treats all attribute values as simple strings, even if the DTD or schema declares them as having tokenized types.

IDL Definition

interface Attr : Node { readonly attribute DOMString name; readonly attribute boolean specified; attribute DOMString value; // raises(DOMException) on setting

// Introduced in DOM Level 2: readonly attribute Element ownerElement; };

Attributes

name of type DOMString, readonly

Returns the name of this attribute.

ownerElement of type Element, readonly, introduced in DOM Level 2

The Elementnode this attribute is attached to or null if this attribute is not in use.

specified of typeboolean, readonly

If this attribute was explicitly given a value in the original document, this is true; otherwise, it isfalse. Note that the implementation is in charge of this attribute, not the user. If the user changes the value of the attribute (even if it ends up having the same value as the default value) then the specified flag is automatically flipped to true. To re-specify the attribute as the default value from the DTD, the user must delete the attribute. The implementation will then make a new attribute available withspecified set to false and the default value (if one exists).
In summary:

• If the attribute has an assigned value in the document thenspecified is true, and the value is the assigned value.
• If the attribute has no assigned value in the document and has a default value in the DTD, then specified isfalse, and the value is the default value in the DTD.
• If the attribute has no assigned value in the document and has a value of #IMPLIED in the DTD, then the attribute does not appear in the structure model of the document.
• If the ownerElement attribute is null(i.e. because it was just created or was set to nullby the various removal and cloning operations)specified is true.

value of type DOMString

On retrieval, the value of the attribute is returned as a string. Character and general entity references are replaced with their values. See also the method getAttribute on theElementinterface.
On setting, this creates a Text node with the unparsed contents of the string. I.e. any characters that an XML processor would recognize as markup are instead treated as literal text. See also the method setAttribute on the Elementinterface.

Exceptions on setting

Interface Element

The Element interface represents an element in an HTML or XML document. Elements may have attributes associated with them; since the Element interface inherits from Node, the genericNode interface attribute attributes may be used to retrieve the set of all attributes for an element. There are methods on theElement interface to retrieve either an Attr object by name or an attribute value by name. In XML, where an attribute value may contain entity references, an Attr object should be retrieved to examine the possibly fairly complex sub-tree representing the attribute value. On the other hand, in HTML, where all attributes have simple string values, methods to directly access an attribute value can safely be used as a convenience.

Note: In DOM Level 2, the method normalizeis inherited from the Node interface where it was moved.

IDL Definition

interface Element : Node { readonly attribute DOMString tagName; DOMString getAttribute(in DOMString name); void setAttribute(in DOMString name, in DOMString value) raises(DOMException); void removeAttribute(in DOMString name) raises(DOMException); Attr getAttributeNode(in DOMString name); Attr setAttributeNode(in Attr newAttr) raises(DOMException); Attr removeAttributeNode(in Attr oldAttr) raises(DOMException); NodeList getElementsByTagName(in DOMString name); // Introduced in DOM Level 2: DOMString getAttributeNS(in DOMString namespaceURI, in DOMString localName); // Introduced in DOM Level 2: void setAttributeNS(in DOMString namespaceURI, in DOMString qualifiedName, in DOMString value) raises(DOMException); // Introduced in DOM Level 2: void removeAttributeNS(in DOMString namespaceURI, in DOMString localName) raises(DOMException); // Introduced in DOM Level 2: Attr getAttributeNodeNS(in DOMString namespaceURI, in DOMString localName); // Introduced in DOM Level 2: Attr setAttributeNodeNS(in Attr newAttr) raises(DOMException); // Introduced in DOM Level 2: NodeList getElementsByTagNameNS(in DOMString namespaceURI, in DOMString localName); // Introduced in DOM Level 2: boolean hasAttribute(in DOMString name); // Introduced in DOM Level 2: boolean hasAttributeNS(in DOMString namespaceURI, in DOMString localName); };

Attributes

tagName of type DOMString, readonly

The name of the element. For example, in:

tagName has the value "elementExample". Note that this is case-preserving in XML, as are all of the operations of the DOM. The HTML DOM returns thetagName of an HTML element in the canonical uppercase form, regardless of the case in the source HTML document.

Methods

getAttribute

Retrieves an attribute value by name.

Parameters

name of type DOMString

The name of the attribute to retrieve.

Return Value

No Exceptions

getAttributeNS introduced in DOM Level 2

Retrieves an attribute value by local name and namespace URI. HTML-only DOM implementations do not need to implement this method.

Return Value

No Exceptions

getAttributeNode

Retrieves an attribute node by name.
To retrieve an attribute node by qualified name and namespace URI, use the getAttributeNodeNS method.

Parameters

name of type DOMString

The name (nodeName) of the attribute to retrieve.

Return Value

No Exceptions

getAttributeNodeNS introduced inDOM Level 2

Retrieves an Attr node by local name and namespace URI. HTML-only DOM implementations do not need to implement this method.

Return Value

No Exceptions

getElementsByTagName

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

Parameters

name of type DOMString

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

Return Value

No Exceptions

getElementsByTagNameNS introduced inDOM Level 2

Returns a NodeList of all thedescendant Elements with a given local name and namespace URI in the order in which they are encountered in a preorder traversal of this Element tree.
HTML-only DOM implementations do not need to implement this method.

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.

No Exceptions

hasAttribute introduced in DOM Level 2

Returns true when an attribute with a given name is specified on this element or has a default value, false otherwise.

Parameters

name of type DOMString

The name of the attribute to look for.

Return Value

No Exceptions

hasAttributeNS introduced in DOM Level 2

Returns true when an attribute with a given local name and namespace URI is specified on this element or has a default value, false otherwise. HTML-only DOM implementations do not need to implement this method.

Return Value

No Exceptions

removeAttribute

Removes an attribute by name. If the removed attribute is known to have a default value, an attribute immediately appears containing the default value as well as the corresponding namespace URI, local name, and prefix when applicable.
To remove an attribute by local name and namespace URI, use theremoveAttributeNS method.

Parameters

name of type DOMString

The name of the attribute to remove.

Exceptions

No Return Value

removeAttributeNS introduced in DOM Level 2

Removes an attribute by local name and namespace URI. If the removed attribute has a default value it is immediately replaced. The replacing attribute has the same namespace URI and local name, as well as the original prefix.
HTML-only DOM implementations do not need to implement this method.

Exceptions

No Return Value

removeAttributeNode

Removes the specified attribute node. If the removed Attr has a default value it is immediately replaced. The replacing attribute has the same namespace URI and local name, as well as the original prefix, when applicable.

Parameters

oldAttr of type Attr

The Attr node to remove from the attribute list.

Exceptions

setAttribute

Adds a new attribute. If an attribute with that name is already present in the element, its value is changed to be that of the value parameter. This value is a simple string; it is not parsed as it is being set. So any markup (such as syntax to be recognized as an entity reference) is treated as literal text, and needs to be appropriately escaped by the implementation when it is written out. In order to assign an attribute value that contains entity references, the user must create an Attr node plus anyText and EntityReferencenodes, build the appropriate subtree, and usesetAttributeNode to assign it as the value of an attribute.
To set an attribute with a qualified name and namespace URI, use the setAttributeNS method.

Parameters

name of type DOMString

The name of the attribute to create or alter.

value of type DOMString

Value to set in string form.

Exceptions

No Return Value

setAttributeNS introduced in DOM Level 2

Adds a new attribute. If an attribute with the same local name and namespace URI is already present on the element, its prefix is changed to be the prefix part of thequalifiedName, and its value is changed to be thevalue parameter. This value is a simple string; it is not parsed as it is being set. So any markup (such as syntax to be recognized as an entity reference) is treated as literal text, and needs to be appropriately escaped by the implementation when it is written out. In order to assign an attribute value that contains entity references, the user must create an Attr node plus anyText and EntityReferencenodes, build the appropriate subtree, and usesetAttributeNodeNS or setAttributeNode to assign it as the value of an attribute.
HTML-only DOM implementations do not need to implement this method.

Exceptions

No Return Value

setAttributeNode

Adds a new attribute node. If an attribute with that name (nodeName) is already present in the element, it is replaced by the new one.
To add a new attribute node with a qualified name and namespace URI, use the setAttributeNodeNS method.

Parameters

newAttr of type Attr

The Attr node to add to the attribute list.

Return Value

Exceptions

setAttributeNodeNS introduced inDOM Level 2

Adds a new attribute. If an attribute with that local name and that namespace URI is already present in the element, it is replaced by the new one.
HTML-only DOM implementations do not need to implement this method.

Parameters

newAttr of type Attr

The Attr node to add to the attribute list.

Return Value

Exceptions

Interface Text

The Text interface inherits from CharacterData and represents the textual content (termed character data in XML) of an Element or Attr. If there is no markup inside an element's content, the text is contained in a single object implementing the Text interface that is the only child of the element. If there is markup, it is parsed into the information items (elements, comments, etc.) and Textnodes that form the list of children of the element.

When a document is first made available via the DOM, there is only one Text node for each block of text. Users may create adjacent Text nodes that represent the contents of a given element without any intervening markup, but should be aware that there is no way to represent the separations between these nodes in XML or HTML, so they will not (in general) persist between DOM editing sessions. The normalize() method on Node merges any such adjacent Text objects into a single node for each block of text.

IDL Definition

interface Text : CharacterData { Text splitText(in unsigned long offset) raises(DOMException); };

Methods

splitText

Breaks this node into two nodes at the specified offset, keeping both in the tree as siblings. After being split, this node will contain all the content up to theoffset point. A new node of the same type, which contains all the content at and after the offsetpoint, is returned. If the original node had a parent node, the new node is inserted as the next sibling of the original node. When the offset is equal to the length of this node, the new node has no data.

Parameters

offset of typeunsigned long

The 16-bit unit offset at which to split, starting from0.

Return Value

Exceptions

Interface Comment

This interface inherits from CharacterData and represents the content of a comment, i.e., all the characters between the starting '<!--' and ending '-->'. Note that this is the definition of a comment in XML, and, in practice, HTML, although some HTML tools may implement the full SGML comment structure.

IDL Definition

interface Comment : CharacterData { };

1.3. Extended Interfaces

The interfaces defined here form part of the DOM Core specification, but objects that expose these interfaces will never be encountered in a DOM implementation that deals only with HTML. As such, HTML-only DOM implementations [DOM Level 2 HTML] do not need to have objects that implement these interfaces.

The interfaces found within this section are not mandatory. A DOM application may use the hasFeature(feature, version) method of the DOMImplementationinterface with parameter values "XML" and "2.0" (respectively) to determine whether or not this module is supported by the implementation. In order to fully support this module, an implementation must also support the "Core" feature defined in Fundamental Interfaces. Please refer to additional information about Conformance in this specification.

Interface CDATASection

CDATA sections are used to escape blocks of text containing characters that would otherwise be regarded as markup. The only delimiter that is recognized in a CDATA section is the "]]>" string that ends the CDATA section. CDATA sections cannot be nested. Their primary purpose is for including material such as XML fragments, without needing to escape all the delimiters.

The DOMStringattribute of the Text node holds the text that is contained by the CDATA section. Note that this_may_ contain characters that need to be escaped outside of CDATA sections and that, depending on the character encoding ("charset") chosen for serialization, it may be impossible to write out some characters as part of a CDATA section.

The CDATASection interface inherits from the CharacterDatainterface through the Text interface. Adjacent CDATASection nodes are not merged by use of the normalize method of the Node interface.

Note: Because no markup is recognized within aCDATASection, character numeric references cannot be used as an escape mechanism when serializing. Therefore, action needs to be taken when serializing a CDATASection with a character encoding where some of the contained characters cannot be represented. Failure to do so would not produce well-formed XML.
One potential solution in the serialization process is to end the CDATA section before the character, output the character using a character reference or entity reference, and open a new CDATA section for any further characters in the text node. Note, however, that some code conversion libraries at the time of writing do not return an error or exception when a character is missing from the encoding, making the task of ensuring that data is not corrupted on serialization more difficult.

IDL Definition

interface CDATASection : Text { };

Interface DocumentType

Each Documenthas a doctype attribute whose value is eithernull or a DocumentType object. TheDocumentType interface in the DOM Core provides an interface to the list of entities that are defined for the document, and little else because the effect of namespaces and the various XML schema efforts on DTD representation are not clearly understood as of this writing.

The DOM Level 2 doesn't support editingDocumentType nodes.

IDL Definition

interface DocumentType : Node { readonly attribute DOMString name; readonly attribute NamedNodeMap entities; readonly attribute NamedNodeMap notations; // Introduced in DOM Level 2: readonly attribute DOMString publicId; // Introduced in DOM Level 2: readonly attribute DOMString systemId; // Introduced in DOM Level 2: readonly attribute DOMString internalSubset; };

Attributes

entities of type NamedNodeMap, readonly

A NamedNodeMapcontaining the general entities, both external and internal, declared in the DTD. Parameter entities are not contained. Duplicates are discarded. For example in:

]>

the interface provides access to foo and the first declaration of bar but not the second declaration ofbar or baz. Every node in this map also implements the Entityinterface.
The DOM Level 2 does not support editing entities, thereforeentities cannot be altered in any way.

internalSubset of type DOMString, readonly, introduced in DOM Level 2

The internal subset as a string.

Note: The actual content returned depends on how much information is available to the implementation. This may vary depending on various parameters, including the XML processor used to build the document.

name of type DOMString, readonly

The name of DTD; i.e., the name immediately following theDOCTYPE keyword.

notations of type NamedNodeMap, readonly

A NamedNodeMapcontaining the notations declared in the DTD. Duplicates are discarded. Every node in this map also implements the Notationinterface.
The DOM Level 2 does not support editing notations, thereforenotations cannot be altered in any way.

publicId of type DOMString, readonly, introduced in DOM Level 2

The public identifier of the external subset.

systemId of type DOMString, readonly, introduced in DOM Level 2

The system identifier of the external subset.

Interface Notation

This interface represents a notation declared in the DTD. A notation either declares, by name, the format of an unparsed entity (see section 4.7 of the XML 1.0 specification [XML]), or is used for formal declaration of processing instruction targets (see section 2.6 of the XML 1.0 specification [XML]). The nodeNameattribute inherited from Node is set to the declared name of the notation.

The DOM Level 1 does not support editing Notationnodes; they are therefore readonly.

A Notation node does not have any parent.

IDL Definition

interface Notation : Node { readonly attribute DOMString publicId; readonly attribute DOMString systemId; };

Attributes

publicId of type DOMString, readonly

The public identifier of this notation. If the public identifier was not specified, this is null.

systemId of type DOMString, readonly

The system identifier of this notation. If the system identifier was not specified, this is null.

Interface Entity

This interface represents an entity, either parsed or unparsed, in an XML document. Note that this models the entity itself_not_ the entity declaration. Entitydeclaration modeling has been left for a later Level of the DOM specification.

The nodeName attribute that is inherited from Node contains the name of the entity.

An XML processor may choose to completely expand entities before the structure model is passed to the DOM; in this case there will be no EntityReference nodes in the document tree.

XML does not mandate that a non-validating XML processor read and process entity declarations made in the external subset or declared in external parameter entities. This means that parsed entities declared in the external subset need not be expanded by some classes of applications, and that the replacement value of the entity may not be available. When the replacement value is available, the corresponding Entity node's child list represents the structure of that replacement text. Otherwise, the child list is empty.

The DOM Level 2 does not support editing Entitynodes; if a user wants to make changes to the contents of anEntity, every related EntityReference node has to be replaced in the structure model by a clone of theEntity's contents, and then the desired changes must be made to each of those clones instead. Entity nodes and all their descendants are readonly.

An Entity node does not have any parent.

Note: If the entity contains an unbound namespace prefix, the namespaceURI of the corresponding node in the Entity node subtree is null. The same is true for EntityReference nodes that refer to this entity, when they are created using thecreateEntityReference method of the Document interface. The DOM Level 2 does not support any mechanism to resolve namespace prefixes.

IDL Definition

interface Entity : Node { readonly attribute DOMString publicId; readonly attribute DOMString systemId; readonly attribute DOMString notationName; };

Attributes

notationName of type DOMString, readonly

For unparsed entities, the name of the notation for the entity. For parsed entities, this is null.

publicId of type DOMString, readonly

The public identifier associated with the entity, if specified. If the public identifier was not specified, this isnull.

systemId of type DOMString, readonly

The system identifier associated with the entity, if specified. If the system identifier was not specified, this isnull.

Interface EntityReference

EntityReference objects may be inserted into the structure model when an entity reference is in the source document, or when the user wishes to insert an entity reference. Note that character references and references to predefined entities are considered to be expanded by the HTML or XML processor so that characters are represented by their Unicode equivalent rather than by an entity reference. Moreover, the XML processor may completely expand references to entities while building the structure model, instead of providing EntityReference objects. If it does provide such objects, then for a givenEntityReference node, it may be that there is no Entity node representing the referenced entity. If such an Entity exists, then the subtree of the EntityReference node is in general a copy of the Entity node subtree. However, this may not be true when an entity contains an unbound namespace prefix. In such a case, because the namespace prefix resolution depends on where the entity reference is, the descendants of theEntityReference node may be bound to different namespace URIs.

As for Entitynodes, EntityReference nodes and all their descendants are readonly.

IDL Definition

interface EntityReference : Node { };

Interface ProcessingInstruction

The ProcessingInstruction interface represents a "processing instruction", used in XML as a way to keep processor-specific information in the text of the document.

IDL Definition

interface ProcessingInstruction : Node { readonly attribute DOMString target; attribute DOMString data; // raises(DOMException) on setting

};

Attributes

data of type DOMString

The content of this processing instruction. This is from the first non white space character after the target to the character immediately preceding the ?>.

Exceptions on setting

target of type DOMString, readonly

The target of this processing instruction. XML defines this as being the first tokenfollowing the markup that begins the processing instruction.