| org.w3c.dom.Node | 
|  Known Indirect Subclasses | 
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.
 
The values of nodeName,
 nodeValue, and attributes vary according to the
 node type as follows:
 
| Interface | nodeName | nodeValue | attributes | 
|---|---|---|---|
| Attr | same as Attr.name | same as Attr.value | null | 
| CDATASection | "#cdata-section" | same as CharacterData.data, the
 content of the CDATA Section | null | 
| Comment | "#comment" | same as CharacterData.data, the
 content of the comment | null | 
| Document | "#document" | null | null | 
| DocumentFragment | "#document-fragment" | null | null | 
| DocumentType | same as DocumentType.name | null | null | 
| Element | same as Element.tagName | null | NamedNodeMap | 
| Entity | entity name | null | null | 
| EntityReference | name of entity referenced | null | null | 
| Notation | notation name | null | null | 
| ProcessingInstruction | same
 as ProcessingInstruction.target | same as ProcessingInstruction.data | null | 
| Text | "#text" | same as CharacterData.data, the content
 of the text node | null | 
See also the Document Object Model (DOM) Level 3 Core Specification.
| Constants | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| short | ATTRIBUTE_NODE | The node is an Attr. | |||||||||
| short | CDATA_SECTION_NODE | The node is a CDATASection. | |||||||||
| short | COMMENT_NODE | The node is a Comment. | |||||||||
| short | DOCUMENT_FRAGMENT_NODE | The node is a DocumentFragment. | |||||||||
| short | DOCUMENT_NODE | The node is a Document. | |||||||||
| short | DOCUMENT_POSITION_CONTAINED_BY | The node is contained by the reference node. | |||||||||
| short | DOCUMENT_POSITION_CONTAINS | The node contains the reference node. | |||||||||
| short | DOCUMENT_POSITION_DISCONNECTED | The two nodes are disconnected. | |||||||||
| short | DOCUMENT_POSITION_FOLLOWING | The node follows the reference node. | |||||||||
| short | DOCUMENT_POSITION_IMPLEMENTATION_SPECIFIC | The determination of preceding versus following is implementation-specific. | |||||||||
| short | DOCUMENT_POSITION_PRECEDING | The second node precedes the reference node. | |||||||||
| short | DOCUMENT_TYPE_NODE | The node is a DocumentType. | |||||||||
| short | ELEMENT_NODE | The node is an Element. | |||||||||
| short | ENTITY_NODE | The node is an Entity. | |||||||||
| short | ENTITY_REFERENCE_NODE | The node is an EntityReference. | |||||||||
| short | NOTATION_NODE | The node is a Notation. | |||||||||
| short | PROCESSING_INSTRUCTION_NODE | The node is a ProcessingInstruction. | |||||||||
| short | TEXT_NODE | The node is a Textnode. | |||||||||
| Public Methods | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Adds the node  newChildto the end of the list of children
 of this node. | |||||||||||
| Returns a duplicate of this node, i.e., serves as a generic copy
 constructor for nodes. | |||||||||||
| Compares the reference node, i.e. | |||||||||||
| A  NamedNodeMapcontaining the attributes of this node (if
 it is anElement) ornullotherwise. | |||||||||||
| The absolute base URI of this node or  nullif the
 implementation wasn't able to obtain an absolute URI. | |||||||||||
| A  NodeListthat contains all children of this node. | |||||||||||
| This method returns a specialized object which implements the
 specialized APIs of the specified feature and version, as specified
 in . | |||||||||||
| The first child of this node. | |||||||||||
| The last child of this node. | |||||||||||
| Returns the local part of the qualified name of this node. | |||||||||||
| The namespace URI of this node, or  nullif it is
 unspecified (see ). | |||||||||||
| The node immediately following this node. | |||||||||||
| The name of this node, depending on its type; see the table above. | |||||||||||
| A code representing the type of the underlying object, as defined above. | |||||||||||
| The value of this node, depending on its type; see the table above. | |||||||||||
| The  Documentobject associated with this node. | |||||||||||
| The parent of this node. | |||||||||||
| The namespace prefix of this node, or  nullif it is
 unspecified. | |||||||||||
| The node immediately preceding this node. | |||||||||||
| This attribute returns the text content of this node and its
 descendants. | |||||||||||
| Retrieves the object associated to a key on a this node. | |||||||||||
| Returns whether this node (if it is an element) has any attributes. | |||||||||||
| Returns whether this node has any children. | |||||||||||
| Inserts the node  newChildbefore the existing child noderefChild. | |||||||||||
| This method checks if the specified  namespaceURIis the
 default namespace or not. | |||||||||||
| Tests whether two nodes are equal. | |||||||||||
| Returns whether this node is the same node as the given one. | |||||||||||
| Tests whether the DOM implementation implements a specific feature and
 that feature is supported by this node, as specified in . | |||||||||||
| Look up the namespace URI associated to the given prefix, starting from
 this node. | |||||||||||
| Look up the prefix associated to the given namespace URI, starting from
 this node. | |||||||||||
| Puts all  Textnodes in the full depth of the sub-tree
 underneath thisNode, including attribute nodes, into a
 "normal" form where only structure (e.g., elements, comments,
 processing instructions, CDATA sections, and entity references)
 separatesTextnodes, i.e., there are neither adjacentTextnodes nor emptyTextnodes. | |||||||||||
| Removes the child node indicated by  oldChildfrom the list
 of children, and returns it. | |||||||||||
| Replaces the child node  oldChildwithnewChildin the list of children, and returns theoldChildnode. | |||||||||||
| The value of this node, depending on its type; see the table above. | |||||||||||
| The namespace prefix of this node, or  nullif it is
 unspecified. | |||||||||||
| This attribute returns the text content of this node and its
 descendants. | |||||||||||
| Associate an object to a key on this node. | |||||||||||
The node is an Attr.
The node is a CDATASection.
The node is a Comment.
The node is a DocumentFragment.
The node is a Document.
The node is contained by the reference node. A node which is contained is always following, too.
The node contains the reference node. A node which contains is always preceding, too.
The two nodes are disconnected. Order between disconnected nodes is always implementation-specific.
The node follows the reference node.
The determination of preceding versus following is implementation-specific.
The second node precedes the reference node.
The node is a DocumentType.
The node is an Element.
The node is an Entity.
The node is an EntityReference.
The node is a Notation.
The node is a ProcessingInstruction.
The node is a Text node.
Adds the node newChild to the end of the list of children
 of this node. If the newChild is already in the tree, it
 is first removed.
| newChild | 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 | 
|---|
| DOMException | HIERARCHY_REQUEST_ERR: Raised if this node is of a type that does not
   allow children of the type of the newChildnode, or if
   the node to append is one of this node's ancestors or this node
   itself, or if this node is of typeDocumentand the
   DOM application attempts to append a secondDocumentTypeorElementnode.WRONG_DOCUMENT_ERR: Raised if newChildwas created
   from a different document than the one that created this node.NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly or if the previous parent of the node being inserted is readonly. NOT_SUPPORTED_ERR: if the newChildnode is a child
   of theDocumentnode, this exception might be raised
   if the DOM implementation doesn't support the removal of theDocumentTypechild orElementchild. | 
|---|
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) and no user data. User
 data associated to the imported node is not carried over. However, if
 any UserDataHandlers has been specified along with the
 associated data these handlers will be called with the appropriate
 parameters before this method returns.
 
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 children it
 contains unless it is a deep clone. This includes text contained in
 an the Element since the text is contained in a child
 Text node. Cloning an Attr directly, as
 opposed to be cloned as part of an Element cloning
 operation, returns a specified attribute (specified is
 true). Cloning an Attr always clones its
 children, since they represent its value, no matter whether this is a
 deep clone or not. Cloning an EntityReference
 automatically constructs its subtree if a corresponding
 Entity is available, no matter whether this is a deep
 clone or not. 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.
| deep | If true, recursively clone the subtree under
   the specified node; iffalse, clone only the node
   itself (and its attributes, if it is anElement). | 
|---|
Compares the reference node, i.e. the node on which this method is being called, with a node, i.e. the one passed as a parameter, with regard to their position in the document and according to the document order.
| other | The node to compare against the reference node. | 
|---|
| DOMException | NOT_SUPPORTED_ERR: when the compared nodes are from different DOM implementations that do not coordinate to return consistent implementation-specific results. | 
|---|
A NamedNodeMap containing the attributes of this node (if
 it is an Element) or null otherwise.
The absolute base URI of this node or null if the
 implementation wasn't able to obtain an absolute URI. This value is
 computed as described in . However, when the Document
 supports the feature "HTML" [DOM Level 2 HTML]
 , the base URI is computed using first the value of the href
 attribute of the HTML BASE element if any, and the value of the
 documentURI attribute from the Document
 interface otherwise.
A NodeList that contains all children of this node. If
 there are no children, this is a NodeList containing no
 nodes.
This method returns a specialized object which implements the
 specialized APIs of the specified feature and version, as specified
 in . The specialized object may also be obtained by using
 binding-specific casting methods but is not necessarily expected to,
 as discussed in . This method also allow the implementation to
 provide specialized objects which do not support the Node
  interface.
| feature | The name of the feature requested. Note that any plus sign "+" prepended to the name of the feature will be ignored since it is not significant in the context of this method. | 
|---|---|
| version | This is the version number of the feature to test. | 
null if
   there is no object which implements interfaces associated with that
   feature. If the DOMObject returned by this method
   implements the Node interface, it must delegate to the
   primary core Node and not return results inconsistent
   with the primary core Node such as attributes,
   childNodes, etc.The first child of this node. If there is no such node, this returns
 null.
The last child of this node. If there is no such node, this returns
 null.
Returns the local part of the qualified name of this node.
 
For nodes of any type other than ELEMENT_NODE and
 ATTRIBUTE_NODE and nodes created with a DOM Level 1
 method, such as Document.createElement(), this is always
 null.
The namespace URI of this node, or null if it is
 unspecified (see ).
 
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 and
 ATTRIBUTE_NODE and nodes created with a DOM Level 1
 method, such as Document.createElement(), this is always
 null.
 
Note: Per the Namespaces in XML Specification [XML 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.
The node immediately following this node. If there is no such node,
 this returns null.
The name of this node, depending on its type; see the table above.
A code representing the type of the underlying object, as defined above.
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,
 including if the node is read-only.
| DOMException | DOMSTRING_SIZE_ERR: Raised when it would return more characters than
   fit in a DOMStringvariable on the implementation
   platform. | 
|---|
The Document object 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 is
 null.
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 is
 null.
The namespace prefix of this node, or null if it is
 unspecified. When it is defined to be null, setting it
 has no effect, including if the node is read-only.
 
Note that setting this attribute, when permitted, changes the
 nodeName attribute, which holds the qualified name, as
 well as the tagName and name attributes of
 the Element and Attr interfaces, when
 applicable.
 
Setting the prefix to null makes it unspecified,
 setting it to an empty string is implementation dependent.
 
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 the
 namespaceURI and localName do not change.
 
For nodes of any type other than ELEMENT_NODE and
 ATTRIBUTE_NODE and nodes created with a DOM Level 1
 method, such as createElement from the
 Document interface, this is always null.
The node immediately preceding this node. If there is no such node,
 this returns null.
This attribute returns the text content of this node and its
 descendants. When it is defined to be null, setting it
 has no effect. On setting, any possible children this node may have
 are removed and, if it the new string is not empty or
 null, replaced by a single Text node
 containing the string this attribute is set to.
 
 On getting, no serialization is performed, the returned string
 does not contain any markup. No whitespace normalization is performed
 and the returned string does not contain the white spaces in element
 content (see the attribute
 Text.isElementContentWhitespace). Similarly, on setting,
 no parsing is performed either, the input string is taken as pure
 textual content.
 
The string returned is made of the text content of this node
 depending on its type, as defined below:
 
| Node type | Content | 
|---|---|
| ELEMENT_NODE, ATTRIBUTE_NODE, ENTITY_NODE, ENTITY_REFERENCE_NODE, DOCUMENT_FRAGMENT_NODE | concatenation of the textContentattribute value of every child node, excluding COMMENT_NODE and
 PROCESSING_INSTRUCTION_NODE nodes. This is the empty string if the
 node has no children. | 
| TEXT_NODE, CDATA_SECTION_NODE, COMMENT_NODE, PROCESSING_INSTRUCTION_NODE | nodeValue | 
| DOCUMENT_NODE, DOCUMENT_TYPE_NODE, NOTATION_NODE | null | 
| DOMException | DOMSTRING_SIZE_ERR: Raised when it would return more characters than
   fit in a DOMStringvariable on the implementation
   platform. | 
|---|
Retrieves the object associated to a key on a this node. The object
 must first have been set to this node by calling
 setUserData with the same key.
| key | The key the object is associated to. | 
|---|
DOMUserData associated to the given
   key on this node, or null if there was none.Returns whether this node (if it is an element) has any attributes.
true if this node has any attributes,
   false otherwise.Returns whether this node has any children.
true if this node has any children,
   false otherwise.
Inserts the node newChild before the existing child node
 refChild. If refChild is null,
 insert newChild at the end of the list of children.
 
If newChild is a DocumentFragment object,
 all of its children are inserted, in the same order, before
 refChild. If the newChild is already in the
 tree, it is first removed.
 
Note: Inserting a node before itself is implementation dependent.
| newChild | The node to insert. | 
|---|---|
| refChild | The reference node, i.e., the node before which the new node must be inserted. | 
| DOMException | HIERARCHY_REQUEST_ERR: Raised if this node is of a type that does not
   allow children of the type of the newChildnode, or if
   the node to insert is one of this node's ancestors or this node
   itself, or if this node is of typeDocumentand the
   DOM application attempts to insert a secondDocumentTypeorElementnode.WRONG_DOCUMENT_ERR: Raised if newChildwas created
   from a different document than the one that created this node.NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly or if the parent of the node being inserted is readonly. NOT_FOUND_ERR: Raised if refChildis not a child of
   this node.NOT_SUPPORTED_ERR: if this node is of type Document,
   this exception might be raised if the DOM implementation doesn't
   support the insertion of aDocumentTypeorElementnode. | 
|---|
This method checks if the specified namespaceURI is the
 default namespace or not.
| namespaceURI | The namespace URI to look for. | 
|---|
true if the specified
   namespaceURI is the default namespace,
   false otherwise.Tests whether two nodes are equal.
 
This method tests for equality of nodes, not sameness (i.e.,
 whether the two nodes are references to the same object) which can be
 tested with Node.isSameNode(). All nodes that are the
 same will also be equal, though the reverse may not be true.
 
Two nodes are equal if and only if the following conditions are
 satisfied:
 
nodeName, localName,
 namespaceURI, prefix, nodeValue
 . This is: they are both null, or they have the same
 length and are character for character identical.
 attributes NamedNodeMaps are equal. This
 is: they are both null, or they have the same length and
 for each node that exists in one map there is a node that exists in
 the other map and is equal, although not necessarily at the same
 index.
 childNodes NodeLists are equal.
 This is: they are both null, or they have the same
 length and contain equal nodes at the same index. Note that
 normalization can affect equality; to avoid this, nodes should be
 normalized before being compared.
 DocumentType nodes to be equal, the following
 conditions must also be satisfied:
 publicId, systemId,
 internalSubset.
 entities
 NamedNodeMaps are equal.
 notations
 NamedNodeMaps are equal.
 ownerDocument, baseURI, and
 parentNode attributes, the specified
 attribute for Attr nodes, the schemaTypeInfo
  attribute for Attr and Element nodes, the
 Text.isElementContentWhitespace attribute for
 Text nodes, as well as any user data or event listeners
 registered on the nodes.
 Note: As a general rule, anything not mentioned in the description above is not significant in consideration of equality checking. Note that future versions of this specification may take into account more attributes and implementations conform to this specification are expected to be updated accordingly.
| arg | The node to compare equality with. | 
|---|
true if the nodes are equal,
   false otherwise.Returns whether this node is the same node as the given one.
 
This method provides a way to determine whether two
 Node references returned by the implementation reference
 the same object. When two Node references are references
 to the same object, even if through a proxy, the references may be
 used completely interchangeably, such that all attributes have the
 same values and calling the same DOM method on either reference
 always has exactly the same effect.
| other | The node to test against. | 
|---|
true if the nodes are the same,
   false otherwise.Tests whether the DOM implementation implements a specific feature and that feature is supported by this node, as specified in .
| feature | The name of the feature to test. | 
|---|---|
| version | This is the version number of the feature to test. | 
true if the specified feature is
   supported on this node, false otherwise.Look up the namespace URI associated to the given prefix, starting from
 this node.
 
See  for details on the algorithm used by this method.
| prefix | The prefix to look for. If this parameter is null, the method will return the default namespace URI
   if any. | 
|---|
null if
   none is found.Look up the prefix associated to the given namespace URI, starting from
 this node. The default namespace declarations are ignored by this
 method.
 
See  for details on the algorithm used by this method.
| namespaceURI | The namespace URI to look for. | 
|---|
null if none is found. If more than one prefix are
   associated to the namespace prefix, the returned namespace prefix
   is implementation dependent.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. If the parameter "normalize-characters" of the
 DOMConfiguration object attached to the
 Node.ownerDocument is true, this method
 will also fully normalize the characters of the Text
 nodes.
 
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 CDATASection nodes.
Removes the child node indicated by oldChild from the list
 of children, and returns it.
| oldChild | The node being removed. | 
|---|
| DOMException | NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly. NOT_FOUND_ERR: Raised if oldChildis not a child of
   this node.NOT_SUPPORTED_ERR: if this node is of type Document,
   this exception might be raised if the DOM implementation doesn't
   support the removal of theDocumentTypechild or theElementchild. | 
|---|
Replaces the child node oldChild with newChild
  in the list of children, and returns the oldChild node.
 
If newChild is a DocumentFragment object,
 oldChild is replaced by all of the
 DocumentFragment children, which are inserted in the
 same order. If the newChild is already in the tree, it
 is first removed.
 
Note: Replacing a node with itself is implementation dependent.
| newChild | The new node to put in the child list. | 
|---|---|
| oldChild | The node being replaced in the list. | 
| DOMException | HIERARCHY_REQUEST_ERR: Raised if this node is of a type that does not
   allow children of the type of the newChildnode, or if
   the node to put in is one of this node's ancestors or this node
   itself, or if this node is of typeDocumentand the
   result of the replacement operation would add a secondDocumentTypeorElementon theDocumentnode.WRONG_DOCUMENT_ERR: Raised if newChildwas created
   from a different document than the one that created this node.NO_MODIFICATION_ALLOWED_ERR: Raised if this node or the parent of the new node is readonly. NOT_FOUND_ERR: Raised if oldChildis not a child of
   this node.NOT_SUPPORTED_ERR: if this node is of type Document,
   this exception might be raised if the DOM implementation doesn't
   support the replacement of theDocumentTypechild orElementchild. | 
|---|
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,
 including if the node is read-only.
| DOMException | NO_MODIFICATION_ALLOWED_ERR: Raised when the node is readonly and if
   it is not defined to be null. | 
|---|
The namespace prefix of this node, or null if it is
 unspecified. When it is defined to be null, setting it
 has no effect, including if the node is read-only.
 
Note that setting this attribute, when permitted, changes the
 nodeName attribute, which holds the qualified name, as
 well as the tagName and name attributes of
 the Element and Attr interfaces, when
 applicable.
 
Setting the prefix to null makes it unspecified,
 setting it to an empty string is implementation dependent.
 
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 the
 namespaceURI and localName do not change.
 
For nodes of any type other than ELEMENT_NODE and
 ATTRIBUTE_NODE and nodes created with a DOM Level 1
 method, such as createElement from the
 Document interface, this is always null.
| DOMException | INVALID_CHARACTER_ERR: Raised if the specified prefix contains an
   illegal character according to the XML version in use specified in
   the Document.xmlVersionattribute.NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly. NAMESPACE_ERR: Raised if the specified prefixis
   malformed per the Namespaces in XML specification, if thenamespaceURIof this node isnull, if the
   specified prefix is "xml" and thenamespaceURIof this
   node is different from "
   http://www.w3.org/XML/1998/namespace", if this node is an attribute and the specified prefix is "xmlns" and
   thenamespaceURIof this node is different from "http://www.w3.org/2000/xmlns/", or if this node is an attribute and thequalifiedNameof
   this node is "xmlns" [XML Namespaces]
   . | 
|---|
This attribute returns the text content of this node and its
 descendants. When it is defined to be null, setting it
 has no effect. On setting, any possible children this node may have
 are removed and, if it the new string is not empty or
 null, replaced by a single Text node
 containing the string this attribute is set to.
 
 On getting, no serialization is performed, the returned string
 does not contain any markup. No whitespace normalization is performed
 and the returned string does not contain the white spaces in element
 content (see the attribute
 Text.isElementContentWhitespace). Similarly, on setting,
 no parsing is performed either, the input string is taken as pure
 textual content.
 
The string returned is made of the text content of this node
 depending on its type, as defined below:
 
| Node type | Content | 
|---|---|
| ELEMENT_NODE, ATTRIBUTE_NODE, ENTITY_NODE, ENTITY_REFERENCE_NODE, DOCUMENT_FRAGMENT_NODE | concatenation of the textContentattribute value of every child node, excluding COMMENT_NODE and
 PROCESSING_INSTRUCTION_NODE nodes. This is the empty string if the
 node has no children. | 
| TEXT_NODE, CDATA_SECTION_NODE, COMMENT_NODE, PROCESSING_INSTRUCTION_NODE | nodeValue | 
| DOCUMENT_NODE, DOCUMENT_TYPE_NODE, NOTATION_NODE | null | 
| DOMException | NO_MODIFICATION_ALLOWED_ERR: Raised when the node is readonly. | 
|---|
Associate an object to a key on this node. The object can later be
 retrieved from this node by calling getUserData with the
 same key.
| key | The key to associate the object to. | 
|---|---|
| data | The object to associate to the given key, or nullto remove any existing association to that key. | 
| handler | The handler to associate to that key, or null. | 
DOMUserData previously associated to
   the given key on this node, or null if there was none.