DOM - Node Object


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Node interface is the primary datatype for the entire Document Object Model. The node is used to represent a single XML element in the entire document tree.

A node can be any type that is an attribute node, a text node or any other node. The attributes nodeName, nodeValue and attributes are included as a mechanism to get at node information without casting down to the specific derived interface.

Attributes

The following table lists the attributes of the Node object −

Attribute Type Description
attributes NamedNodeMap This is of type NamedNodeMap containing the attributes of this node (if it is an Element) or null otherwise. This has been removed. Refer specs
baseURI DOMString It is used to specify absolute base URI of the node.
childNodes NodeList It is a NodeList that contains all children of this node. If there are no children, this is a NodeList containing no nodes.
firstChild Node It specifies the first child of a node.
lastChild Node It specifies the last child of a node.
localName DOMString It is used to specify the name of the local part of a node. This has been removed. Refer specs.
namespaceURI DOMString It specifies the namespace URI of a node. This has been removed. Refer specs
nextSibling Node It returns the node immediately following this node. If there is no such node, this returns null.
nodeName DOMString The name of this node, depending on its type.
nodeType unsigned short It is a code representing the type of the underlying object.
nodeValue DOMString It is used to specify the value of a node depending on their types.
ownerDocument Document It specifies the Document object associated with the node.
parentNode Node This property specifies the parent node of a node.
prefix DOMString This property returns the namespace prefix of a node. This has been removed. Refer specs
previousSibling Node This specifies the node immediately preceding the current node.
textContent DOMString This specifies the textual content of a node.

Node Types

We have listed the node types as below −

  • ELEMENT_NODE
  • ATTRIBUTE_NODE
  • ENTITY_NODE
  • ENTITY_REFERENCE_NODE
  • DOCUMENT_FRAGMENT_NODE
  • TEXT_NODE
  • CDATA_SECTION_NODE
  • COMMENT_NODE
  • PROCESSING_INSTRUCTION_NODE
  • DOCUMENT_NODE
  • DOCUMENT_TYPE_NODE
  • NOTATION_NODE

Methods

Below table lists the different Node Object methods −

S.No. Method & Description
1 appendChild(Node newChild)

This method adds a node after the last child node of the specified element node. It returns the added node.

2 cloneNode(boolean deep)

This method is used to create a duplicate node, when overridden in a derived class. It returns the duplicated node.

3 compareDocumentPosition(Node other)

This method is used to compare the position of the current node against a specified node according to the document order. Returns unsigned short, how the node is positioned relatively to the reference node.

4

getFeature(DOMString feature, DOMString version)

Returns the DOM Object which implements the specialized APIs of the specified feature and version, if any, or null if there is no object. This has been removed. Refer specs.

5

getUserData(DOMString key)

Retrieves the object associated to a key on this node. The object must first have been set to this node by calling the setUserData with the same key. Returns the DOMUserData associated to the given key on this node, or null if there was none. This has been removed. Refer specs.

6

hasAttributes()

Returns whether this node (if it is an element) has any attributes or not. Returns true if any attribute is present in the specified node else returns false. This has been removed. Refer specs.

7 hasChildNodes()

Returns whether this node has any children. This method returns true if the current node has child nodes otherwise false.

8 insertBefore(Node newChild, Node refChild)

This method is used to insert a new node as a child of this node, directly before an existing child of this node. It returns the node being inserted.

9 isDefaultNamespace(DOMString namespaceURI)

This method accepts a namespace URI as an argument and returns a Boolean with a value of true if the namespace is the default namespace on the given node or false if not.

10 isEqualNode(Node arg)

This method tests whether two nodes are equal. Returns true if the nodes are equal, false otherwise.

11

isSameNode(Node other)

This method returns whether current node is the same node as the given one. Returns true if the nodes are the same, false otherwise. This has been removed. Refer specs.

12

isSupported(DOMString feature, DOMString version)

This method returns whether the specified DOM module is supported by the current node. Returns true if the specified feature is supported on this node, false otherwise. This has been removed. Refer specs.

13 lookupNamespaceURI(DOMString prefix)

This method gets the URI of the namespace associated with the namespace prefix.

14 lookupPrefix(DOMString namespaceURI)

This method returns the closest prefix defined in the current namespace for the namespace URI. Returns an associated namespace prefix if found or null if none is found.

15 normalize()

Normalization adds all the text nodes including attribute nodes which define a normal form where structure of the nodes which contain elements, comments, processing instructions, CDATA sections, and entity references separates the text nodes, i.e, neither adjacent Text nodes nor empty Text nodes.

16 removeChild(Node oldChild)

This method is used to remove a specified child node from the current node. This returns the node removed.

17 replaceChild(Node newChild, Node oldChild)

This method is used to replace the old child node with a new node. This returns the node replaced.

18

setUserData(DOMString key, DOMUserData data, UserDataHandler handler)

This method associates an object to a key on this node. The object can later be retrieved from this node by calling getUserData with the same key. This returns the DOMUserData previously associated to the given key on this node. This has been removed. Refer specs.



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