Node

A Node is an interface from which a number of DOM types inherit, and allows these various types to be treated (or tested) similarly.

The following interfaces all inherit from Node its methods and properties: Document, Element, CharacterData (which Text, Comment, and CDATASection inherit), ProcessingInstruction, DocumentFragment, DocumentType, Notation, Entity, EntityReference

These interfaces may return null in particular cases where the methods and properties are not relevant. They may throw an exception - for example when adding children to a node type for which no children can exist.

 

Properties

Inherits properties from its parents EventTarget.[1]

Node.attributes
...
Node.baseURI Read only
Returns a DOMString representing the base URL. The concept of base URL changes from one language to another; in HTML, it corresponds to the protocol, the domain name and the directory structure, that is all until the last '/'.
Node.baseURIObject
(Not available to web content.) The read-only nsIURI object representing the base URI for the element.
Node.childNodes Read only
Returns a live NodeList containing all the children of this node. NodeList being live means that if the children of the Node change, the NodeList object is automatically updated.
Node.firstChild Read only
Returns a Node representing the first direct child node of the node, or null if the node has no child.
Node.lastChild Read only
Returns a Node representing the last direct child node of the node, or null if the node has no child.
Node.localName Read only
Returns a DOMString representing the local part of the qualified name of an element. In Firefox 3.5 and earlier, the property upper-cases the local name for HTML elements (but not XHTML elements). In later versions, this does not happen, so the property is in lower case for both HTML and XHTML.
Though the specification requires localName to be defined on the Node interface, Gecko-based browsers implement it on the Element interface.
Node.namespaceURI Read only
The namespace URI of this node, or null if it is no namespace. In Firefox 3.5 and earlier, HTML elements are in no namespace. In later versions, HTML elements are in the http://www.w3.org/1999/xhtml namespace in both HTML and XML trees.
Though the specification requires namespaceURI to be defined on the Node interface, Gecko-based browsers implement it on the Element interface.
Node.nextSibling Read only
Returns a Node representing the next node in the tree, or null if there isn't such node.
Node.nodeName Read only
Returns a DOMString containing the name of the Node. The structure of the name will differ with the name type. E.g. An HTMLElement will contain the name of the corresponding tag, like 'audio' for an HTMLAudioElement, a Text node will have the '#text' string, or a Document node will have the '#document' string.
Node.nodePrincipal
A nsIPrincipal representing the node principal.
Node.nodeTypeRead only
Returns an unsigned short representing the type of the node. Possible values are:
Name Value
ELEMENT_NODE 1
ATTRIBUTE_NODE 2
TEXT_NODE 3
CDATA_SECTION_NODE 4
ENTITY_REFERENCE_NODE 5
ENTITY_NODE 6
PROCESSING_INSTRUCTION_NODE 7
COMMENT_NODE 8
DOCUMENT_NODE 9
DOCUMENT_TYPE_NODE 10
DOCUMENT_FRAGMENT_NODE 11
NOTATION_NODE 12
Node.nodeValue
Is a DOMString representing the value of an object. For most Node type, this returns null and any set operation is ignored. For nodes of type TEXT_NODE (Text objects), COMMENT_NODE (Comment objects), and PROCESSING_INSTRUCTION_NODE (ProcessingInstruction objects), the value corresponds to the text data contained in the object.
Node.ownerDocument Read only
Returns the Document that this node belongs to. If no document is associated with it, returns null.
Node.parentNode Read only
Returns a Node that is the parent of this node. If there is no such node, like if this node is the top of the tree or if doesn't participate in a tree, this property returns null.
Node.parentElement Read only
Returns an Element that is the parent of this node. If the node has no parent, or if that parent is not an Element, this property returns null.
Node.prefix
Is a DOMString representing the namespace prefix of the node, or null if no prefix is specified.
Though the specification requires localName to be defined on the Node interface, Gecko-based browsers implement it on the Element interface.
Node.previousSibling Read only
Returns a Node representing the previous node in the tree, or null if there isn't such node.
Node.textContent
Is a DOMString representing the textual content of an element and all its descendants.

Methods

Inherits methods from its parents EventTarget.[1]

Node.appendChild()
Insert a Node as the last child node of this element.
Node.cloneNode()
Clone a Node, and optionally, all of its contents. By default, it clones the content of the node.
Node.compareDocumentPosition()
 
Node.contains()
 
Node.getFeature()
...
Node.getUserData()
Allows a user to get some DOMUserData from the node.
Node.hasAttributes()
Returns a Boolean indicating if the element has any attributes, or not.
Node.hasChildNodes()
Returns a Boolean indicating if the element has any child nodes, or not.
Node.insertBefore
Inserts the first Node given in a parameter immediately before the second, child of this element, Node.
Node.isDefaultNamespace
 
Node.isEqualNode
 
Node.isSameNode
 
Node.isSupported
Returns a Boolean flag containing the result of a test whether the DOM implementation implements a specific feature and this feature is supported by the specific node.
Node.lookupPrefix
 
Node.lookupNamespaceURI
 
Node.normalize
Clean up all the text nodes under this element (merge adjacent, remove empty).
Node.removeChild
Removes a child node from the current element, which must be a child of the current node.
Node.replaceChild
Replaces one child Node of the current one with the second one given in parameter.
Node.setUserData
Allows a user to attach, or remove, DOMUserData to the node.
 

Examples

Browse all child nodes

The following function recursively cycles all child nodes of a node and executes a callback function upon them (and upon the parent node itself).

function DOMComb (oParent, oCallback) {
  if (oParent.hasChildNodes()) {
    for (var oNode = oParent.firstChild; oNode; oNode = oNode.nextSibling) {
      DOMComb(oNode, oCallback);
    }
  }
  oCallback.call(oParent);
}

Syntax

DOMComb(parentNode, callbackFunction);

Description

Recursively cycle all child nodes of parentNode and parentNode itself and execute the callbackFunction upon them as this objects.

Parameters

parentNode
The parent node (Node Object).
callbackFunction
The callback function (Function).

Sample usage

The following example send to the console.log the text content of the body:

function printContent () {
  if (this.nodeValue) { console.log(this.nodeValue); }
}

onload = function () {
  DOMComb(document.body, printContent);
};

Specifications

Specification Status Comment
DOM Living Standard Removed the following properties: attributes, namespaceURI, prefix, and localName.
Removed the following methods: isSupported(), hasAttributes(), isSameNode(), getFeature(), setUserData(), and getUserData().
Document Object Model (DOM) Level 3 Core Specification Recommendation The methods insertBefore(), replaceChild(), removeChild(), and appendChild() returns one more kind of error (NOT_SUPPORTED_ERR) if called on a Document.
The normalize() method has been modified so that Text node can also be normalized if the proper DOMConfiguration flag is set.
Added the following methods: compareDocumentPosition(), isSameNode(), lookupPrefix(), isDefaultNamespace(), lookupNamespaceURI(), isEqualNode(), getFeature(), setUserData(), and getUserData().
Added the following properties: baseURI and textContent.
Document Object Model (DOM) Level 2 Core Specification Recommendation The ownerDocument property was slightly modified so that DocumentFragment also returns null.
Added the following properties: namespaceURI, prefix, and localName.
Added the following methods: normalize(), isSupported() and hasAttributes().
Document Object Model (DOM) Level 1 Specification Recommendation Initial definition.

 

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
Basic support (Yes) 1.0 (1.7 or earlier) (Yes) (Yes) (Yes)
getFeature() Not supported Supported from 1.0 (1.7 or earlier) to 6.0 (6.0).
Removed in 7.0 (7.0)
? Not supported Not supported
getUserData(), setUserData() and hasAttributes() Not supported Supported from 1.0 (1.7 or earlier) to 21.0 (21.0).
Removed in 22.0 (22.0)
? Not supported Not supported
isSameNode() Not supported Supported from 1.0 (1.7 or earlier) to 9.0 (9.0).
Removed in 10.0 (10.0)
? Not supported Not supported
isSupported() ? Supported from 1.0 (1.7 or earlier) to 21.0 (21.0).
Removed in 22.0 (22.0)
? ? ?
Feature Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support (Yes) 1.0 (1.0) (Yes) (Yes) (Yes)
getFeature() Not supported Supported from 1.0 (1.7 or earlier) to 6.0 (6.0).
Removed in 7.0 (7.0)
? Not supported Not supported

[1] Webkit and Blink incorrectly doesn't make Node inherit from EventTarget.

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Last updated by: martco,