public interface Node
The Node interface is the primary datatype for the entire Document Object Model. It represents a single node in the document tree. While all objects implementing the Node interface expose methods for dealing with children, not all objects implementing the Node interface may have children. For example, Text nodes may not have children, and adding children to such nodes results in a DOMException being raised.
The attributes nodeName, nodeValue and attributes are included as a mechanism to get at node information without casting down to the specific derived interface. In cases where there is no obvious mapping of these attributes for a specific nodeType (e.g., nodeValue for an Element or attributes for a Comment ), this returns null. Note that the specialized interfaces may contain additional and more convenient mechanisms to get and set the relevant information.
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.
static final short ELEMENT_NODE
The node is an Element.
static final short ATTRIBUTE_NODE
The node is an Attr.
static final short TEXT_NODE
The node is a Text node.
static final short CDATA_SECTION_NODE
The node is a CDATASection.
static final short ENTITY_REFERENCE_NODE
The node is an EntityReference.
static final short ENTITY_NODE
The node is an Entity.
static final short PROCESSING_INSTRUCTION_NODE
The node is a ProcessingInstruction.
static final short COMMENT_NODE
The node is a Comment.
static final short DOCUMENT_NODE
The node is a Document.
static final short DOCUMENT_TYPE_NODE
The node is a DocumentType.
static final short DOCUMENT_FRAGMENT_NODE
The node is a DocumentFragment.
static final short NOTATION_NODE
The node is a Notation.
static final short DOCUMENT_POSITION_DISCONNECTED
The two nodes are disconnected. Order between disconnected nodes is always implementation-specific.
static final short DOCUMENT_POSITION_PRECEDING
The second node precedes the reference node.
static final short DOCUMENT_POSITION_FOLLOWING
The node follows the reference node.
static final short DOCUMENT_POSITION_CONTAINS
The node contains the reference node. A node which contains is always preceding, too.
static final short DOCUMENT_POSITION_CONTAINED_BY
The node is contained by the reference node. A node which is contained is always following, too.
static final short DOCUMENT_POSITION_IMPLEMENTATION_SPECIFIC
The determination of preceding versus following is implementation-specific.
String getNodeName()
The name of this node, depending on its type; see the table above.
String getNodeValue()
throws DOMException 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 DOMString variable on the implementation platform.void setNodeValue(String nodeValue)
throws DOMException 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.short getNodeType()
A code representing the type of the underlying object, as defined above.
Node getParentNode()
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.
NodeList getChildNodes()
A NodeList that contains all children of this node. If there are no children, this is a NodeList containing no nodes.
Node getFirstChild()
The first child of this node. If there is no such node, this returns null.
Node getLastChild()
The last child of this node. If there is no such node, this returns null.
Node getPreviousSibling()
The node immediately preceding this node. If there is no such node, this returns null.
Node getNextSibling()
The node immediately following this node. If there is no such node, this returns null.
NamedNodeMap getAttributes()
A NamedNodeMap containing the attributes of this node (if it is an Element) or null otherwise.
Document getOwnerDocument()
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.
Node insertBefore(Node newChild,
Node refChild)
throws DOMException 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 newChild node, or if the node to insert is one of this node's ancestors or this node itself, or if this node is of type Document and the DOM application attempts to insert a second DocumentType or Element node. newChild was created from a different document than the one that created this node. refChild is not a child of this node. Document, this exception might be raised if the DOM implementation doesn't support the insertion of a DocumentType or Element node.Node replaceChild(Node newChild,
Node oldChild)
throws DOMException 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 newChild node, or if the node to put in is one of this node's ancestors or this node itself, or if this node is of type Document and the result of the replacement operation would add a second DocumentType or Element on the Document node. newChild was created from a different document than the one that created this node. oldChild is not a child of this node. Document, this exception might be raised if the DOM implementation doesn't support the replacement of the DocumentType child or Element child.Node removeChild(Node oldChild)
throws DOMException 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. oldChild is not a child of this node. Document, this exception might be raised if the DOM implementation doesn't support the removal of the DocumentType child or the Element child.Node appendChild(Node newChild)
throws DOMException 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 DocumentFragment object, the entire contents of the document fragment are moved into the child list of this nodeDOMException - HIERARCHY_REQUEST_ERR: Raised if this node is of a type that does not allow children of the type of the newChild node, or if the node to append is one of this node's ancestors or this node itself, or if this node is of type Document and the DOM application attempts to append a second DocumentType or Element node. newChild was created from a different document than the one that created this node. newChild node is a child of the Document node, this exception might be raised if the DOM implementation doesn't support the removal of the DocumentType child or Element child.boolean hasChildNodes()
Returns whether this node has any children.
true if this node has any children, false otherwise.Node cloneNode(boolean deep)
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; if false, clone only the node itself (and its attributes, if it is an Element).void normalize()
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.
boolean isSupported(String feature,
String version) 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.String getNamespaceURI()
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.
String getPrefix()
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.
void setPrefix(String prefix)
throws DOMException 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.xmlVersion attribute. prefix is malformed per the Namespaces in XML specification, if the namespaceURI of this node is null, if the specified prefix is "xml" and the namespaceURI of 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 the namespaceURI of this node is different from "http://www.w3.org/2000/xmlns/", or if this node is an attribute and the qualifiedName of this node is "xmlns" [XML Namespaces] .String getLocalName()
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.
boolean hasAttributes()
Returns whether this node (if it is an element) has any attributes.
true if this node has any attributes, false otherwise.String getBaseURI()
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.
short compareDocumentPosition(Node other)
throws DOMException 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.String getTextContent()
throws DOMException 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 textContent attribute 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 DOMString variable on the implementation platform.void setTextContent(String textContent)
throws DOMException 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 textContent attribute 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.boolean isSameNode(Node other)
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.String lookupPrefix(String namespaceURI)
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.boolean isDefaultNamespace(String namespaceURI)
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.String lookupNamespaceURI(String prefix)
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.boolean isEqualNode(Node arg)
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.Object getFeature(String feature,
String version) 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.Object setUserData(String key,
Object data,
UserDataHandler handler) 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 null to 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.Object getUserData(String key)
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.
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