Attr

Class Overview

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 attributes parentNode, previousSibling, and nextSibling have a null value for Attr 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 that Attr 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 Attr instance 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 or EntityReference nodes (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.

See also the Document Object Model (DOM) Level 2 Core Specification.

Summary

[Expand] Inherited Constants

From interface org.w3c.dom.Node 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_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 Text node.

[Expand] Inherited Methods

From interface org.w3c.dom.Node abstract Node appendChild(Node newChild) Adds the node newChild to the end of the list of children of this node. abstract Node cloneNode(boolean deep) Returns a duplicate of this node, i.e., serves as a generic copy constructor for nodes. abstract NamedNodeMap getAttributes() A NamedNodeMap containing the attributes of this node (if it is an Element) or null otherwise. abstract NodeList getChildNodes() A NodeList that contains all children of this node. abstract Node getFirstChild() The first child of this node. abstract Node getLastChild() The last child of this node. abstract String getLocalName() Returns the local part of the qualified name of this node. abstract String getNamespaceURI() The namespace URI of this node, or null if it is unspecified. abstract Node getNextSibling() The node immediately following this node. abstract String getNodeName() The name of this node, depending on its type; see the table above. abstract short getNodeType() A code representing the type of the underlying object, as defined above. abstract String getNodeValue() Returns the value of this node, depending on its type; see the table above. abstract Document getOwnerDocument() The Document object associated with this node. abstract Node getParentNode() The parent of this node. abstract String getPrefix() Returns the namespace prefix of this node, or null if it is unspecified. abstract Node getPreviousSibling() The node immediately preceding this node. abstract boolean hasAttributes() Returns whether this node (if it is an element) has any attributes. abstract boolean hasChildNodes() Returns whether this node has any children. abstract Node insertBefore(Node newChild, Node refChild) Inserts the node newChild before the existing child node refChild. abstract boolean isSupported(String feature, String version) Tests whether the DOM implementation implements a specific feature and that feature is supported by this node. abstract 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. abstract Node removeChild(Node oldChild) Removes the child node indicated by oldChild from the list of children, and returns it. abstract Node replaceChild(Node newChild, Node oldChild) Replaces the child node oldChild with newChild in the list of children, and returns the oldChild node. abstract void setNodeValue(String nodeValue) Sets the value of this node, depending on its type; see the table above. abstract void setPrefix(String prefix) Sets the namespace prefix of this node.