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Interface Attr

All Superinterfaces:

Node

public interfaceAttr

extendsNode

TheAttr interface represents an attribute in anElement object. Typically the allowable values for the attribute are defined in a document type definition.

Attr objects inherit theNode 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, theNode attributesparentNode,previousSibling, andnextSibling have anull value forAttr 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 aDocumentFragment. However, they can be associated withElement nodes contained within aDocumentFragment. In short, users and implementors of the DOM need to be aware thatAttr nodes have some things in common with other objects inheriting theNode 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 thenodeValue attribute on theAttr 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 theAttr node may be eitherText orEntityReference nodes (when these are in use; see the description ofEntityReference 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 theDocument Object Model (DOM) Level 2 Core Specification.

getName

public java.lang.StringgetName()

Returns the name of this attribute.

getSpecified

public booleangetSpecified()

If this attribute was explicitly given a value in the original document, this istrue; otherwise, it isfalse. Note that the implementation is in charge of this attribute, not the user. If the user changes the value of the attribute (even if it ends up having the same value as the default value) then thespecified flag is automatically flipped totrue. To re-specify the attribute as the default value from the DTD, the user must delete the attribute. The implementation will then make a new attribute available withspecified set tofalse and the default value (if one exists).
In summary: If the attribute has an assigned value in the document thenspecified istrue, and the value is the assigned value.If the attribute has no assigned value in the document and has a default value in the DTD, thenspecified isfalse, and the value is the default value in the DTD.If the attribute has no assigned value in the document and has a value of #IMPLIED in the DTD, then the attribute does not appear in the structure model of the document.If theownerElement attribute isnull (i.e. because it was just created or was set tonull by the various removal and cloning operations)specified istrue.

getValue

public java.lang.StringgetValue()

On retrieval, the value of the attribute is returned as a string. Character and general entity references are replaced with their values. See also the methodgetAttribute on theElement interface.
On setting, this creates aText node with the unparsed contents of the string. I.e. any characters that an XML processor would recognize as markup are instead treated as literal text. See also the methodsetAttribute on theElement interface.

Throws:

DOMException - NO_MODIFICATION_ALLOWED_ERR: Raised when the node is readonly.

setValue

public voidsetValue(java.lang.String value)              throwsDOMException

On retrieval, the value of the attribute is returned as a string. Character and general entity references are replaced with their values. See also the methodgetAttribute on theElement interface.
On setting, this creates aText node with the unparsed contents of the string. I.e. any characters that an XML processor would recognize as markup are instead treated as literal text. See also the methodsetAttribute on theElement interface.

Throws:

DOMException - NO_MODIFICATION_ALLOWED_ERR: Raised when the node is readonly.

getOwnerElement

publicElementgetOwnerElement()

TheElement node this attribute is attached to ornull if this attribute is not in use.

Since:

DOM Level 2