DeferredAttrImpl.javaAPI DocJava SE 5 API6774Fri Aug 26 14:55:42 BST


public final class DeferredAttrImpl extends AttrImpl implements DeferredNode
Attribute represents an XML-style attribute of an Element. Typically, the allowable values are controlled by its declaration in the Document Type Definition (DTD) governing this kind of document.

If the attribute has not been explicitly assigned a value, but has been declared in the DTD, it will exist and have that default. Only if neither the document nor the DTD specifies a value will the Attribute really be considered absent and have no value; in that case, querying the attribute will return null.

Attributes may have multiple children that contain their data. (XML allows attributes to contain entity references, and tokenized attribute types such as NMTOKENS may have a child for each token.) For convenience, the Attribute object's getValue() method returns the string version of the attribute's value.

Attributes are not children of the Elements they belong to, in the usual sense, and have no valid Parent reference. However, the spec says they _do_ belong to a specific Element, and an INUSE exception is to be thrown if the user attempts to explicitly share them between elements.

Note that Elements do not permit attributes to appear to be shared (see the INUSE exception), so this object's mutability is officially not an issue.

DeferredAttrImpl inherits from AttrImpl which does not support Namespaces. DeferredAttrNSImpl, which inherits from AttrNSImpl, does.

Andy Clark, IBM
Arnaud Le Hors, IBM
$Id:,v 1.19 2003/01/16 22:53:44 elena Exp $

Fields Summary
static final long
Serialization version.
protected transient int
Node index.
Constructors Summary
DeferredAttrImpl(DeferredDocumentImpl ownerDocument, int nodeIndex)
This is the deferred constructor. Only the fNodeIndex is given here. All other data, can be requested from the ownerDocument via the index.

    // Constructors

        super(ownerDocument, null);

        fNodeIndex = nodeIndex;

Methods Summary
public intgetNodeIndex()
Returns the node index.

        return fNodeIndex;
protected voidsynchronizeChildren()
Synchronizes the node's children with the internal structure. Fluffing the children at once solves a lot of work to keep the two structures in sync. The problem gets worse when editing the tree -- this makes it a lot easier.

        DeferredDocumentImpl ownerDocument =
            (DeferredDocumentImpl) ownerDocument();
        ownerDocument.synchronizeChildren(this, fNodeIndex);
protected voidsynchronizeData()
Synchronizes the data (name and value) for fast nodes.

        // no need to sync in the future

        // fluff data
        DeferredDocumentImpl ownerDocument =
            (DeferredDocumentImpl) ownerDocument();
        name = ownerDocument.getNodeName(fNodeIndex);
        int extra = ownerDocument.getNodeExtra(fNodeIndex);
        isSpecified((extra & SPECIFIED) != 0);
        isIdAttribute((extra & ID) != 0);

        int extraNode = ownerDocument.getLastChild(fNodeIndex);
        type = ownerDocument.getTypeInfo(extraNode);