protected ElementImpl() 
{

}

 public ElementImpl(CoreDocumentImpl ownerDoc,
    String name) 
{
    //
    // Constructors
    //
        super(ownerDoc);
        this.name = name;
        needsSyncData(true);    // synchronizeData will initialize attributes
}

Factory constructor.

 public Node cloneNode(boolean deep) 
{
        ElementImpl newnode = (ElementImpl) super.cloneNode(deep);
        // Replicate NamedNodeMap rather than sharing it.
        if (attributes != null) {
            newnode.attributes = (AttributeMap) attributes.cloneMap(newnode);
        }
        return newnode;
}

Return a duplicate copy of this Element. Note that its children will not be copied unless the "deep" flag is true, but Attributes are always replicated.

 public String getAttribute(String name) 
{
        if (needsSyncData()) {
            synchronizeData();
        }
        if (attributes == null) {
            return "";
        }
        Attr attr = (Attr)(attributes.getNamedItem(name));
        return (attr == null) ? "" : attr.getValue();
}

Look up a single Attribute by name. Returns the Attribute's string value, or an empty string (NOT null!) to indicate that the name did not map to a currently defined attribute.

Note: Attributes may contain complex node trees. This method returns the "flattened" string obtained from Attribute.getValue(). If you need the structure information, see getAttributeNode().

 public String getAttributeNS(String namespaceURI,
    String localName) 
{
        if (needsSyncData()) {
            synchronizeData();
        }
        if (attributes == null) {
            return "";
        }
        Attr attr = (Attr)(attributes.getNamedItemNS(namespaceURI, localName));
        return (attr == null) ? "" : attr.getValue();
}

Introduced in DOM Level 2.

Retrieves an attribute value by local name and namespace URI.

 public Attr getAttributeNode(String name) 
{
        if (needsSyncData()) {
            synchronizeData();
        }
        if (attributes == null) {
            return null;
        }
        return (Attr)attributes.getNamedItem(name);
}

Look up a single Attribute by name. Returns the Attribute Node, so its complete child tree is available. This could be important in XML, where the string rendering may not be sufficient information.

If no matching attribute is available, returns null.

 public Attr getAttributeNodeNS(String namespaceURI,
    String localName) 
{
        if (needsSyncData()) {
            synchronizeData();
        }
        if (attributes == null) {
            return null;
        }
        return (Attr)attributes.getNamedItemNS(namespaceURI, localName);
}

Retrieves an Attr node by local name and namespace URI.

 public NamedNodeMap getAttributes() 
{
        if (needsSyncData()) {
            synchronizeData();
        }
        if (attributes == null) {
            attributes = new AttributeMap(this, null);
        }
        return attributes;
}

Retrieve all the Attributes as a set. Note that this API is inherited from Node rather than specified on Element; in fact only Elements will ever have Attributes, but they want to allow folks to "blindly" operate on the tree as a set of Nodes.

 public String getBaseURI() 
{
        if (needsSyncData()) {
            synchronizeData();
        }
        // Absolute base URI is computed according to
        // XML Base (http://www.w3.org/TR/xmlbase/#granularity)
        // 1. The base URI specified by an xml:base attribute on the element,
        // if one exists
        if (attributes != null) {
            Attr attrNode = (Attr)attributes.getNamedItem("xml:base");
            if (attrNode != null) {
                String uri =  attrNode.getNodeValue();
                if (uri.length() != 0 ) {// attribute value is always empty string
                    try {
                       uri = new URI(uri).toString();
                    }
                    catch (com.sun.org.apache.xerces.internal.util.URI.MalformedURIException e) {
                        // This may be a relative URI.
                        // Make any parentURI into a URI object to use with the URI(URI, String) constructor
                        String parentBaseURI = (this.ownerNode != null) ? this.ownerNode.getBaseURI() : null;
                        if (parentBaseURI != null){
                            try{
                                uri = new URI(new URI(parentBaseURI), uri).toString();
                            }
                            catch (com.sun.org.apache.xerces.internal.util.URI.MalformedURIException ex){
                                // This should never happen: parent should have checked the URI and returned null if invalid.
                                return null;
                            }
                            return uri;
                        }
                        return null;
                    }
                    return uri;
                }
            }
        }
        // 2.the base URI of the element's parent element within the
        // document or external entity, if one exists
                // 3. the base URI of the document entity or external entity
                // containing the element
                // ownerNode serves as a parent or as document
                String baseURI = (this.ownerNode != null) ? this.ownerNode.getBaseURI() : null ;
        //base URI of parent element is not null
        if(baseURI != null){
            try {
                //return valid absolute base URI
               return new URI(baseURI).toString();
            }
            catch (com.sun.org.apache.xerces.internal.util.URI.MalformedURIException e){
                return null;
            }
        }
        return null;
}

DOM Level 3 WD - Experimental. Retrieve baseURI

 protected NamedNodeMapImpl getDefaultAttributes() 
{
        DocumentTypeImpl doctype =
            (DocumentTypeImpl) ownerDocument.getDoctype();
        if (doctype == null) {
            return null;
        }
        ElementDefinitionImpl eldef =
            (ElementDefinitionImpl)doctype.getElements()
                                               .getNamedItem(getNodeName());
        if (eldef == null) {
            return null;
        }
        return (NamedNodeMapImpl) eldef.getAttributes();
}

Get the default attributes.

 public NodeList getElementsByTagName(String tagname) 
{
        return new DeepNodeListImpl(this,tagname);
}

Returns a NodeList of all descendent nodes (children, grandchildren, and so on) which are Elements and which have the specified tag name.

Note: NodeList is a "live" view of the DOM. Its contents will change as the DOM changes, and alterations made to the NodeList will be reflected in the DOM.

 public NodeList getElementsByTagNameNS(String namespaceURI,
    String localName) 
{
        return new DeepNodeListImpl(this, namespaceURI, localName);
}

Introduced in DOM Level 2.

Returns a NodeList of all the Elements with a given local name and namespace URI in the order in which they would be encountered in a preorder traversal of the Document tree, starting from this node.

 public String getNodeName() 
{
        if (needsSyncData()) {
            synchronizeData();
        }
        return name;
}

Returns the element name

 public short getNodeType() 
{
        return Node.ELEMENT_NODE;
}

A short integer indicating what type of node this is. The named constants for this value are defined in the org.w3c.dom.Node interface.

 public TypeInfo getSchemaTypeInfo() 
{
        if(needsSyncData()) {
            synchronizeData();
        }
        return this;
}

Method getSchemaTypeInfo.

 public String getTagName() 
{
        if (needsSyncData()) {
            synchronizeData();
        }
        return name;
}

Returns the name of the Element. Note that Element.nodeName() is defined to also return the tag name.

This is case-preserving in XML. HTML should uppercasify it on the way in.

 public String getTypeName() 
{
        return null;
}

 public String getTypeNamespace() 
{
        return null;
}

 protected int getXercesAttribute(String namespaceURI,
    String localName) 
{
        if (needsSyncData()) {
            synchronizeData();
        }
        if (attributes == null) {
            return -1;
        }
        return attributes.getNamedItemIndex(namespaceURI, localName);
}

NON-DOM: get inded of an attribute

 public boolean hasAttribute(String name) 
{
        return getAttributeNode(name) != null;
}

Introduced in DOM Level 2.

 public boolean hasAttributeNS(String namespaceURI,
    String localName) 
{
        return getAttributeNodeNS(namespaceURI, localName) != null;
}

Introduced in DOM Level 2.

 public boolean hasAttributes() 
{
        if (needsSyncData()) {
            synchronizeData();
        }
        return (attributes != null && attributes.getLength() != 0);
}

Introduced in DOM Level 2.

 public boolean isDerivedFrom(String typeNamespaceArg,
    String typeNameArg,
    int derivationMethod) 
{
        return false;
}

Introduced in DOM Level 3.

Checks if a type is derived from another by restriction. See: http://www.w3.org/TR/DOM-Level-3-Core/core.html#TypeInfo-isDerivedFrom

 public boolean isEqualNode(Node arg) 
{
        if (!super.isEqualNode(arg)) {
            return false;
        }
        boolean hasAttrs = hasAttributes();
        if (hasAttrs != ((Element) arg).hasAttributes()) {
            return false;
        }
        if (hasAttrs) {
            NamedNodeMap map1 = getAttributes();
            NamedNodeMap map2 = ((Element) arg).getAttributes();
            int len = map1.getLength();
            if (len != map2.getLength()) {
                return false;
            }
            for (int i = 0; i <  len; i++) {
                Node n1 = map1.item(i);
                if (n1.getLocalName() == null) { // DOM Level 1 Node
                    Node n2 = map2.getNamedItem(n1.getNodeName());
                    if (n2 == null || !((NodeImpl) n1).isEqualNode(n2)) {
                        return false;
                    }
                }
                else {
                    Node n2 = map2.getNamedItemNS(n1.getNamespaceURI(),
                                                  n1.getLocalName());
                    if (n2 == null || !((NodeImpl) n1).isEqualNode(n2)) {
                        return false;
                    }
                }
            }
        }
        return true;
}

DOM Level 3 WD- Experimental. Override inherited behavior from NodeImpl and ParentNode to check on attributes

  void moveSpecifiedAttributes(ElementImpl el) 
{
        if (needsSyncData()) {
            synchronizeData();
        }
        if (el.hasAttributes()) {
            if (attributes == null) {
                attributes = new AttributeMap(this, null);
            }
            attributes.moveSpecifiedAttributes(el.attributes);
        }
}

 public  void normalize() 
{
        // No need to normalize if already normalized.
        if (isNormalized()) {
            return;
        }
        if (needsSyncChildren()) {
            synchronizeChildren();
        }
        ChildNode kid, next;
        for (kid = firstChild; kid != null; kid = next) {
            next = kid.nextSibling;
            // If kid is a text node, we need to check for one of two
            // conditions:
            //   1) There is an adjacent text node
            //   2) There is no adjacent text node, but kid is
            //      an empty text node.
            if ( kid.getNodeType() == Node.TEXT_NODE )
            {
                // If an adjacent text node, merge it with kid
                if ( next!=null && next.getNodeType() == Node.TEXT_NODE )
                {
                    ((Text)kid).appendData(next.getNodeValue());
                    removeChild( next );
                    next = kid; // Don't advance; there might be another.
                }
                else
                {
                    // If kid is empty, remove it
                    if ( kid.getNodeValue() == null || kid.getNodeValue().length() == 0 ) {
                        removeChild( kid );
                    }
                }
            }
            // Otherwise it might be an Element, which is handled recursively
            else if (kid.getNodeType() == Node.ELEMENT_NODE) {
                kid.normalize();
            }
        }
        // We must also normalize all of the attributes
        if ( attributes!=null )
        {
            for( int i=0; i< attributes.getLength(); ++i )
            {
                Node attr = attributes.item(i);
                attr.normalize();
            }
        }
        // changed() will have occurred when the removeChild() was done,
        // so does not have to be reissued.
        isNormalized(true);
}

In "normal form" (as read from a source file), there will never be two Text children in succession. But DOM users may create successive Text nodes in the course of manipulating the document. Normalize walks the sub-tree and merges adjacent Texts, as if the DOM had been written out and read back in again. This simplifies implementation of higher-level functions that may want to assume that the document is in standard form.

To normalize a Document, normalize its top-level Element child.

As of PR-DOM-Level-1-19980818, CDATA -- despite being a subclass of Text -- is considered "markup" and will _not_ be merged either with normal Text or with other CDATASections.

 protected  void reconcileDefaultAttributes() 
{
        if (attributes != null) {
            NamedNodeMapImpl defaults = getDefaultAttributes();
            attributes.reconcileDefaults(defaults);
        }
}

Reconcile default attributes.

 public  void removeAttribute(String name) 
{
        if (ownerDocument.errorChecking && isReadOnly()) {
            String msg = DOMMessageFormatter.formatMessage(DOMMessageFormatter.DOM_DOMAIN, "NO_MODIFICATION_ALLOWED_ERR", null);
            throw new DOMException(DOMException.NO_MODIFICATION_ALLOWED_ERR, msg);
        }
        if (needsSyncData()) {
            synchronizeData();
        }
        if (attributes == null) {
            return;
        }
        attributes.safeRemoveNamedItem(name);
}

Remove the named attribute from this Element. If the removed Attribute has a default value, it is immediately replaced thereby.

The default logic is actually implemented in NamedNodeMapImpl. PR-DOM-Level-1-19980818 doesn't fully address the DTD, so some of this behavior is likely to change in future versions. ?????

Note that this call "succeeds" even if no attribute by this name existed -- unlike removeAttributeNode, which will throw a not-found exception in that case.

 public  void removeAttributeNS(String namespaceURI,
    String localName) 
{
        if (ownerDocument.errorChecking && isReadOnly()) {
            String msg = DOMMessageFormatter.formatMessage(DOMMessageFormatter.DOM_DOMAIN, "NO_MODIFICATION_ALLOWED_ERR", null);
            throw new DOMException(DOMException.NO_MODIFICATION_ALLOWED_ERR, msg);
        }
        if (needsSyncData()) {
            synchronizeData();
        }
        if (attributes == null) {
            return;
        }
        attributes.safeRemoveNamedItemNS(namespaceURI, localName);
}

Introduced in DOM Level 2.

Removes an attribute by local name and namespace URI. If the removed attribute has a default value it is immediately replaced. The replacing attribute has the same namespace URI and local name, as well as the original prefix.

 public Attr removeAttributeNode(Attr oldAttr) throws DOMException 
{
        if (ownerDocument.errorChecking && isReadOnly()) {
            String msg = DOMMessageFormatter.formatMessage(DOMMessageFormatter.DOM_DOMAIN, "NO_MODIFICATION_ALLOWED_ERR", null);
            throw new DOMException(DOMException.NO_MODIFICATION_ALLOWED_ERR, msg);
        }
        if (needsSyncData()) {
            synchronizeData();
        }
        if (attributes == null) {
            String msg = DOMMessageFormatter.formatMessage(DOMMessageFormatter.DOM_DOMAIN, "NOT_FOUND_ERR", null);
            throw new DOMException(DOMException.NOT_FOUND_ERR, msg);
        }
        return (Attr) attributes.removeItem(oldAttr, true);
}

Remove the specified attribute/value pair. If the removed Attribute has a default value, it is immediately replaced.

NOTE: Specifically removes THIS NODE -- not the node with this name, nor the node with these contents. If the specific Attribute object passed in is not stored in this Element, we throw a DOMException. If you really want to remove an attribute by name, use removeAttribute().

  void rename(String name) 
{
        if (needsSyncData()) {
            synchronizeData();
        }
            this.name = name;
        reconcileDefaultAttributes();
}

 public  void setAttribute(String name,
    String value) 
{
                if (ownerDocument.errorChecking && isReadOnly()) {
                        String msg =
                                DOMMessageFormatter.formatMessage(
                                        DOMMessageFormatter.DOM_DOMAIN,
                                        "NO_MODIFICATION_ALLOWED_ERR",
                                        null);
                        throw new DOMException(DOMException.NO_MODIFICATION_ALLOWED_ERR, msg);
                }
                if (needsSyncData()) {
                        synchronizeData();
                }
                Attr newAttr = getAttributeNode(name);
                if (newAttr == null) {
                        newAttr = getOwnerDocument().createAttribute(name);
                        if (attributes == null) {
                                attributes = new AttributeMap(this, null);
                        }
                        newAttr.setNodeValue(value);
                        attributes.setNamedItem(newAttr);
                }
                else {
                        newAttr.setNodeValue(value);
                }
}

Add a new name/value pair, or replace the value of the existing attribute having that name. Note: this method supports only the simplest kind of Attribute, one whose value is a string contained in a single Text node. If you want to assert a more complex value (which XML permits, though HTML doesn't), see setAttributeNode(). The attribute is created with specified=true, meaning it's an explicit value rather than inherited from the DTD as a default. Again, setAttributeNode can be used to achieve other results.

 public  void setAttributeNS(String namespaceURI,
    String qualifiedName,
    String value) 
{
                if (ownerDocument.errorChecking && isReadOnly()) {
                        String msg =
                                DOMMessageFormatter.formatMessage(
                                        DOMMessageFormatter.DOM_DOMAIN,
                                        "NO_MODIFICATION_ALLOWED_ERR",
                                        null);
                        throw new DOMException(
                                DOMException.NO_MODIFICATION_ALLOWED_ERR,
                                msg);
                }
                if (needsSyncData()) {
                        synchronizeData();
                }
                int index = qualifiedName.indexOf(':");
                String prefix, localName;
                if (index <  0) {
                        prefix = null;
                        localName = qualifiedName;
                }
                else {
                        prefix = qualifiedName.substring(0, index);
                        localName = qualifiedName.substring(index + 1);
                }
                Attr newAttr = getAttributeNodeNS(namespaceURI, localName);
                if (newAttr == null) {
            // REVISIT: this is not efficient, we are creating twice the same
            //          strings for prefix and localName.
                        newAttr = getOwnerDocument().createAttributeNS(
                                        namespaceURI,
                                        qualifiedName);
                        if (attributes == null) {
                                attributes = new AttributeMap(this, null);
                        }
                        newAttr.setNodeValue(value);
                        attributes.setNamedItemNS(newAttr);
                }
                else {
            if (newAttr instanceof AttrNSImpl){
                String origNodeName = ((AttrNSImpl) newAttr).name;
                String newName = (prefix!=null) ? (prefix+":"+localName) : localName;
                ((AttrNSImpl) newAttr).name = newName;
                if (!newName.equals(origNodeName)) {
                    // Note: we can't just change the name of the attribute. Names have to be in sorted
                    // order in the attributes vector because a binary search is used to locate them.
                    // If the new name has a different prefix, the list may become unsorted.
                    // Maybe it would be better to resort the list, but the simplest
                    // fix seems to be to remove the old attribute and re-insert it.
                    // -- Norman.Walsh@Sun.COM, 2 Feb 2007
                    newAttr = (Attr) attributes.removeItem(newAttr, false);
                    attributes.addItem(newAttr);
                }
            }
            else {
                // This case may happen if user calls:
                //      elem.setAttribute("name", "value");
                //      elem.setAttributeNS(null, "name", "value");
                // This case is not defined by the DOM spec, we choose
                // to create a new attribute in this case and remove an old one from the tree
                // note this might cause events to be propagated or user data to be lost
                newAttr = new AttrNSImpl((CoreDocumentImpl)getOwnerDocument(), namespaceURI, qualifiedName, localName);
                attributes.setNamedItemNS(newAttr);
            }
                        newAttr.setNodeValue(value);
                }
}

Introduced in DOM Level 2.

Adds a new attribute. If the given namespaceURI is null or an empty string and the qualifiedName has a prefix that is "xml", the new attribute is bound to the predefined namespace "http://www.w3.org/XML/1998/namespace" [Namespaces]. If an attribute with the same local name and namespace URI is already present on the element, its prefix is changed to be the prefix part of the qualifiedName, and its value is changed to be the value parameter. This value is a simple string, it is not parsed as it is being set. So any markup (such as syntax to be recognized as an entity reference) is treated as literal text, and needs to be appropriately escaped by the implementation when it is written out. In order to assign an attribute value that contains entity references, the user must create an Attr node plus any Text and EntityReference nodes, build the appropriate subtree, and use setAttributeNodeNS or setAttributeNode to assign it as the value of an attribute.

 public Attr setAttributeNode(Attr newAttr) throws DOMException 
{
        if (needsSyncData()) {
            synchronizeData();
        }
        if (ownerDocument.errorChecking) {
            if (isReadOnly()) {
                String msg = DOMMessageFormatter.formatMessage(DOMMessageFormatter.DOM_DOMAIN, "NO_MODIFICATION_ALLOWED_ERR", null);
                throw new DOMException(
                                     DOMException.NO_MODIFICATION_ALLOWED_ERR,
                                     msg);
            }
            if (newAttr.getOwnerDocument() != ownerDocument) {
                String msg = DOMMessageFormatter.formatMessage(DOMMessageFormatter.DOM_DOMAIN, "WRONG_DOCUMENT_ERR", null);
                    throw new DOMException(DOMException.WRONG_DOCUMENT_ERR, msg);
            }
        }
        if (attributes == null) {
            attributes = new AttributeMap(this, null);
        }
        // This will throw INUSE if necessary
        return (Attr) attributes.setNamedItem(newAttr);
}

Add a new attribute/value pair, or replace the value of the existing attribute with that name.

This method allows you to add an Attribute that has already been constructed, and hence avoids the limitations of the simple setAttribute() call. It can handle attribute values that have arbitrarily complex tree structure -- in particular, those which had entity references mixed into their text.

 public Attr setAttributeNodeNS(Attr newAttr) throws DOMException 
{
        if (needsSyncData()) {
            synchronizeData();
        }
        if (ownerDocument.errorChecking) {
            if (isReadOnly()) {
                String msg = DOMMessageFormatter.formatMessage(DOMMessageFormatter.DOM_DOMAIN, "NO_MODIFICATION_ALLOWED_ERR", null);
                    throw new DOMException(
                                     DOMException.NO_MODIFICATION_ALLOWED_ERR,
                                     msg);
            }
            if (newAttr.getOwnerDocument() != ownerDocument) {
                String msg = DOMMessageFormatter.formatMessage(DOMMessageFormatter.DOM_DOMAIN, "WRONG_DOCUMENT_ERR", null);
                throw new DOMException(DOMException.WRONG_DOCUMENT_ERR, msg);
            }
        }
        if (attributes == null) {
            attributes = new AttributeMap(this, null);
        }
        // This will throw INUSE if necessary
        return (Attr) attributes.setNamedItemNS(newAttr);
}

Introduced in DOM Level 2.

Adds a new attribute. If an attribute with that local name and namespace URI is already present in the element, it is replaced by the new one.

 public  void setIdAttribute(String name,
    boolean makeId) 
{
        if (needsSyncData()) {
            synchronizeData();
        }
        Attr at = getAttributeNode(name);
                if( at == null){
                String msg = DOMMessageFormatter.formatMessage(
                                                                        DOMMessageFormatter.DOM_DOMAIN,
                                                                        "NOT_FOUND_ERR", null);
            throw new DOMException(DOMException.NOT_FOUND_ERR, msg);
                }
                if (ownerDocument.errorChecking) {
            if (isReadOnly()) {
                String msg = DOMMessageFormatter.formatMessage(DOMMessageFormatter.DOM_DOMAIN, "NO_MODIFICATION_ALLOWED_ERR", null);
                throw new DOMException(
                                     DOMException.NO_MODIFICATION_ALLOWED_ERR,
                                     msg);
            }
            if (at.getOwnerElement() != this) {
                String msg = DOMMessageFormatter.formatMessage(DOMMessageFormatter.DOM_DOMAIN, "NOT_FOUND_ERR", null);
                throw new DOMException(DOMException.NOT_FOUND_ERR, msg);
            }
        }
        ((AttrImpl) at).isIdAttribute(makeId);
        if (!makeId) {
            ownerDocument.removeIdentifier(at.getValue());
        }
        else {
            ownerDocument.putIdentifier(at.getValue(), this);
        }
}

DOM Level 3: register the given attribute node as an ID attribute

 public  void setIdAttributeNS(String namespaceURI,
    String localName,
    boolean makeId) 
{
        if (needsSyncData()) {
            synchronizeData();
        }
        //if namespace uri is empty string, set it to 'null'
        if (namespaceURI != null) {
            namespaceURI = (namespaceURI.length() == 0)? null : namespaceURI;
        }
        Attr at = getAttributeNodeNS(namespaceURI, localName);
                if( at == null){
                String msg = DOMMessageFormatter.formatMessage(
                                                                        DOMMessageFormatter.DOM_DOMAIN,
                                                                        "NOT_FOUND_ERR", null);
            throw new DOMException(DOMException.NOT_FOUND_ERR, msg);
                }
                if (ownerDocument.errorChecking) {
            if (isReadOnly()) {
                String msg = DOMMessageFormatter.formatMessage(DOMMessageFormatter.DOM_DOMAIN, "NO_MODIFICATION_ALLOWED_ERR", null);
                throw new DOMException(
                                     DOMException.NO_MODIFICATION_ALLOWED_ERR,
                                     msg);
            }
            if (at.getOwnerElement() != this) {
                String msg = DOMMessageFormatter.formatMessage(DOMMessageFormatter.DOM_DOMAIN, "NOT_FOUND_ERR", null);
                throw new DOMException(DOMException.NOT_FOUND_ERR, msg);
            }
        }
        ((AttrImpl) at).isIdAttribute(makeId);
        if (!makeId) {
            ownerDocument.removeIdentifier(at.getValue());
        }
        else {
            ownerDocument.putIdentifier(at.getValue(), this);
        }
}

DOM Level 3: register the given attribute node as an ID attribute

 public  void setIdAttributeNode(Attr at,
    boolean makeId) 
{
        if (needsSyncData()) {
            synchronizeData();
        }
        if (ownerDocument.errorChecking) {
            if (isReadOnly()) {
                String msg = DOMMessageFormatter.formatMessage(DOMMessageFormatter.DOM_DOMAIN, "NO_MODIFICATION_ALLOWED_ERR", null);
                throw new DOMException(
                                     DOMException.NO_MODIFICATION_ALLOWED_ERR,
                                     msg);
            }
            if (at.getOwnerElement() != this) {
                String msg = DOMMessageFormatter.formatMessage(DOMMessageFormatter.DOM_DOMAIN, "NOT_FOUND_ERR", null);
                throw new DOMException(DOMException.NOT_FOUND_ERR, msg);
            }
        }
        ((AttrImpl) at).isIdAttribute(makeId);
        if (!makeId) {
            ownerDocument.removeIdentifier(at.getValue());
        }
        else {
            ownerDocument.putIdentifier(at.getValue(), this);
        }
}

DOM Level 3: register the given attribute node as an ID attribute

  void setOwnerDocument(CoreDocumentImpl doc) 
{
        super.setOwnerDocument(doc);
        if (attributes != null) {
            attributes.setOwnerDocument(doc);
        }
}

NON-DOM set the ownerDocument of this node, its children, and its attributes

 public  void setReadOnly(boolean readOnly,
    boolean deep) 
{
        super.setReadOnly(readOnly,deep);
        if (attributes != null) {
            attributes.setReadOnly(readOnly,true);
        }
}

NON-DOM: Subclassed to flip the attributes' readonly switch as well.

 protected int setXercesAttributeNode(Attr attr) 
{
        if (needsSyncData()) {
            synchronizeData();
        }
        if (attributes == null) {
            attributes = new AttributeMap(this, null);
        }
        return attributes.addItem(attr);
}

NON-DOM: sets attribute node for this element

 protected  void setupDefaultAttributes() 
{
        NamedNodeMapImpl defaults = getDefaultAttributes();
        if (defaults != null) {
            attributes = new AttributeMap(this, defaults);
        }
}

Setup the default attributes.

 protected  void synchronizeData() 
{
        // no need to sync in the future
        needsSyncData(false);
        // we don't want to generate any event for this so turn them off
        boolean orig = ownerDocument.getMutationEvents();
        ownerDocument.setMutationEvents(false);
        // attributes
        setupDefaultAttributes();
        // set mutation events flag back to its original value
        ownerDocument.setMutationEvents(orig);
}

Synchronizes the data (name and value) for fast nodes.