/*
* reserved comment block
* DO NOT REMOVE OR ALTER!
*/
/*
* Copyright 1999-2002,2004 The Apache Software Foundation.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* EntityReference models the XML &entityname; syntax, when used for
* entities defined by the DOM. Entities hardcoded into XML, such as
* character entities, should instead have been translated into text
* by the code which generated the DOM tree.
* <P>
* An XML processor has the alternative of fully expanding Entities
* into the normal document tree. If it does so, no EntityReference nodes
* will appear.
* <P>
* Similarly, non-validating XML processors are not required to read
* or process entity declarations made in the external subset or
* declared in external parameter entities. Hence, some applications
* may not make the replacement value available for Parsed Entities
* of these types.
* <P>
* EntityReference behaves as a read-only node, and the children of
* the EntityReference (which reflect those of the Entity, and should
* also be read-only) give its replacement value, if any. They are
* supposed to automagically stay in synch if the DocumentType is
* updated with new values for the Entity.
* <P>
* The defined behavior makes efficient storage difficult for the DOM
* implementor. We can't just look aside to the Entity's definition
* in the DocumentType since those nodes have the wrong parent (unless
* we can come up with a clever "imaginary parent" mechanism). We
* must at least appear to clone those children... which raises the
* issue of keeping the reference synchronized with its parent.
* This leads me back to the "cached image of centrally defined data"
* solution, much as I dislike it.
* <P>
* For now I have decided, since REC-DOM-Level-1-19980818 doesn't
* cover this in much detail, that synchronization doesn't have to be
* considered while the user is deep in the tree. That is, if you're
* looking within one of the EntityReferennce's children and the Entity
* changes, you won't be informed; instead, you will continue to access
* the same object -- which may or may not still be part of the tree.
* This is the same behavior that obtains elsewhere in the DOM if the
* subtree you're looking at is deleted from its parent, so it's
* acceptable here. (If it really bothers folks, we could set things
* up so deleted subtrees are walked and marked invalid, but that's
* not part of the DOM's defined behavior.)
* <P>
* As a result, only the EntityReference itself has to be aware of
* changes in the Entity. And it can take advantage of the same
* structure-change-monitoring code I implemented to support
* DeepNodeList.
*
* @xerces.internal
*
* @since PR-DOM-Level-1-19980818.
*/
public class DeferredEntityReferenceImpl
extends EntityReferenceImpl
implements DeferredNode {
//
// Constants
//
/** Serialization version. */
//
// Data
//
/** Node index. */
protected transient int fNodeIndex;
//
// Constructors
//
/**
* This is the deferred constructor. Only the fNodeIndex is given here.
* All other data, can be requested from the ownerDocument via the index.
*/
int nodeIndex) {
super(ownerDocument, null);
needsSyncData(true);
} // <init>(DeferredDocumentImpl,int)
//
// DeferredNode methods
//
/** Returns the node index. */
public int getNodeIndex() {
return fNodeIndex;
}
//
// Protected methods
//
/**
* Synchronize the entity data. This is special because of the way
* that the "fast" version stores the information.
*/
protected void synchronizeData() {
// no need to sychronize again
needsSyncData(false);
// get the node data
} // synchronizeData()
/** Synchronize the children. */
protected void synchronizeChildren() {
// no need to synchronize again
needsSyncChildren(false);
// get children
isReadOnly(false);
setReadOnly(true, true);
} // synchronizeChildren()
} // class DeferredEntityReferenceImpl