org.apache.xerces.dom
Class EntityReferenceImpl
java.lang.Object
|
+--org.apache.xerces.dom.NodeImpl
|
+--org.apache.xerces.dom.ChildNode
|
+--org.apache.xerces.dom.ParentNode
|
+--org.apache.xerces.dom.EntityReferenceImpl
- All Implemented Interfaces:
- java.lang.Cloneable, org.w3c.dom.EntityReference, org.w3c.dom.events.EventTarget, org.w3c.dom.Node, org.apache.xerces.dom3.Node3, org.w3c.dom.NodeList, java.io.Serializable
- Direct Known Subclasses:
- DeferredEntityReferenceImpl
- public class EntityReferenceImpl
- extends ParentNode
- implements org.w3c.dom.EntityReference
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.
An XML processor has the alternative of fully expanding Entities
into the normal document tree. If it does so, no EntityReference nodes
will appear.
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.
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.
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.
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.)
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.
- Since:
- PR-DOM-Level-1-19980818.
- Version:
- $Id: EntityReferenceImpl.java,v 1.17 2002/01/29 01:15:07 lehors Exp $
- Author:
- Arnaud Le Hors, IBM, Joe Kesselman, IBM, Andy Clark, IBM, Ralf Pfeiffer, IBM
- See Also:
- Serialized Form
Field Summary |
protected java.lang.String |
name
Name of Entity referenced |
Fields inherited from class org.apache.xerces.dom.NodeImpl |
ELEMENT_DEFINITION_NODE, FIRSTCHILD, flags, HASSTRING, IGNORABLEWS, OWNED, ownerNode, READONLY, SPECIFIED, SYNCCHILDREN, SYNCDATA, UNNORMALIZED |
Fields inherited from interface org.w3c.dom.Node |
ATTRIBUTE_NODE, CDATA_SECTION_NODE, COMMENT_NODE, DOCUMENT_FRAGMENT_NODE, DOCUMENT_NODE, DOCUMENT_TYPE_NODE, ELEMENT_NODE, ENTITY_NODE, ENTITY_REFERENCE_NODE, NOTATION_NODE, PROCESSING_INSTRUCTION_NODE, TEXT_NODE |
Fields inherited from interface org.apache.xerces.dom3.Node3 |
TREE_POSITION_ANCESTOR, TREE_POSITION_DESCENDANT, TREE_POSITION_DISCONNECTED, TREE_POSITION_EQUIVALENT, TREE_POSITION_FOLLOWING, TREE_POSITION_PRECEDING, TREE_POSITION_SAME_NODE |
Method Summary |
org.w3c.dom.Node |
cloneNode(boolean deep)
Clone node. |
java.lang.String |
getNodeName()
Returns the name of the entity referenced |
short |
getNodeType()
A short integer indicating what type of node this is. |
protected void |
synchronizeChildren()
EntityReference's children are a reflection of those defined in the
named Entity. |
Methods inherited from class org.apache.xerces.dom.ParentNode |
getChildNodes, getChildNodesUnoptimized, getFirstChild, getLastChild, getLength, getOwnerDocument, getTextContent, hasChildNodes, insertBefore, isEqualNode, item, normalize, removeChild, replaceChild, setReadOnly, setTextContent |
Methods inherited from class org.apache.xerces.dom.NodeImpl |
addEventListener, appendChild, changed, changes, compareTreePosition, dispatchEvent, getAttributes, getBaseURI, getInterface, getLocalName, getNamespaceURI, getNodeValue, getPrefix, getReadOnly, getUserData, getUserData, hasAttributes, isSameNode, isSupported, lookupNamespacePrefix, lookupNamespaceURI, needsSyncChildren, removeEventListener, setNodeValue, setPrefix, setUserData, setUserData, synchronizeData, toString |
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait |
Methods inherited from interface org.w3c.dom.Node |
appendChild, getAttributes, getChildNodes, getFirstChild, getLastChild, getLocalName, getNamespaceURI, getNextSibling, getNodeValue, getOwnerDocument, getParentNode, getPrefix, getPreviousSibling, hasAttributes, hasChildNodes, insertBefore, isSupported, normalize, removeChild, replaceChild, setNodeValue, setPrefix |
name
protected java.lang.String name
- Name of Entity referenced
EntityReferenceImpl
public EntityReferenceImpl(CoreDocumentImpl ownerDoc,
java.lang.String name)
- Factory constructor.
getNodeType
public short getNodeType()
- 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.
- Specified by:
getNodeType
in interface org.w3c.dom.Node
- Overrides:
getNodeType
in class NodeImpl
getNodeName
public java.lang.String getNodeName()
- Returns the name of the entity referenced
- Specified by:
getNodeName
in interface org.w3c.dom.Node
- Overrides:
getNodeName
in class NodeImpl
cloneNode
public org.w3c.dom.Node cloneNode(boolean deep)
- Clone node.
- Specified by:
cloneNode
in interface org.w3c.dom.Node
- Overrides:
cloneNode
in class ParentNode
- Following copied from interface:
org.w3c.dom.Node
- Parameters:
deepIf
- true
, recursively clone the subtree under
the specified node; if false
, clone only the node
itself (and its attributes, if it is an Element
).- Returns:
- The duplicate node.
synchronizeChildren
protected void synchronizeChildren()
- EntityReference's children are a reflection of those defined in the
named Entity. This method creates them if they haven't been created yet.
This doesn't support editing the Entity though, since this only called
once for all.
- Overrides:
synchronizeChildren
in class ParentNode
Copyright © 1999-2002 Apache XML Project. All Rights Reserved.