public class

DocumentImpl

extends CoreDocumentImpl
implements DocumentEvent DocumentRange DocumentTraversal
java.lang.Object
   ↳ org.apache.xerces.dom.NodeImpl
     ↳ org.apache.xerces.dom.ChildNode
       ↳ org.apache.xerces.dom.ParentNode
         ↳ org.apache.xerces.dom.CoreDocumentImpl
           ↳ org.apache.xerces.dom.DocumentImpl
Known Direct Subclasses

Class Overview

The Document interface represents the entire HTML or XML document. Conceptually, it is the root of the document tree, and provides the primary access to the document's data.

Since elements, text nodes, comments, processing instructions, etc. cannot exist outside the context of a Document, the Document interface also contains the factory methods needed to create these objects. The Node objects created have a ownerDocument attribute which associates them with the Document within whose context they were created.

The DocumentImpl class also implements the DOM Level 2 DocumentTraversal interface. This interface is comprised of factory methods needed to create NodeIterators and TreeWalkers. The process of creating NodeIterator objects also adds these references to this document. After finishing with an iterator it is important to remove the object using the remove methods in this implementation. This allows the release of the references from the iterator objects to the DOM Nodes.

Note: When any node in the document is serialized, the entire document is serialized along with it.@xerces.internal

Summary

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Inherited Constants
From class org.apache.xerces.dom.NodeImpl
From interface org.w3c.dom.Node
Fields
protected Hashtable eventListeners Table for event listeners registered to this document nodes.
protected Vector iterators Iterators
protected boolean mutationEvents Bypass mutation events firing.
protected Vector ranges Ranges
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Inherited Fields
From class org.apache.xerces.dom.CoreDocumentImpl
From class org.apache.xerces.dom.ParentNode
From class org.apache.xerces.dom.ChildNode
From class org.apache.xerces.dom.NodeImpl
Public Constructors
DocumentImpl()
NON-DOM: Actually creating a Document is outside the DOM's spec, since it has to operate in terms of a particular implementation.
DocumentImpl(boolean grammarAccess)
Constructor.
DocumentImpl(DocumentType doctype)
For DOM2 support.
DocumentImpl(DocumentType doctype, boolean grammarAccess)
For DOM2 support.
Public Methods
Node cloneNode(boolean deep)
Deep-clone a document, including fixing ownerDoc for the cloned children.
Event createEvent(String type)
Introduced in DOM Level 2.
NodeIterator createNodeIterator(Node root, int whatToShow, NodeFilter filter, boolean entityReferenceExpansion)
Create and return a NodeIterator.
NodeIterator createNodeIterator(Node root, short whatToShow, NodeFilter filter)
NON-DOM extension: Create and return a NodeIterator.
Range createRange()
TreeWalker createTreeWalker(Node root, short whatToShow, NodeFilter filter)
NON-DOM extension: Create and return a TreeWalker.
TreeWalker createTreeWalker(Node root, int whatToShow, NodeFilter filter, boolean entityReferenceExpansion)
Create and return a TreeWalker.
DOMImplementation getImplementation()
Retrieve information describing the abilities of this particular DOM implementation.
Protected Methods
void addEventListener(NodeImpl node, String type, EventListener listener, boolean useCapture)
Introduced in DOM Level 2.
void copyEventListeners(NodeImpl src, NodeImpl tgt)
void dispatchAggregateEvents(NodeImpl node, AttrImpl enclosingAttr, String oldvalue, short change)
NON-DOM INTERNAL: Generate the "aggregated" post-mutation events DOMAttrModified and DOMSubtreeModified.
void dispatchAggregateEvents(NodeImpl node, DocumentImpl.EnclosingAttr ea)
NON-DOM INTERNAL: Convenience wrapper for calling dispatchAggregateEvents when the context was established by savedEnclosingAttr.
boolean dispatchEvent(NodeImpl node, Event event)
Introduced in DOM Level 2.
void dispatchEventToSubtree(Node n, Event e)
NON-DOM INTERNAL: DOMNodeInsertedIntoDocument and ...RemovedFrom...
void dispatchingEventToSubtree(Node n, Event e)
Dispatches event to the target node's descendents recursively
Vector getEventListeners(NodeImpl n)
Retreive event listener registered on a given node
void removeEventListener(NodeImpl node, String type, EventListener listener, boolean useCapture)
Introduced in DOM Level 2.
void saveEnclosingAttr(NodeImpl node)
NON-DOM INTERNAL: Pre-mutation context check, in preparation for later generating DOMAttrModified events.
void setEventListeners(NodeImpl n, Vector listeners)
Store event listener registered on a given node This is another place where we could use weak references! Indeed, the node here won't be GC'ed as long as some listener is registered on it, since the eventsListeners table will have a reference to the node.
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Inherited Methods
From class org.apache.xerces.dom.CoreDocumentImpl
From class org.apache.xerces.dom.ParentNode
From class org.apache.xerces.dom.ChildNode
From class org.apache.xerces.dom.NodeImpl
From class java.lang.Object
From interface org.w3c.dom.Document
From interface org.w3c.dom.Node
From interface org.w3c.dom.NodeList
From interface org.w3c.dom.events.DocumentEvent
From interface org.w3c.dom.events.EventTarget
From interface org.w3c.dom.ranges.DocumentRange
From interface org.w3c.dom.traversal.DocumentTraversal

Fields

protected Hashtable eventListeners

Table for event listeners registered to this document nodes.

protected Vector iterators

Iterators

protected boolean mutationEvents

Bypass mutation events firing.

protected Vector ranges

Ranges

Public Constructors

public DocumentImpl ()

NON-DOM: Actually creating a Document is outside the DOM's spec, since it has to operate in terms of a particular implementation.

public DocumentImpl (boolean grammarAccess)

Constructor.

public DocumentImpl (DocumentType doctype)

For DOM2 support. The createDocument factory method is in DOMImplementation.

public DocumentImpl (DocumentType doctype, boolean grammarAccess)

For DOM2 support.

Public Methods

public Node cloneNode (boolean deep)

Deep-clone a document, including fixing ownerDoc for the cloned children. Note that this requires bypassing the WRONG_DOCUMENT_ERR protection. I've chosen to implement it by calling importNode which is DOM Level 2.

Parameters
deep boolean, iff true replicate children
Returns
  • org.w3c.dom.Node

public Event createEvent (String type)

Introduced in DOM Level 2. Optional.

Create and return Event objects.

Parameters
type The eventType parameter specifies the type of Event interface to be created. If the Event interface specified is supported by the implementation this method will return a new Event of the interface type requested. If the Event is to be dispatched via the dispatchEvent method the appropriate event init method must be called after creation in order to initialize the Event's values. As an example, a user wishing to synthesize some kind of Event would call createEvent with the parameter "Events". The initEvent method could then be called on the newly created Event to set the specific type of Event to be dispatched and set its context information.
Returns
  • Newly created Event
Throws
DOMException NOT_SUPPORTED_ERR: Raised if the implementation does not support the type of Event interface requested

public NodeIterator createNodeIterator (Node root, int whatToShow, NodeFilter filter, boolean entityReferenceExpansion)

Create and return a NodeIterator. The NodeIterator is added to a list of NodeIterators so that it can be removed to free up the DOM Nodes it references.

Parameters
root The root of the iterator.
whatToShow The whatToShow mask.
filter The NodeFilter installed. Null means no filter.
entityReferenceExpansion true to expand the contents of EntityReference nodes

public NodeIterator createNodeIterator (Node root, short whatToShow, NodeFilter filter)

NON-DOM extension: Create and return a NodeIterator. The NodeIterator is added to a list of NodeIterators so that it can be removed to free up the DOM Nodes it references.

Parameters
root The root of the iterator.
whatToShow The whatToShow mask.
filter The NodeFilter installed. Null means no filter.

public Range createRange ()

public TreeWalker createTreeWalker (Node root, short whatToShow, NodeFilter filter)

NON-DOM extension: Create and return a TreeWalker.

Parameters
root The root of the iterator.
whatToShow The whatToShow mask.
filter The NodeFilter installed. Null means no filter.

public TreeWalker createTreeWalker (Node root, int whatToShow, NodeFilter filter, boolean entityReferenceExpansion)

Create and return a TreeWalker.

Parameters
root The root of the iterator.
whatToShow The whatToShow mask.
filter The NodeFilter installed. Null means no filter.
entityReferenceExpansion true to expand the contents of EntityReference nodes

public DOMImplementation getImplementation ()

Retrieve information describing the abilities of this particular DOM implementation. Intended to support applications that may be using DOMs retrieved from several different sources, potentially with different underlying representations.

Protected Methods

protected void addEventListener (NodeImpl node, String type, EventListener listener, boolean useCapture)

Introduced in DOM Level 2.

Register an event listener with this Node. A listener may be independently registered as both Capturing and Bubbling, but may only be registered once per role; redundant registrations are ignored.

Parameters
node node to add listener to
type Event name (NOT event group!) to listen for.
listener Who gets called when event is dispatched
useCapture True iff listener is registered on capturing phase rather than at-target or bubbling

protected void copyEventListeners (NodeImpl src, NodeImpl tgt)

protected void dispatchAggregateEvents (NodeImpl node, AttrImpl enclosingAttr, String oldvalue, short change)

NON-DOM INTERNAL: Generate the "aggregated" post-mutation events DOMAttrModified and DOMSubtreeModified. Both of these should be issued only once for each user-requested mutation operation, even if that involves multiple changes to the DOM. For example, if a DOM operation makes multiple changes to a single Attr before returning, it would be nice to generate only one DOMAttrModified, and multiple changes over larger scope but within a recognizable single subtree might want to generate only one DOMSubtreeModified, sent to their lowest common ancestor.

To manage this, use the "internal" versions of insert and remove with MUTATION_LOCAL, then make an explicit call to this routine at the higher level. Some examples now exist in our code.

Parameters
node The node to dispatch to
enclosingAttr The Attr node (if any) whose value has been changed as a result of the DOM operation. Null if none such.
oldvalue The String value previously held by the enclosingAttr. Ignored if none such.
change Type of modification to the attr. See MutationEvent.attrChange

protected void dispatchAggregateEvents (NodeImpl node, DocumentImpl.EnclosingAttr ea)

NON-DOM INTERNAL: Convenience wrapper for calling dispatchAggregateEvents when the context was established by savedEnclosingAttr.

Parameters
node node to dispatch to
ea description of Attr affected by current operation

protected boolean dispatchEvent (NodeImpl node, Event event)

Introduced in DOM Level 2.

Distribution engine for DOM Level 2 Events.

Event propagation runs as follows:

  1. Event is dispatched to a particular target node, which invokes this code. Note that the event's stopPropagation flag is cleared when dispatch begins; thereafter, if it has been set before processing of a node commences, we instead immediately advance to the DEFAULT phase.
  2. The node's ancestors are established as destinations for events. For capture and bubble purposes, node ancestry is determined at the time dispatch starts. If an event handler alters the document tree, that does not change which nodes will be informed of the event.
  3. CAPTURING_PHASE: Ancestors are scanned, root to target, for Capturing listeners. If found, they are invoked (see below).
  4. AT_TARGET: Event is dispatched to NON-CAPTURING listeners on the target node. Note that capturing listeners on this node are _not_ invoked.
  5. BUBBLING_PHASE: Ancestors are scanned, target to root, for non-capturing listeners.
  6. Default processing: Some DOMs have default behaviors bound to specific nodes. If this DOM does, and if the event's preventDefault flag has not been set, we now return to the target node and process its default handler for this event, if any.

Note that registration of handlers during processing of an event does not take effect during this phase of this event; they will not be called until the next time this node is visited by dispatchEvent. On the other hand, removals take effect immediately.

If an event handler itself causes events to be dispatched, they are processed synchronously, before processing resumes on the event which triggered them. Please be aware that this may result in events arriving at listeners "out of order" relative to the actual sequence of requests.

Note that our implementation resets the event's stop/prevent flags when dispatch begins. I believe the DOM's intent is that event objects be redispatchable, though it isn't stated in those terms.

Parameters
node node to dispatch to
event the event object to be dispatched to registered EventListeners
Returns
  • true if the event's preventDefault() method was invoked by an EventListener; otherwise false.

protected void dispatchEventToSubtree (Node n, Event e)

NON-DOM INTERNAL: DOMNodeInsertedIntoDocument and ...RemovedFrom... are dispatched to an entire subtree. This is the distribution code therefor. They DO NOT bubble, thanks be, but may be captured.

Similar to code in dispatchingEventToSubtree however this method is only used on the target node and does not start a dispatching chain on the sibling of the target node as this is not part of the subtree ***** At the moment I'm being sloppy and using the normal capture dispatcher on every node. This could be optimized hugely by writing a capture engine that tracks our position in the tree to update the capture chain without repeated chases up to root.

Parameters
n target node (that was directly inserted or removed)
e event to be sent to that node and its subtree

protected void dispatchingEventToSubtree (Node n, Event e)

Dispatches event to the target node's descendents recursively

Parameters
n node to dispatch to
e event to be sent to that node and its subtree

protected Vector getEventListeners (NodeImpl n)

Retreive event listener registered on a given node

protected void removeEventListener (NodeImpl node, String type, EventListener listener, boolean useCapture)

Introduced in DOM Level 2.

Deregister an event listener previously registered with this Node. A listener must be independently removed from the Capturing and Bubbling roles. Redundant removals (of listeners not currently registered for this role) are ignored.

Parameters
node node to remove listener from
type Event name (NOT event group!) to listen for.
listener Who gets called when event is dispatched
useCapture True iff listener is registered on capturing phase rather than at-target or bubbling

protected void saveEnclosingAttr (NodeImpl node)

NON-DOM INTERNAL: Pre-mutation context check, in preparation for later generating DOMAttrModified events. Determines whether this node is within an Attr

Parameters
node node to get enclosing attribute for

protected void setEventListeners (NodeImpl n, Vector listeners)

Store event listener registered on a given node This is another place where we could use weak references! Indeed, the node here won't be GC'ed as long as some listener is registered on it, since the eventsListeners table will have a reference to the node.