package net.sf.saxon.evpull;
import net.sf.saxon.om.NamePool;
import net.sf.saxon.om.NodeInfo;
import net.sf.saxon.trans.XPathException;
import net.sf.saxon.type.Type;
/**
* The class is an EventIterator that handles the events arising from an element constructor:
* that is, the start/end event pair for the element node, bracketing a sequence of events for the
* content of the element.
*
* <p>This class does not normalize the content (for example by merging adjacent text nodes). That is the job
* of the {@link ComplexContentProcessor}.</p>
*
* <p>The event stream consumed by a BracketedElementIterator may contain freestanding attribute and namespace nodes.
* The event stream delivered by a BracketedElementIterator, however, packages all attributes and namespaces as
* part of the startElement event.</p>
*/
public class BracketedElementIterator implements EventIterator {
private PullEvent start;
private EventIterator content;
private PullEvent pendingContent;
private PullEvent end;
private int state = INITIAL_STATE;
private static final int INITIAL_STATE = 0;
private static final int PROCESSING_FIRST_CHILD = 1;
private static final int PROCESSING_REMAINING_CHILDREN = 2;
private static final int REACHED_END_TAG = 3;
private static final int EXHAUSTED = 4;
/**
* Constructor
* @param start the StartElementEvent object
* @param content iterator that delivers the content of the element
* @param end the EndElementEvent object
*/
public BracketedElementIterator(PullEvent start, EventIterator content, PullEvent end) {
this.start = start;
this.content = EventStackIterator.flatten(content);
this.end = end;
state = 0;
}
/**
* Get the next event in the sequence
* @return the next event, or null when the sequence is exhausted
* @throws XPathException if a dynamic evaluation error occurs
*/
public PullEvent next() throws XPathException {
switch (state) {
case INITIAL_STATE:
while (true) {
PullEvent pe = content.next();
if (pe == null) {
pendingContent = null;
state = REACHED_END_TAG;
break;
} else if (pe instanceof NodeInfo) {
int k = ((NodeInfo)pe).getNodeKind();
if (k == Type.NAMESPACE) {
NamePool pool = ((NodeInfo)pe).getNamePool();
int nscode = pool.allocateNamespaceCode(
((NodeInfo)pe).getLocalPart(), ((NodeInfo)pe).getStringValue());
((StartElementEvent)start).addNamespace(nscode);
continue;
} else if (k == Type.ATTRIBUTE) {
((StartElementEvent)start).addAttribute((NodeInfo)pe);
continue;
} else if (k == Type.TEXT && ((NodeInfo)pe).getStringValueCS().length() == 0) {
// ignore a zero-length text node
continue;
}
// TODO: should also ignore a document node consisting solely of a zero-length text node
}
pendingContent = pe;
state = PROCESSING_FIRST_CHILD;
break;
}
((StartElementEvent)start).namespaceFixup();
return start;
case PROCESSING_FIRST_CHILD:
state = PROCESSING_REMAINING_CHILDREN;
return pendingContent;
case PROCESSING_REMAINING_CHILDREN:
PullEvent pe = content.next();
if (pe == null) {
state = EXHAUSTED;
return end;
} else {
return pe;
}
case REACHED_END_TAG:
state = EXHAUSTED;
return end;
case EXHAUSTED:
return null;
default:
throw new AssertionError("BracketedEventIterator state " + state);
}
}
/**
* Determine whether the EventIterator returns a flat sequence of events, or whether it can return
* nested event iterators
*
* @return true if the next() method is guaranteed never to return an EventIterator
*/
public boolean isFlatSequence() {
return true;
}
}
//
// The contents of this file are subject to the Mozilla Public License Version 1.0 (the "License");
// you may not use this file except in compliance with the License. You may obtain a copy of the
// License at http://www.mozilla.org/MPL/
//
// Software distributed under the License is distributed on an "AS IS" basis,
// WITHOUT WARRANTY OF ANY KIND, either express or implied.
// See the License for the specific language governing rights and limitations under the License.
//
// The Original Code is: all this file
//
// The Initial Developer of the Original Code is Michael H. Kay.
//
// Contributor(s):
//