/*
* RelevantNodes.java
*
* Copyright 2008 Mark Logic Corporation.
* All rights reserved.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package com.xmlcalabash.util;
import com.xmlcalabash.core.XProcConstants;
import com.xmlcalabash.core.XProcException;
import com.xmlcalabash.core.XProcRuntime;
import net.sf.saxon.s9api.*;
import net.sf.saxon.trans.XPathException;
import java.util.Iterator;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Created by IntelliJ IDEA.
* User: ndw
* Date: Apr 23, 2008
* Time: 12:39:28 PM
*
* All this really does is make XdmSequenceIterator Iterable.
*
* To change this template use File | Settings | File Templates.
*/
public class AxisNodes implements Iterable<XdmNode> {
public static final int NO_PIS = 0x01;
public static final int NO_COMMENTS = 0x02;
public static final int NO_WHITESPACE = 0x04;
public static final int NO_DOC = 0x08;
public static final int USE_WHEN = 0x10;
public static final int ALL = 0;
public static final int SIGNIFICANT = NO_PIS | NO_COMMENTS | NO_WHITESPACE;
public static final int PIPELINE = SIGNIFICANT | NO_DOC | USE_WHEN;
private static final int VALID_BITS = PIPELINE;
protected Logger logger = LoggerFactory.getLogger(AxisNodes.class);
private static QName use_when = new QName("", "use-when");
private static QName p_use_when = new QName(XProcConstants.NS_XPROC, "use-when");
private AxisNodesIter iter = null;
private XProcRuntime runtime = null;
private int filter = ALL;
public AxisNodes(XdmNode start, Axis axis) {
iter = new AxisNodesIter(start, axis);
}
public AxisNodes(XdmNode start, Axis axis, int filter) {
if ((filter | VALID_BITS) != VALID_BITS) {
throw new XProcException("Invalid filter passed to AxisNodes");
}
if ((filter & USE_WHEN) == USE_WHEN) {
throw new XProcException("Pointless use of USE_WHEN filter in AxisNodes");
}
this.filter = filter;
iter = new AxisNodesIter(start, axis);
}
public AxisNodes(XProcRuntime runtime, XdmNode start, Axis axis, int filter) {
if ((filter | VALID_BITS) != VALID_BITS) {
throw new XProcException("Invalid filter passed to AxisNodes");
}
this.runtime = runtime;
this.filter = filter;
iter = new AxisNodesIter(start, axis);
}
public Iterator<XdmNode> iterator() {
return iter;
}
private class AxisNodesIter implements Iterator<XdmNode> {
private XdmSequenceIterator iter = null;
private XdmNode next = null;
private boolean finished = false;
private boolean hasNext = false;
public AxisNodesIter(XdmNode start, Axis axis) {
iter = start.axisIterator(axis);
}
public boolean hasNext() {
hasNext = true;
// This code is funky because XdmSequenceIterator.hasNext() consumes an item
if (next == null) {
boolean hasNext = iter.hasNext();
finished = finished || !hasNext;
if (finished) {
return false;
}
// If we got here, there must be a next
next = (XdmNode) iter.next();
while (next != null && !ok(next)) {
if (iter.hasNext()) {
next = (XdmNode) iter.next();
} else {
next = null;
}
}
return ok(next);
} else {
return true;
}
}
public XdmNode next() {
if (!hasNext) {
hasNext();
hasNext = false;
}
XdmNode r = next;
next = null;
return r;
}
public void remove() {
throw new UnsupportedOperationException("Not supported!");
}
private boolean ok(XdmNode node) {
if (node == null) {
return false;
}
if (((filter & NO_DOC) == NO_DOC)
&& (node.getNodeKind() == XdmNodeKind.ELEMENT)
&& (XProcConstants.p_documentation.equals(node.getNodeName())
|| XProcConstants.p_pipeinfo.equals(node.getNodeName()))) {
return false;
}
if (((filter & NO_COMMENTS) == NO_COMMENTS)
&& node.getNodeKind() == XdmNodeKind.COMMENT) {
return false;
}
if (((filter & NO_PIS) == NO_PIS)
&& node.getNodeKind() == XdmNodeKind.PROCESSING_INSTRUCTION) {
return false;
}
if (node.getNodeKind() == XdmNodeKind.TEXT) {
if ((filter & NO_WHITESPACE) == NO_WHITESPACE) {
return !"".equals(node.toString().trim());
} else {
return true;
}
}
if (((filter & USE_WHEN) == USE_WHEN)
&& node.getNodeKind() == XdmNodeKind.ELEMENT) {
String expr = null;
if (XProcConstants.NS_XPROC.equals(node.getNodeName().getNamespaceURI())) {
expr = node.getAttributeValue(use_when);
}
if (!XProcConstants.NS_XPROC.equals(node.getNodeName().getNamespaceURI())) {
expr = node.getAttributeValue(p_use_when);
}
if (expr != null) {
return useWhen(node, expr);
} else {
return true;
}
}
return true;
}
private boolean useWhen(XdmNode element, String xpath) {
boolean use = false;
// FIXME: I don't think this is a good idea, but XProcConfiguration calls relevant nodes w/o a runtime...
if (runtime == null) {
logger.info("The use-when attribute has no effect on pipelines in a configuration file.");
return true;
}
try {
XPathCompiler xcomp = runtime.getProcessor().newXPathCompiler();
// FIXME: Static base URI here?
XdmSequenceIterator nsIter = element.axisIterator(Axis.NAMESPACE);
while (nsIter.hasNext()) {
XdmNode ns = (XdmNode) nsIter.next();
xcomp.declareNamespace(ns.getNodeName().getLocalName(),ns.getStringValue());
}
XPathExecutable xexec = null;
try {
xexec = xcomp.compile(xpath);
} catch (SaxonApiException sae) {
throw sae;
}
XPathSelector selector = xexec.load();
try {
use = selector.effectiveBooleanValue();
} catch (SaxonApiUncheckedException saue) {
Throwable sae = saue.getCause();
if (sae instanceof XPathException) {
XPathException xe = (XPathException) sae;
if ("http://www.w3.org/2005/xqt-errors".equals(xe.getErrorCodeNamespace()) && "XPDY0002".equals(xe.getErrorCodeLocalPart())) {
throw XProcException.dynamicError(26, element, "Expression refers to context when none is available: " + xpath);
} else {
throw saue;
}
} else {
throw saue;
}
}
} catch (SaxonApiException sae) {
if (S9apiUtils.xpathSyntaxError(sae)) {
throw XProcException.dynamicError(23, element, sae.getCause().getMessage());
} else {
throw new XProcException(sae);
}
}
return use;
}
}
}