/*
* SplitSequence.java
*
* Copyright 2008 Mark Logic Corporation.
* Portions Copyright 2007 Sun Microsystems, Inc.
* All rights reserved.
*
* The contents of this file are subject to the terms of either the GNU
* General Public License Version 2 only ("GPL") or the Common
* Development and Distribution License("CDDL") (collectively, the
* "License"). You may not use this file except in compliance with the
* License. You can obtain a copy of the License at
* https://xproc.dev.java.net/public/CDDL+GPL.html or
* docs/CDDL+GPL.txt in the distribution. See the License for the
* specific language governing permissions and limitations under the
* License. When distributing the software, include this License Header
* Notice in each file and include the License file at docs/CDDL+GPL.txt.
*/
package com.xmlcalabash.library;
import com.xmlcalabash.core.XProcException;
import com.xmlcalabash.core.XProcRuntime;
import com.xmlcalabash.io.ReadablePipe;
import com.xmlcalabash.io.WritablePipe;
import com.xmlcalabash.model.RuntimeValue;
import net.sf.saxon.s9api.QName;
import net.sf.saxon.s9api.SaxonApiException;
import net.sf.saxon.s9api.XdmNode;
import net.sf.saxon.s9api.XPathCompiler;
import net.sf.saxon.s9api.XPathExecutable;
import net.sf.saxon.trans.XPathException;
import net.sf.saxon.sxpath.XPathExpression;
import net.sf.saxon.sxpath.XPathDynamicContext;
import net.sf.saxon.expr.XPathContext;
import net.sf.saxon.om.Item;
import net.sf.saxon.om.SequenceIterator;
import net.sf.saxon.value.BooleanValue;
import com.xmlcalabash.runtime.XAtomicStep;
import com.xmlcalabash.util.DocumentSequenceIterator;
/**
*
* @author ndw
*/
public class SplitSequence extends DefaultStep {
private static final QName _test = new QName("", "test");
private static final QName _initial_only = new QName("", "initial-only");
private ReadablePipe source = null;
private WritablePipe matched = null;
private WritablePipe notMatched = null;
private boolean initialOnly = false;
/** Creates a new instance of SplitSequence */
public SplitSequence(XProcRuntime runtime, XAtomicStep step) {
super(runtime,step);
}
public void setInput(String port, ReadablePipe pipe) {
source = pipe;
}
public void setOutput(String port, WritablePipe pipe) {
if ("matched".equals(port)) {
matched = pipe;
} else {
notMatched = pipe;
}
}
public void reset() {
source.resetReader();
matched.resetWriter();
notMatched.resetWriter();
}
public void run() throws SaxonApiException {
super.run();
RuntimeValue test = getOption(_test);
initialOnly = getOption(_initial_only, false);
boolean stillOk = true;
int count = 0;
while (source.moreDocuments()) {
count++;
source.read();
}
source.resetReader();
DocumentSequenceIterator xsi = new DocumentSequenceIterator(); // See below
xsi.setLast(count);
XPathCompiler xcomp = runtime.getProcessor().newXPathCompiler();
xcomp.setBaseURI(step.getNode().getBaseURI());
for (String prefix : test.getNamespaceBindings().keySet()) {
xcomp.declareNamespace(prefix, test.getNamespaceBindings().get(prefix));
}
XPathExecutable xexec = xcomp.compile(test.getString());
// From Michael Kay: http://markmail.org/message/vkb2vaq2miylgndu
//
// Underneath the s9api XPathExecutable is a net.sf.saxon.sxpath.XPathExpression.
XPathExpression xexpr = xexec.getUnderlyingExpression();
int pos = 0;
while (source.moreDocuments()) {
XdmNode doc = source.read();
pos++;
Item item = null;
try {
// Call createDynamicContext() on this to get an XPathDynamicContext object;
XPathDynamicContext xdc = xexpr.createDynamicContext(doc.getUnderlyingNode());
// call getXPathContextObject() on that to get the underlying XPathContext.
XPathContext xc = xdc.getXPathContextObject();
// Then call XPathContext.setCurrentIterator()
// to supply a SequenceIterator whose current() and position() methods return
// the context item and position respectively. If there's any risk that the
// expression will call the last() method, then it's simplest to make your
// iterator's getProperties() return LAST_POSITION_FINDER, and implement the
// LastPositionFinder interface, in which case last() will be implemented by
// calling the iterator's getLastPosition() method. (Otherwise last() is
// implemented by calling getAnother() to clone the iterator and calling next()
// on the clone until the end of the sequence is reached).
xsi.setPosition(pos);
xsi.setItem(doc.getUnderlyingNode());
xc.setCurrentIterator(xsi);
// Then evaluate the expression by calling iterate() on the
// net.sf.saxon.sxpath.XPathExpression object.
SequenceIterator<?> results = xexpr.iterate(xdc);
// FIXME: What if the expression returns a sequence?
item = results.next();
} catch (XPathException xe) {
throw new XProcException(xe);
}
//
// Good luck!
//
// FIXME: Compute effective boolean value in a more robust way
boolean pass = false;
if (item instanceof BooleanValue) {
pass = ((BooleanValue) item).getBooleanValue();
} else {
pass = (item != null);
}
stillOk = stillOk && pass;
if (pass && (!initialOnly || stillOk)) {
matched.write(doc);
} else {
notMatched.write(doc);
}
}
}
}