/*
* Select.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.io;
import com.xmlcalabash.util.MessageFormatter;
import net.sf.saxon.s9api.*;
import java.util.Iterator;
import com.xmlcalabash.core.XProcException;
import com.xmlcalabash.core.XProcRuntime;
import com.xmlcalabash.model.NamespaceBinding;
import com.xmlcalabash.model.Step;
import com.xmlcalabash.util.S9apiUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
*
* Ideally, I'd like this code to perform the selections in a lazy fashion, but that's
* hard because it has to be possible to answer questions about how many documents
* will be returned. So for now, I'm just doing it all up front.
*
* @author ndw
*/
public class Select implements ReadablePipe {
private ReadablePipe source = null;
private String select = null;
private XdmNode context = null;
private DocumentSequence documents = null;
private XPathSelector selector = null;
private XProcRuntime runtime = null;
private boolean initialized = false;
private int docindex = 0;
private Step reader = null;
private Logger logger = LoggerFactory.getLogger(Select.class);
/** Creates a new instance of Select */
public Select(XProcRuntime runtime, ReadablePipe readFrom, String xpathExpr, XdmNode xpathContext) {
source = readFrom;
select = xpathExpr;
context = xpathContext;
this.runtime = runtime;
documents = new DocumentSequence(runtime);
}
public void canReadSequence(boolean sequence) {
// nop; always true
}
public boolean readSequence() {
return true;
}
private void readSource() {
initialized = true;
try {
NamespaceBinding bindings = new NamespaceBinding(runtime,context);
XPathCompiler xcomp = runtime.getProcessor().newXPathCompiler();
xcomp.setBaseURI(context.getBaseURI());
for (String prefix : bindings.getNamespaceBindings().keySet()) {
xcomp.declareNamespace(prefix, bindings.getNamespaceBindings().get(prefix));
}
XPathExecutable xexec = xcomp.compile(select);
selector = xexec.load();
// FIXME: Set getVariables
} catch (SaxonApiException sae) {
throw new XProcException(sae);
}
while (source.moreDocuments()) {
// Ok, time to go looking for things to select from.
try {
XdmNode doc = source.read();
if (reader != null) {
logger.trace(MessageFormatter.nodeMessage(reader.getNode(),
reader.getName() + " select read '" + (doc == null ? "null" : doc.getBaseURI()) + "' from " + source));
}
selector.setContextItem(doc);
Iterator<XdmItem> iter = selector.iterator();
while (iter.hasNext()) {
XdmItem item = iter.next();
XdmNode node = null;
try {
node = (XdmNode) item;
} catch (ClassCastException cce) {
throw new XProcException (context, "Select matched non-node!?");
}
XdmDestination dest = new XdmDestination();
S9apiUtils.writeXdmValue(runtime, node, dest, node.getBaseURI());
XdmNode sdoc = dest.getXdmNode();
if (reader != null) {
logger.trace(MessageFormatter.nodeMessage(reader.getNode(),
reader.getName() + " select wrote '" + (sdoc == null ? "null" : sdoc.getBaseURI()) + "' to " + documents));
}
documents.add(sdoc);
}
} catch (SaxonApiException sae) {
throw new XProcException(sae);
}
}
}
public void resetReader() {
docindex = 0;
}
public boolean moreDocuments() {
if (!initialized) {
readSource();
}
return docindex < documents.size();
}
public boolean closed() {
return true;
}
public int documentCount() {
if (!initialized) {
readSource();
}
return documents.size();
}
public DocumentSequence documents() {
return documents;
}
public void setReader(Step step) {
reader = step;
}
public XdmNode read () throws SaxonApiException {
if (!initialized) {
readSource();
}
XdmNode doc = null;
if (moreDocuments()) {
doc = documents.get(docindex++);
}
if (reader != null) {
logger.trace(MessageFormatter.nodeMessage(reader.getNode(),
reader.getName() + " read '" + (doc == null ? "null" : doc.getBaseURI()) + "' from " + this));
}
return doc;
}
}