package com.xmlcalabash.runtime;
import com.xmlcalabash.io.ReadablePipe;
import com.xmlcalabash.io.DocumentSequence;
import com.xmlcalabash.core.XProcRuntime;
import com.xmlcalabash.core.XProcException;
import com.xmlcalabash.util.MessageFormatter;
import com.xmlcalabash.util.S9apiUtils;
import com.xmlcalabash.model.NamespaceBinding;
import com.xmlcalabash.model.Step;
import com.xmlcalabash.model.RuntimeValue;
import java.util.Iterator;
import java.util.Hashtable;
import org.slf4j.Logger;
import net.sf.saxon.s9api.*;
import net.sf.saxon.sxpath.IndependentContext;
import org.slf4j.LoggerFactory;
/**
* 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://runtime.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.
*
* 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.
*
* Created by IntelliJ IDEA.
* User: ndw
* Date: Oct 10, 2008
* Time: 10:13:58 PM
* To change this template use File | Settings | File Templates.
*/
public class XSelect implements ReadablePipe {
protected Logger logger = LoggerFactory.getLogger(XSelect.class);
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 XStep forStep = null;
/** Creates a new instance of Select */
public XSelect(XProcRuntime runtime, XStep forStep, ReadablePipe readFrom, String xpathExpr, XdmNode context) {
source = readFrom;
select = xpathExpr;
this.runtime = runtime;
this.context = context;
documents = new DocumentSequence(runtime);
this.forStep = forStep;
}
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());
IndependentContext icontext = (IndependentContext) xcomp.getUnderlyingStaticContext();
Hashtable<QName, RuntimeValue> inScopeOptions = new Hashtable<QName, RuntimeValue> ();
try {
inScopeOptions = ((XCompoundStep) forStep).getInScopeOptions();
} catch (ClassCastException cce) {
// FIXME: Surely there's a better way to do this!!!
}
Hashtable<QName, RuntimeValue> boundOpts = new Hashtable<QName, RuntimeValue> ();
for (QName name : inScopeOptions.keySet()) {
RuntimeValue v = inScopeOptions.get(name);
if (v.initialized()) {
boundOpts.put(name, v);
}
}
for (QName varname : boundOpts.keySet()) {
xcomp.declareVariable(varname);
}
for (String prefix : bindings.getNamespaceBindings().keySet()) {
xcomp.declareNamespace(prefix, bindings.getNamespaceBindings().get(prefix));
}
XPathExecutable xexec = xcomp.compile(select);
selector = xexec.load();
for (QName varname : boundOpts.keySet()) {
XdmAtomicValue avalue = boundOpts.get(varname).getUntypedAtomic(runtime);
selector.setVariable(varname,avalue);
}
} catch (SaxonApiException sae) {
if (S9apiUtils.xpathSyntaxError(sae)) {
throw XProcException.dynamicError(23, context, "Invalid XPath expression: '" + select + "'.");
} else {
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;
if ((node.getNodeKind() != XdmNodeKind.ELEMENT)
&& (node.getNodeKind() != XdmNodeKind.DOCUMENT)) {
throw XProcException.dynamicError(16);
}
} catch (ClassCastException cce) {
throw XProcException.dynamicError(16);
}
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;
source.resetReader();
documents.reset();
initialized = false;
}
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;
}
public String toString() {
return "xselect " + documents;
}
}