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////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Copyright (c) 2018-2023 Saxonica Limited
// This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0.
// If a copy of the MPL was not distributed with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
// This Source Code Form is "Incompatible With Secondary Licenses", as defined by the Mozilla Public License, v. 2.0.
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
package net.sf.saxon.functions;
import net.sf.saxon.Configuration;
import net.sf.saxon.Controller;
import net.sf.saxon.Version;
import net.sf.saxon.event.Builder;
import net.sf.saxon.event.ProxyReceiver;
import net.sf.saxon.event.Receiver;
import net.sf.saxon.event.Sender;
import net.sf.saxon.expr.Callable;
import net.sf.saxon.expr.PackageData;
import net.sf.saxon.expr.XPathContext;
import net.sf.saxon.lib.ParseOptions;
import net.sf.saxon.lib.Validation;
import net.sf.saxon.om.*;
import net.sf.saxon.resource.ActiveSAXSource;
import net.sf.saxon.s9api.Location;
import net.sf.saxon.style.StylesheetPackage;
import net.sf.saxon.trans.XPathException;
import net.sf.saxon.transpile.CSharp;
import net.sf.saxon.transpile.CSharpReplaceBody;
import net.sf.saxon.tree.tiny.TinyBuilder;
import net.sf.saxon.type.SchemaType;
import net.sf.saxon.value.EmptySequence;
import net.sf.saxon.value.StringValue;
import org.xml.sax.InputSource;
import org.xml.sax.XMLReader;
import javax.xml.transform.sax.SAXSource;
import java.io.StringReader;
import java.util.ArrayList;
import java.util.List;
public class ParseXmlFragment extends SystemFunction implements Callable {
/**
* Evaluate the expression
*
* @param context the dynamic evaluation context
* @param arguments the values of the arguments, supplied as SequenceIterators
* @return the result of the evaluation, in the form of a SequenceIterator
* @throws net.sf.saxon.trans.XPathException
* if a dynamic error occurs during the evaluation of the expression
*/
@Override
@CSharpReplaceBody(code="return Saxon.Hej.value.EmptySequence.getInstance(); // TODO: implement me!")
public Sequence call(XPathContext context, Sequence[] arguments) throws XPathException {
StringValue input = (StringValue) arguments[0].head();
if (input == null) {
return EmptySequence.getInstance();
} else {
return evalParseXml(input, context);
}
}
private NodeInfo evalParseXml(StringValue inputArg, XPathContext context) throws XPathException {
NodeInfo node = null;
final String baseURI = getStaticBaseUriString();
ParseXml.RetentiveErrorHandler errorHandler = new ParseXml.RetentiveErrorHandler();
int attempt = 0;
while (attempt++ < 3) {
try {
Controller controller = context.getController();
if (controller == null) {
throw new XPathException("parse-xml-fragment() function is not available in this environment");
}
Configuration configuration = controller.getConfiguration();
final StringReader fragmentReader = new StringReader(inputArg.getStringValue());
String skeleton = "]>\n&e; ";
StringReader skeletonReader = new StringReader(skeleton);
InputSource is = new InputSource(skeletonReader);
is.setSystemId(baseURI);
SAXSource source = new SAXSource(is);
XMLReader reader;
if (attempt == 1) {
reader = configuration.getSourceParser();
if (reader.getEntityResolver() != null) {
continue;
// we don't want to overwrite the existing EntityResolver; try again
// with a clean parser
}
} else {
reader = Version.platform.loadParserForXmlFragments();
}
ActiveSAXSource.configureParser(reader);
source.setXMLReader(reader);
source.setSystemId(baseURI);
Builder b = controller.makeBuilder();
b.setDurability(Durability.TEMPORARY);
if (b instanceof TinyBuilder) {
((TinyBuilder) b).setStatistics(controller.getConfiguration().getTreeStatistics().FN_PARSE_STATISTICS);
}
Receiver s = b;
ParseOptions options = new ParseOptions()
.withSchemaValidationMode(Validation.SKIP)
.withDTDValidationMode(Validation.SKIP);
List safetyCheck = new ArrayList<>();
reader.setEntityResolver((publicId, systemId) -> {
if ("http://www.saxonica.com/parse-xml-fragment/actual.xml".equals(systemId)) {
safetyCheck.add(true);
InputSource is1 = new InputSource(fragmentReader);
is1.setSystemId(baseURI);
return is1;
} else {
return null;
}
});
PackageData pd = getRetainedStaticContext().getPackageData();
if (pd instanceof StylesheetPackage) {
options = options.withSpaceStrippingRule(((StylesheetPackage) pd).getSpaceStrippingRule());
if (((StylesheetPackage) pd).isStripsTypeAnnotations()) {
s = configuration.getAnnotationStripper(s);
}
} else {
options = options.withSpaceStrippingRule(IgnorableSpaceStrippingRule.getInstance());
}
options = options.withErrorHandler(errorHandler);
s.setPipelineConfiguration(b.getPipelineConfiguration());
options = options.withFilter(CSharp.methodRef(OuterElementStripper::new));
try {
Sender.send(source, s, options);
} catch (XPathException e) {
// this might be because the EntityResolver wasn't called - see bug 4127
if (safetyCheck.isEmpty()) {
// This means our entity resolver wasn't called. Make one more try, using the
// built-in platform default parser; then give up.
if (attempt == 2) {
XPathException xe = new XPathException("The configured XML parser cannot be used by fn:parse-xml-fragment(), because it ignores the supplied EntityResolver", "FODC0006");
errorHandler.captureRetainedErrors(xe);
xe.maybeSetContext(context);
throw xe;
} else {
continue;
}
} else {
throw e;
}
}
node = b.getCurrentRoot();
b.reset();
} catch (XPathException err) {
XPathException xe = new XPathException("First argument to parse-xml-fragment() is not a well-formed and namespace-well-formed XML fragment. XML parser reported: " +
err.getMessage(), "FODC0006");
errorHandler.captureRetainedErrors(xe);
xe.maybeSetContext(context);
throw xe;
}
}
return node;
}
/**
* Filter to remove the element wrapper added to the document to satisfy the XML parser
*/
private static class OuterElementStripper extends ProxyReceiver {
public OuterElementStripper(Receiver next) {
super(next);
}
private int level = 0;
private final boolean suppressStartContent = false;
/**
* Notify the start of an element
*/
@Override
public void startElement(NodeName elemName, SchemaType type,
AttributeMap attributes, NamespaceMap namespaces,
Location location, int properties) throws XPathException {
if (level++ > 0) {
super.startElement(elemName, type, attributes, namespaces, location, properties);
}
}
/**
* End of element
*/
@Override
public void endElement() throws XPathException {
if (--level > 0) {
super.endElement();
}
}
}
}
// Copyright (c) 2012-2023 Saxonica Limited