net.sf.saxon.expr.instruct.Message Maven / Gradle / Ivy
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Copyright (c) 2013 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.expr.instruct;
import net.sf.saxon.Configuration;
import net.sf.saxon.Controller;
import net.sf.saxon.event.*;
import net.sf.saxon.expr.Expression;
import net.sf.saxon.expr.StaticProperty;
import net.sf.saxon.expr.XPathContext;
import net.sf.saxon.expr.parser.ExpressionVisitor;
import net.sf.saxon.expr.parser.PromotionOffer;
import net.sf.saxon.lib.SerializerFactory;
import net.sf.saxon.lib.StandardErrorListener;
import net.sf.saxon.om.*;
import net.sf.saxon.trace.ExpressionPresenter;
import net.sf.saxon.trans.XPathException;
import net.sf.saxon.type.*;
import javax.xml.transform.OutputKeys;
import java.util.Arrays;
import java.util.Iterator;
import java.util.List;
import java.util.Properties;
/**
* An xsl:message element in the stylesheet.
*/
public class Message extends Instruction {
/*@NotNull*/ private Expression terminate;
/*@NotNull*/ private Expression select;
private Expression errorCode;
private NamespaceResolver nsResolver;
private boolean isAssert;
/**
* Create an xsl:message instruction
*
* @param select the expression that constructs the message (composite of the select attribute
* and the contained sequence constructor)
* @param terminate expression that calculates terminate = yes or no.
*/
public Message(/*@NotNull*/ Expression select, /*@NotNull*/ Expression terminate, Expression errorCode) {
this.terminate = terminate;
this.select = select;
this.errorCode = errorCode;
adoptChildExpression(terminate);
adoptChildExpression(select);
}
/**
* Say whether this instruction is implementing xsl:message or xsl:assert
* @param isAssert true if this is xsl:assert; false if it is xsl:message
*/
public void setIsAssert(boolean isAssert) {
this.isAssert = isAssert;
}
/**
* Set a namespace resolver for resolving any namespace prefix appearing in the value of the error-code
* attribute
* @param resolver
*/
public void setNamespaceResolver(NamespaceResolver resolver) {
this.nsResolver = resolver;
}
/**
* Simplify an expression. This performs any static optimization (by rewriting the expression
* as a different expression). The default implementation does nothing.
*
* @param visitor an expression visitor
* @return the simplified expression
* @throws net.sf.saxon.trans.XPathException
* if an error is discovered during expression rewriting
*/
/*@NotNull*/
public Expression simplify(ExpressionVisitor visitor) throws XPathException {
select = visitor.simplify(select);
terminate = visitor.simplify(terminate);
errorCode = visitor.simplify(errorCode);
return this;
}
/*@NotNull*/
public Expression typeCheck(ExpressionVisitor visitor, ExpressionVisitor.ContextItemType contextItemType) throws XPathException {
select = visitor.typeCheck(select, contextItemType);
adoptChildExpression(select);
terminate = visitor.typeCheck(terminate, contextItemType);
adoptChildExpression(terminate);
errorCode = visitor.typeCheck(errorCode, contextItemType);
adoptChildExpression(errorCode);
return this;
}
/*@NotNull*/
public Expression optimize(ExpressionVisitor visitor, ExpressionVisitor.ContextItemType contextItemType) throws XPathException {
select = visitor.optimize(select, contextItemType);
adoptChildExpression(select);
terminate = visitor.optimize(terminate, contextItemType);
adoptChildExpression(terminate);
errorCode = visitor.optimize(errorCode, contextItemType);
adoptChildExpression(errorCode);
return this;
}
/**
* Copy an expression. This makes a deep copy.
*
* @return the copy of the original expression
*/
/*@NotNull*/
public Expression copy() {
return new Message(select.copy(), terminate.copy(), errorCode.copy());
}
/**
* Get the name of this instruction for diagnostic and tracing purposes
*/
public int getInstructionNameCode() {
return (isAssert ? StandardNames.XSL_ASSERT : StandardNames.XSL_MESSAGE);
}
/**
* Get the item type. To avoid spurious compile-time type errors, we falsely declare that the
* instruction can return anything
*
* @param th the type hierarchy cache
* @return AnyItemType
*/
/*@NotNull*/
public ItemType getItemType(TypeHierarchy th) {
return AnyItemType.getInstance();
}
/**
* Get the static cardinality. To avoid spurious compile-time type errors, we falsely declare that the
* instruction returns zero or one items - this is always acceptable
*
* @return zero or one
*/
public int getCardinality() {
return StaticProperty.ALLOWS_ZERO_OR_ONE;
}
/**
* Determine whether this instruction creates new nodes.
* This implementation returns true.
*/
public final boolean createsNewNodes() {
return true;
}
/**
* Handle promotion offers, that is, non-local tree rewrites.
*
* @param offer The type of rewrite being offered
* @throws XPathException
*/
protected void promoteInst(PromotionOffer offer) throws XPathException {
select = doPromotion(select, offer);
terminate = doPromotion(terminate, offer);
errorCode = doPromotion(errorCode, offer);
}
/**
* Get all the XPath expressions associated with this instruction
* (in XSLT terms, the expression present on attributes of the instruction,
* as distinct from the child instructions in a sequence construction)
*/
/*@NotNull*/
public Iterator iterateSubExpressions() {
Expression[] children = new Expression[]{select, terminate, errorCode};
return Arrays.asList(children).iterator();
}
/**
* Replace one subexpression by a replacement subexpression
*
* @param original the original subexpression
* @param replacement the replacement subexpression
* @return true if the original subexpression is found
*/
public boolean replaceSubExpression(Expression original, Expression replacement) {
boolean found = false;
if (select == original) {
select = replacement;
found = true;
}
if (terminate == original) {
terminate = replacement;
found = true;
}
if (errorCode == original) {
errorCode = replacement;
found = true;
}
return found;
}
public TailCall processLeavingTail(XPathContext context) throws XPathException {
Controller controller = context.getController();
assert controller != null;
Receiver emitter = controller.getMessageEmitter();
if (emitter != null) {
//noinspection SynchronizationOnLocalVariableOrMethodParameter
synchronized (emitter) {
// In Saxon-EE, multithreading can cause different messages to be entangled unless we synchronize.
SequenceReceiver rec = new TreeReceiver(emitter);
rec = new AttributeMasker(rec);
SequenceReceiver saved = context.getReceiver();
Properties props = new Properties();
props.setProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
SerializerFactory sf = context.getConfiguration().getSerializerFactory();
PipelineConfiguration pipe = controller.makePipelineConfiguration();
pipe.setHostLanguage(Configuration.XSLT);
Receiver receiver = sf.getReceiver(rec, pipe, props);
context.changeOutputDestination(receiver, null);
boolean abort = false;
String term = terminate.evaluateAsString(context).toString();
if (term.equals("no")) {
// no action
} else if (term.equals("yes")) {
abort = true;
} else {
XPathException e = new XPathException("The terminate attribute of xsl:message must be 'yes' or 'no'");
e.setXPathContext(context);
e.setErrorCode("XTDE0030");
throw e;
}
rec.startDocument(abort ? ReceiverOptions.TERMINATE : 0);
SequenceIterator iter = select.iterate(context);
while (true) {
Item item = iter.next();
if (item == null) {
break;
}
rec.append(item, locationId, NodeInfo.ALL_NAMESPACES);
}
rec.endDocument();
context.setReceiver(saved);
if (abort) {
TerminationException te = new TerminationException(
"Processing terminated by " + StandardErrorListener.getInstructionName(this) +
" at line " + getLineNumber() +
" in " + StandardErrorListener.abbreviatePath(getSystemId()));
try {
String code = errorCode.evaluateAsString(context).toString();
StructuredQName errorCode = StructuredQName.fromLexicalQName(
code, false, true, context.getConfiguration().getNameChecker(), nsResolver);
te.setErrorCodeQName(errorCode);
te.setLocator(this);
} catch (XPathException err) {
// no action, ignore the error
}
throw te;
}
return null;
}
} else {
return null;
}
}
/**
* Diagnostic print of expression structure. The abstract expression tree
* is written to the supplied output destination.
*/
public void explain(ExpressionPresenter out) {
out.startElement("xslMessage");
out.endElement();
}
private static class AttributeMasker extends ProxyReceiver {
private boolean contentStarted = true;
public AttributeMasker(SequenceReceiver next) {
super(next);
}
public void startElement(NodeName nameCode, SchemaType typeCode, int locationId, int properties) throws XPathException {
contentStarted = false;
super.startElement(nameCode, typeCode, locationId, properties);
}
public void startContent() throws XPathException {
contentStarted = true;
super.startContent();
}
public void attribute(NodeName attributeName, SimpleType typeCode, CharSequence value, int locationId, int properties)
throws XPathException {
if (contentStarted) {
String attName = attributeName.getDisplayName();
processingInstruction("attribute", "name=\"" + attName + "\" value=\"" + value + "\"", 0, 0);
} else {
super.attribute(attributeName, typeCode, value, locationId, properties);
}
}
public void namespace(NamespaceBinding namespaceBinding, int properties) throws XPathException {
if (contentStarted) {
String prefix = namespaceBinding.getPrefix();
String uri = namespaceBinding.getURI();
processingInstruction("namespace", "prefix=\"" + prefix + "\" uri=\"" + uri + "\"", 0, 0);
} else {
super.namespace(namespaceBinding, properties);
}
}
public void append(Item item, int locationId, int copyNamespaces) throws XPathException {
if (item instanceof NodeInfo) {
int kind = ((NodeInfo) item).getNodeKind();
if (kind == Type.ATTRIBUTE || kind == Type.NAMESPACE) {
((NodeInfo) item).copy(this, 0, 0);
return;
}
}
((SequenceReceiver) nextReceiver).append(item, locationId, copyNamespaces);
}
}
}
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