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The XSLT and XQuery Processor
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Copyright (c) 2015 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.event.SequenceReceiver;
import net.sf.saxon.expr.*;
import net.sf.saxon.expr.parser.*;
import net.sf.saxon.om.NameChecker;
import net.sf.saxon.om.NoNamespaceName;
import net.sf.saxon.om.NodeName;
import net.sf.saxon.om.StandardNames;
import net.sf.saxon.pattern.NodeKindTest;
import net.sf.saxon.trace.ExpressionPresenter;
import net.sf.saxon.trans.Err;
import net.sf.saxon.trans.XPathException;
import net.sf.saxon.type.ItemType;
import net.sf.saxon.value.AnyURIValue;
import net.sf.saxon.value.AtomicValue;
import net.sf.saxon.value.SequenceType;
import net.sf.saxon.value.Whitespace;
/**
* An xsl:processing-instruction element in the stylesheet, or a processing-instruction
* constructor in a query
*/
public class ProcessingInstruction extends SimpleNodeConstructor {
private Operand nameOp;
/**
* Create an xsl:processing-instruction instruction
*
* @param name the expression used to compute the name of the generated
* processing-instruction
*/
public ProcessingInstruction(Expression name) {
nameOp = new Operand(this, name, OperandRole.SINGLE_ATOMIC);
}
public Expression getNameExp() {
return nameOp.getChildExpression();
}
public void setNameExp(Expression nameExp) {
nameOp.setChildExpression(nameExp);
}
@Override
public Iterable operands() {
return operandList(selectOp, nameOp);
}
/**
* Get the name of this instruction for diagnostic and tracing purposes
*
* @return the string "xsl:processing-instruction"
*/
public int getInstructionNameCode() {
return StandardNames.XSL_PROCESSING_INSTRUCTION;
}
/*@NotNull*/
public ItemType getItemType() {
return NodeKindTest.PROCESSING_INSTRUCTION;
}
public int getCardinality() {
return StaticProperty.EXACTLY_ONE;
}
/**
* Copy an expression. This makes a deep copy.
*
* @return the copy of the original expression
*/
/*@NotNull*/
public Expression copy() {
ProcessingInstruction exp = new ProcessingInstruction(getNameExp().copy());
ExpressionTool.copyLocationInfo(this, exp);
exp.setSelect(getSelect().copy());
return exp;
}
public void localTypeCheck(ExpressionVisitor visitor, ContextItemStaticInfo contextItemType) throws XPathException {
StaticContext env = visitor.getStaticContext();
nameOp.typeCheck(visitor, contextItemType);
RoleDiagnostic role = new RoleDiagnostic(RoleDiagnostic.INSTRUCTION, "processing-instruction/name", 0);
// See bug 2110. XQuery does not use the function conversion rules here, and disallows xs:anyURI.
// In XSLT the name is an AVT so we automatically get a string; in XQuery we'll use the standard
// mechanism to get an atomic value, and then check the type "by hand" at run time.
setNameExp(TypeChecker.staticTypeCheck(getNameExp(), SequenceType.SINGLE_ATOMIC, false, role, visitor));
adoptChildExpression(getNameExp());
// Do early checking of name if known statically
if (getNameExp() instanceof Literal) {
String s = ((Literal) getNameExp()).getValue().getStringValue();
checkName(Whitespace.trim(s), env.makeEarlyEvaluationContext());
}
// Do early checking of content if known statically
if (getSelect() instanceof Literal) {
String s = ((Literal) getSelect()).getValue().getStringValue();
String s2 = checkContent(s, env.makeEarlyEvaluationContext());
if (!s2.equals(s)) {
setSelect(new StringLiteral(s2));
}
}
}
public int getDependencies() {
return getNameExp().getDependencies() | super.getDependencies();
}
/**
* Offer promotion for subexpressions. The offer will be accepted if the subexpression
* is not dependent on the factors (e.g. the context item) identified in the PromotionOffer.
* By default the offer is not accepted - this is appropriate in the case of simple expressions
* such as constant values and variable references where promotion would give no performance
* advantage. This method is always called at compile time.
*
* @param offer details of the offer, for example the offer to move
* expressions that don't depend on the context to an outer level in
* the containing expression
* @throws XPathException if any error is detected
*/
protected void promoteChildren(PromotionOffer offer) throws XPathException {
setNameExp(doPromotion(getNameExp(), offer));
super.promoteChildren(offer);
}
/**
* Process the value of the node, to create the new node.
*
* @param value the string value of the new node
* @param context the dynamic evaluation context
* @throws XPathException
*/
public void processValue(CharSequence value, XPathContext context) throws XPathException {
String expandedName = evaluateName(context);
if (expandedName != null) {
String data = checkContent(value.toString(), context);
SequenceReceiver out = context.getReceiver();
out.processingInstruction(expandedName, data, getLocation(), 0);
}
}
/**
* Check the content of the node, and adjust it if necessary
*
* @param data the supplied content
* @return the original content, unless adjustments are needed
* @throws XPathException if the content is invalid
*/
protected String checkContent(String data, XPathContext context) throws XPathException {
if (isXSLT()) {
return checkContentXSLT(data);
} else {
try {
return checkContentXQuery(data);
} catch (XPathException err) {
err.setXPathContext(context);
err.setLocation(getLocation());
throw err;
}
}
}
/**
* Check the content of the node, and adjust it if necessary, using the XSLT rules
*
* @param data the supplied content
* @return the original content, unless adjustments are needed
*/
public static String checkContentXSLT(String data) {
int hh;
while ((hh = data.indexOf("?>")) >= 0) {
data = data.substring(0, hh + 1) + ' ' + data.substring(hh + 1);
}
return Whitespace.removeLeadingWhitespace(data).toString();
}
/**
* Check the content of the node, and adjust it if necessary, using the XQuery rules
*
* @param data the supplied content
* @return the original content, unless adjustments are needed
* @throws XPathException if the content is invalid
*/
public static String checkContentXQuery(String data) throws XPathException {
if (data.contains("?>")) {
throw new XPathException("Invalid characters (?>) in processing instruction", "XQDY0026");
}
return Whitespace.removeLeadingWhitespace(data).toString();
}
public NodeName evaluateNodeName(XPathContext context) throws XPathException {
String expandedName = evaluateName(context);
return new NoNamespaceName(expandedName);
}
/**
* Evaluate the name of the processing instruction.
*
* @param context the dynamic evaluation context
* @return the name of the processing instruction (an NCName), or null, indicating an invalid name
* @throws XPathException if evaluation fails, or if the recoverable error is treated as fatal
*/
private String evaluateName(XPathContext context) throws XPathException {
AtomicValue av = (AtomicValue) getNameExp().evaluateItem(context);
if (av instanceof net.sf.saxon.value.StringValue && !(av instanceof AnyURIValue)) {
// Always true under XSLT
String expandedName = Whitespace.trim(av.getStringValueCS());
checkName(expandedName, context);
return expandedName;
} else {
XPathException e = new XPathException("Processing instruction name is not a string");
e.setXPathContext(context);
e.setErrorCode("XPTY0004");
throw dynamicError(getLocation(), e, context);
}
}
private void checkName(String expandedName, XPathContext context) throws XPathException {
if (!NameChecker.isValidNCName(expandedName)) {
XPathException e = new XPathException("Processing instruction name " + Err.wrap(expandedName) + " is not a valid NCName");
e.setXPathContext(context);
e.setErrorCode(isXSLT() ? "XTDE0890" : "XQDY0041");
throw dynamicError(getLocation(), e, context);
}
if (expandedName.equalsIgnoreCase("xml")) {
XPathException e = new XPathException("Processing instructions cannot be named 'xml' in any combination of upper/lower case");
e.setXPathContext(context);
e.setErrorCode(isXSLT() ? "XTDE0890" : "XQDY0064");
throw dynamicError(getLocation(), e, context);
}
}
/**
* Diagnostic print of expression structure. The abstract expression tree
* is written to the supplied output destination.
*/
public void export(ExpressionPresenter out) {
out.startElement("procInst", this);
out.setChildRole("name");
getNameExp().export(out);
out.setChildRole("select");
getSelect().export(out);
out.endElement();
}
}
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