package net.sf.saxon.instruct;
import net.sf.saxon.Err;
import net.sf.saxon.event.ReceiverOptions;
import net.sf.saxon.event.SequenceReceiver;
import net.sf.saxon.expr.*;
import net.sf.saxon.om.*;
import net.sf.saxon.pattern.NodeKindTest;
import net.sf.saxon.trace.ExpressionPresenter;
import net.sf.saxon.trans.XPathException;
import net.sf.saxon.type.*;
import net.sf.saxon.value.*;
import java.util.ArrayList;
import java.util.Iterator;
/**
* An instruction derived from an xsl:attribute element in stylesheet, or from
* an attribute constructor in XQuery, in cases where the attribute name is not known
* statically
*/
public final class ComputedAttribute extends SimpleNodeConstructor {
private Expression attributeName;
private Expression namespace = null;
private NamespaceResolver nsContext;
private SimpleType schemaType;
private int annotation;
private int validationAction;
private boolean allowNameAsQName;
private int options;
/**
* Construct an Attribute instruction
* @param attributeName An expression to calculate the attribute name
* @param namespace An expression to calculate the attribute namespace
* @param nsContext a NamespaceContext object containing the static namespace context of the
* stylesheet instruction
* @param validationAction e.g. validation=strict, lax, strip, preserve
* @param schemaType Type against which the attribute must be validated. This must not be a namespace-sensitive
* type; it is the caller's responsibility to check this.
* @param annotation Integer code identifying the type named in the <code>type</code> attribute
* @param allowNameAsQName true if the attributeName expression is allowed to evaluate to a value
* of type xs:QName (true in XQuery, false in XSLT)
*/
public ComputedAttribute (Expression attributeName,
Expression namespace,
NamespaceResolver nsContext,
int validationAction,
SimpleType schemaType,
int annotation,
boolean allowNameAsQName) {
this.attributeName = attributeName;
this.namespace = namespace;
this.nsContext = nsContext;
this.schemaType = schemaType;
if (annotation == -1) {
this.annotation = StandardNames.XS_UNTYPED_ATOMIC;
} else {
this.annotation = annotation;
}
this.validationAction = validationAction;
options = 0;
this.allowNameAsQName = allowNameAsQName;
adoptChildExpression(attributeName);
adoptChildExpression(namespace);
}
/**
* Indicate that two attributes with the same name are not acceptable.
* (This option is set in XQuery, but not in XSLT)
*/
public void setRejectDuplicates() {
options |= ReceiverOptions.REJECT_DUPLICATES;
}
/**
* Get the name of this instruction
*/
public int getInstructionNameCode() {
return StandardNames.XSL_ATTRIBUTE;
}
/**
* Get the expression used to compute the name of the attribute
* @return the expression used to compute the name of the attribute
*/
public Expression getNameExpression() {
return attributeName;
}
/**
* Get the expression used to compute the namespace part of the name of the attribute
* @return the expression used to compute the namespace part of the name of the attribute
*/
public Expression getNamespaceExpression() {
return namespace;
}
/**
* Get the namespace resolver used to resolve any prefix in the name of the attribute
* @return the namespace resolver if one has been saved; or null otherwise
*/
public NamespaceResolver getNamespaceResolver() {
return nsContext;
}
/**
* Get the static type of this expression
* @param th the type hierarchy cache
* @return the static type of the item returned by this expression
*/
public ItemType getItemType(TypeHierarchy th) {
return NodeKindTest.ATTRIBUTE;
}
/**
* Get the static cardinality of this expression
* @return the static cardinality (exactly one)
*/
public int getCardinality() {
return StaticProperty.EXACTLY_ONE;
}
/**
* Get the static properties of this expression (other than its type). The result is
* bit-signficant. These properties are used for optimizations. In general, if
* property bit is set, it is true, but if it is unset, the value is unknown.
*
* @return a set of flags indicating static properties of this expression
*/
public int computeSpecialProperties() {
return super.computeSpecialProperties() |
StaticProperty.SINGLE_DOCUMENT_NODESET;
}
public Expression simplify(ExpressionVisitor visitor) throws XPathException {
attributeName = visitor.simplify(attributeName);
namespace = visitor.simplify(namespace);
return super.simplify(visitor);
}
public void localTypeCheck(ExpressionVisitor visitor, ItemType contextItemType) throws XPathException {
StaticContext env = visitor.getStaticContext();
attributeName = visitor.typeCheck(attributeName, contextItemType);
adoptChildExpression(attributeName);
RoleLocator role = new RoleLocator(RoleLocator.INSTRUCTION, "attribute/name", 0, null);
role.setSourceLocator(this);
if (allowNameAsQName) {
// Can only happen in XQuery
attributeName = TypeChecker.staticTypeCheck(attributeName,
SequenceType.SINGLE_ATOMIC, false, role, visitor);
TypeHierarchy th = visitor.getConfiguration().getTypeHierarchy();
ItemType nameItemType = attributeName.getItemType(th);
boolean maybeString = th.relationship(nameItemType, BuiltInAtomicType.STRING) != TypeHierarchy.DISJOINT ||
th.relationship(nameItemType, BuiltInAtomicType.UNTYPED_ATOMIC) != TypeHierarchy.DISJOINT;
boolean maybeQName = th.relationship(nameItemType, BuiltInAtomicType.QNAME) != TypeHierarchy.DISJOINT;
if (!(maybeString || maybeQName)) {
XPathException err = new XPathException(
"The attribute name must be either an xs:string, an xs:QName, or untyped atomic");
err.setErrorCode("XPTY0004");
err.setIsTypeError(true);
err.setLocator(this);
throw err;
}
} else {
attributeName = TypeChecker.staticTypeCheck(attributeName,
SequenceType.SINGLE_STRING, false, role, visitor);
}
if (namespace != null) {
visitor.typeCheck(namespace, contextItemType);
adoptChildExpression(namespace);
role = new RoleLocator(RoleLocator.INSTRUCTION, "attribute/namespace", 0, null);
role.setSourceLocator(this);
namespace = TypeChecker.staticTypeCheck(
namespace, SequenceType.SINGLE_STRING, false, role, visitor);
}
if (Literal.isAtomic(attributeName)) {
// Check we have a valid lexical QName, whose prefix is in scope where necessary
try {
AtomicValue val = (AtomicValue)((Literal)attributeName).getValue();
if (val instanceof StringValue) {
String[] parts = env.getConfiguration().getNameChecker().checkQNameParts(val.getStringValueCS());
if (namespace == null) {
String uri = getNamespaceResolver().getURIForPrefix(parts[0], true);
if (uri == null) {
XPathException se = new XPathException("Prefix " + parts[0] + " has not been declared");
se.setErrorCode("XPST0081");
se.setIsStaticError(true);
throw se;
}
namespace = new StringLiteral(uri);
}
}
} catch (XPathException e) {
e.maybeSetLocation(this);
e.setIsStaticError(true);
throw e;
}
}
// TODO: if the attribute name was a compile-time expression, we could replace this expression
// by a FixedAttribute instruction (ditto for elements)
}
public Expression optimize(ExpressionVisitor visitor, ItemType contextItemType) throws XPathException {
attributeName = visitor.optimize(attributeName, contextItemType);
return super.optimize(visitor, contextItemType);
}
/**
* Copy an expression. This makes a deep copy.
*
* @return the copy of the original expression
*/
public Expression copy() {
ComputedAttribute exp = new ComputedAttribute(
attributeName == null ? null : attributeName.copy(),
namespace == null ? null : namespace.copy(),
nsContext, validationAction, schemaType, annotation, allowNameAsQName);
try {
exp.setSelect(select == null ? null : select.copy(), getExecutable().getConfiguration());
} catch (XPathException err) {
throw new UnsupportedOperationException(err.getMessage());
}
return exp;
}
/**
* Get the subexpressions of this expression
* @return an iterator over the subexpressions
*/
public Iterator iterateSubExpressions() {
ArrayList list = new ArrayList(3);
if (select != null) {
list.add(select);
}
list.add(attributeName);
if (namespace != null) {
list.add(namespace);
}
return list.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 (attributeName == original) {
attributeName = replacement;
found = true;
}
if (namespace == original) {
namespace = replacement;
found = true;
}
return found;
}
/**
* 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
* @exception XPathException if any error is detected
*/
protected void promoteInst(PromotionOffer offer) throws XPathException {
attributeName = doPromotion(attributeName, offer);
if (namespace != null) {
namespace = doPromotion(namespace, offer);
}
super.promoteInst(offer);
}
/**
* Check that any elements and attributes constructed or returned by this expression are acceptable
* in the content model of a given complex type. It's always OK to say yes, since the check will be
* repeated at run-time. The process of checking element and attribute constructors against the content
* model of a complex type also registers the type of content expected of those constructors, so the
* static validation can continue recursively.
*/
public void checkPermittedContents(SchemaType parentType, StaticContext env, boolean whole) throws XPathException {
if (parentType instanceof SimpleType) {
XPathException err = new XPathException("Attributes are not permitted here: the containing element is of simple type " +
parentType.getDescription());
err.setIsTypeError(true);
err.setLocator(this);
throw err;
}
}
/**
* Process this instruction
* @param context the dynamic context of the transformation
* @return a TailCall to be executed by the caller, always null for this instruction
*/
public TailCall processLeavingTail(XPathContext context) throws XPathException
{
int nameCode = evaluateNameCode(context);
if (nameCode == -1) {
return null;
}
SequenceReceiver out = context.getReceiver();
int opt = options;
int ann = annotation;
// we may need to change the namespace prefix if the one we chose is
// already in use with a different namespace URI: this is done behind the scenes
// by the ComplexContentOutputter
CharSequence value = expandChildren(context).toString();
if (schemaType != null) {
// test whether the value actually conforms to the given type
try {
ValidationFailure err = schemaType.validateContent(
value, DummyNamespaceResolver.getInstance(), context.getConfiguration().getNameChecker());
if (err != null) {
ValidationException ve = new ValidationException(
"Attribute value " + Err.wrap(value, Err.VALUE) +
" does not match the required type " +
schemaType.getDescription() + ". " +
err.getMessage());
ve.setErrorCode("XTTE1540");
throw ve;
}
} catch (UnresolvedReferenceException ure) {
throw new ValidationException(ure);
}
} else if (validationAction==Validation.STRICT ||
validationAction==Validation.LAX) {
try {
ann = context.getConfiguration().validateAttribute(nameCode, value, validationAction);
} catch (ValidationException e) {
XPathException err = XPathException.makeXPathException(e);
String errorCode = e.getErrorCodeLocalPart();
if (errorCode == null) {
errorCode = (validationAction==Validation.STRICT ? "XTTE1510" : "XTTE1515");
}
err.setErrorCode(errorCode);
err.setXPathContext(context);
err.setLocator(this);
err.setIsTypeError(true);
throw err;
}
}
if ((nameCode & NamePool.FP_MASK) == StandardNames.XML_ID) {
value = Whitespace.collapseWhitespace(value);
}
try {
out.attribute(nameCode, ann, value, locationId, opt);
} catch (XPathException err) {
throw dynamicError(this, err, context);
}
return null;
}
/**
* Determine the name to be used for the attribute, as an integer name code
* @param context Dynamic evaluation context
* @return the integer name code for the attribute name
* @throws XPathException
*/
public int evaluateNameCode(XPathContext context) throws XPathException {
NamePool pool = context.getNamePool();
Item nameValue = attributeName.evaluateItem(context);
String prefix = null;
String localName;
String uri = null;
if (nameValue instanceof StringValue) {
// this will always be the case in XSLT
CharSequence rawName = nameValue.getStringValueCS();
if (Whitespace.containsWhitespace(rawName)) {
rawName = Whitespace.trim(rawName);
}
try {
String[] parts = context.getConfiguration().getNameChecker().getQNameParts(rawName);
prefix = parts[0];
localName = parts[1];
} catch (QNameException err) {
XPathException err1 = new XPathException("Invalid attribute name: " + rawName, this);
err1.setErrorCode((isXSLT() ? "XTDE0850" : "XQDY0074"));
err1.setXPathContext(context);
throw dynamicError(this, err1, context);
}
if (rawName.toString().equals("xmlns")) {
if (namespace==null) {
XPathException err = new XPathException("Invalid attribute name: " + rawName, this);
err.setErrorCode((isXSLT() ? "XTDE0855" : "XQDY0044"));
err.setXPathContext(context);
throw dynamicError(this, err, context);
}
}
if (prefix.equals("xmlns")) {
if (namespace==null) {
XPathException err = new XPathException("Invalid attribute name: " + rawName, this);
err.setErrorCode((isXSLT() ? "XTDE0860" : "XQDY0044"));
err.setXPathContext(context);
throw dynamicError(this, err, context);
} else {
// ignore the prefix "xmlns"
prefix = "";
}
}
} else if (nameValue instanceof QNameValue && allowNameAsQName) {
// this is allowed in XQuery
localName = ((QNameValue)nameValue).getLocalName();
uri = ((QNameValue)nameValue).getNamespaceURI();
if (uri == null) {
uri = "";
}
if (localName.equals("xmlns") && uri.length()==0) {
XPathException err = new XPathException("Invalid attribute name: xmlns", this);
err.setErrorCode("XQDY0044");
err.setXPathContext(context);
throw dynamicError(this, err, context);
}
if ("xmlns".equals(prefix) || uri.equals("http://www.w3.org/2000/xmlns/")) {
XPathException err = new XPathException("Invalid attribute namespace: http://www.w3.org/2000/xmlns/", this);
err.setErrorCode("XQDY0044");
err.setXPathContext(context);
throw dynamicError(this, err, context);
}
if (uri.length() == 0) {
prefix = "";
} else {
prefix = ((QNameValue)nameValue).getPrefix();
if (prefix.length()==0) {
if (uri.equals(NamespaceConstant.XML)) {
prefix = "xml";
} else {
prefix = pool.suggestPrefixForURI(uri);
if (prefix == null) {
prefix = "ns0";
}
}
}
// If the prefix is a duplicate, a different one will be substituted
}
} else {
XPathException err = new XPathException("Attribute name must be either a string or a QName", this);
err.setErrorCode("XPTY0004");
err.setIsTypeError(true);
err.setXPathContext(context);
throw dynamicError(this, err, context);
}
if (namespace == null && uri == null) {
if (prefix.length() == 0) {
uri = "";
} else {
uri = nsContext.getURIForPrefix(prefix, false);
if (uri==null) {
XPathException err = new XPathException("Undeclared prefix in attribute name: " + prefix, this);
err.setErrorCode((isXSLT() ? "XTDE0860" : "XQDY0074"));
err.setXPathContext(context);
throw dynamicError(this, err, context);
}
}
} else {
if (uri == null) {
// generate a name using the supplied namespace URI
if (namespace instanceof StringLiteral) {
uri = ((StringLiteral)namespace).getStringValue();
} else {
uri = namespace.evaluateAsString(context).toString();
if (!AnyURIValue.isValidURI(uri)) {
XPathException de = new XPathException("The value of the namespace attribute must be a valid URI");
de.setErrorCode("XTDE0865");
de.setXPathContext(context);
de.setLocator(this);
throw de;
}
}
}
if (uri.length() == 0) {
// there is a special rule for this case in the XSLT specification;
// we force the attribute to go in the null namespace
prefix = "";
} else {
// if a suggested prefix is given, use it; otherwise try to find a prefix
// associated with this URI; if all else fails, invent one.
if (prefix.length() == 0) {
prefix = pool.suggestPrefixForURI(uri);
if (prefix == null) {
prefix = "ns0";
// this will be replaced later if it is already in use
}
}
}
}
return pool.allocate(prefix, uri, localName);
}
/**
* Diagnostic print of expression structure. The abstract expression tree
* is written to the supplied output destination.
*/
public void explain(ExpressionPresenter out) {
out.startElement("computedAttribute");
out.emitAttribute("validation", Validation.toString(validationAction));
if (schemaType != null) {
out.emitAttribute("type", schemaType.getDescription());
}
out.startSubsidiaryElement("name");
attributeName.explain(out);
out.endSubsidiaryElement();
if (namespace != null) {
out.startSubsidiaryElement("namespace");
namespace.explain(out);
out.endSubsidiaryElement();
}
out.startSubsidiaryElement("select");
getSelect().explain(out);
out.endSubsidiaryElement();
out.endElement();
}
}
//
// The contents of this file are subject to the Mozilla Public License Version 1.0 (the "License");
// you may not use this file except in compliance with the License. You may obtain a copy of the
// License at http://www.mozilla.org/MPL/
//
// Software distributed under the License is distributed on an "AS IS" basis,
// WITHOUT WARRANTY OF ANY KIND, either express or implied.
// See the License for the specific language governing rights and limitations under the License.
//
// The Original Code is: all this file.
//
// The Initial Developer of the Original Code is Michael H. Kay.
//
// Portions created by (your name) are Copyright (C) (your legal entity). All Rights Reserved.
//
// Contributor(s): none.
//