package client.net.sf.saxon.ce.expr.instruct;
import client.net.sf.saxon.ce.Controller;
import client.net.sf.saxon.ce.LogController;
import client.net.sf.saxon.ce.event.Receiver;
import client.net.sf.saxon.ce.expr.*;
import client.net.sf.saxon.ce.functions.SystemFunction;
import client.net.sf.saxon.ce.lib.NamespaceConstant;
import client.net.sf.saxon.ce.lib.StandardURIChecker;
import client.net.sf.saxon.ce.om.*;
import client.net.sf.saxon.ce.trans.XPathException;
import client.net.sf.saxon.ce.type.BuiltInAtomicType;
import client.net.sf.saxon.ce.type.ItemType;
import client.net.sf.saxon.ce.type.TypeHierarchy;
import client.net.sf.saxon.ce.value.*;
import client.net.sf.saxon.ce.value.StringValue;
import java.util.ArrayList;
import java.util.Iterator;
import com.google.gwt.logging.client.LogConfiguration;
/**
* An instruction representing an xsl:element element in an XSLT stylesheet,
* or a computed element constructor in XQuery. (In both cases, if the element name
* is expressed as a compile-time expression, then a FixedElement instruction
* is used instead.)
* @see FixedElement
*/
public class ComputedElement extends ElementCreator {
private Expression elementName;
private Expression namespace = null;
private NamespaceResolver nsContext;
/**
* Create an instruction that creates a new element node
*
* @param elementName Expression that evaluates to produce the name of the
* element node as a lexical QName
* @param namespace Expression that evaluates to produce the namespace URI of
* the element node. Set to null if the namespace is to be deduced from the prefix
* of the elementName.
* @param nsContext Saved copy of the static namespace context for the instruction.
* Can be set to null if namespace is supplied. This namespace context
* must resolve the null prefix correctly, based on the different rules for
* XSLT and XQuery.
* @param inheritNamespaces true if child elements automatically inherit the namespaces of their parent
*/
public ComputedElement(Expression elementName,
Expression namespace,
NamespaceResolver nsContext,
boolean inheritNamespaces) {
this.elementName = elementName;
this.namespace = namespace;
this.nsContext = nsContext;
this.inheritNamespaces = inheritNamespaces;
adoptChildExpression(elementName);
adoptChildExpression(namespace);
if (LogConfiguration.loggingIsEnabled() && LogController.traceIsEnabled()) {
this.AddTraceProperty("name", elementName);
}
}
/**
* Get the namespace resolver that provides the namespace bindings defined in the static context
* @return the namespace resolver
*/
public NamespaceResolver getNamespaceResolver() {
return nsContext;
}
public Expression simplify(ExpressionVisitor visitor) throws XPathException {
elementName = visitor.simplify(elementName);
namespace = visitor.simplify(namespace);
return super.simplify(visitor);
}
public Expression typeCheck(ExpressionVisitor visitor, ItemType contextItemType) throws XPathException {
elementName = visitor.typeCheck(elementName, contextItemType);
RoleLocator role;
TypeHierarchy th = visitor.getConfiguration().getTypeHierarchy();
if (!th.isSubType(elementName.getItemType(th), BuiltInAtomicType.STRING)) {
elementName = SystemFunction.makeSystemFunction("string", new Expression[]{elementName});
}
if (namespace != null) {
namespace = visitor.typeCheck(namespace, contextItemType);
// TODO: not sure there are any circumstances in which this type check can fail
role = new RoleLocator(RoleLocator.INSTRUCTION, "element/namespace", 0);
namespace = TypeChecker.staticTypeCheck(
namespace, SequenceType.SINGLE_STRING, false, role, visitor);
}
if (Literal.isAtomic(elementName)) {
// Check we have a valid lexical QName, whose prefix is in scope where necessary
try {
AtomicValue val = (AtomicValue)((Literal)elementName).getValue();
if (val instanceof StringValue) {
String[] parts = NameChecker.checkQNameParts(val.getStringValueCS());
if (namespace == null) {
String prefix = parts[0];
String uri = getNamespaceResolver().getURIForPrefix(prefix, true);
if (uri == null) {
XPathException se = new XPathException("Prefix " + prefix + " has not been declared");
se.setErrorCode("XPST0081");
se.setIsStaticError(true);
throw se;
}
namespace = new StringLiteral(uri);
}
}
} catch (XPathException e) {
String code = e.getErrorCodeLocalPart();
if (code == null || code.equals("FORG0001")) {
e.setErrorCode("XTDE0820");
} else if (code.equals("XPST0081")) {
e.setErrorCode("XTDE0830");
}
e.maybeSetLocation(getSourceLocator());
e.setIsStaticError(true);
throw e;
}
}
return super.typeCheck(visitor, contextItemType);
}
public Expression optimize(ExpressionVisitor visitor, ItemType contextItemType) throws XPathException {
elementName = visitor.optimize(elementName, contextItemType);
return super.optimize(visitor, contextItemType);
}
public Iterator<Expression> iterateSubExpressions() {
ArrayList list = new ArrayList(3);
list.add(content);
list.add(elementName);
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 (content == original) {
content = replacement;
found = true;
}
if (elementName == original) {
elementName = 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
* @throws client.net.sf.saxon.ce.trans.XPathException if any error is detected
*/
protected void promoteInst(PromotionOffer offer) throws XPathException {
elementName = doPromotion(elementName, offer);
if (namespace != null) {
namespace = doPromotion(namespace, offer);
}
super.promoteInst(offer);
}
/**
* Callback from the superclass ElementCreator to get the nameCode
* for the element name
*
* @param context The evaluation context (not used)
* @param copiedNode
* @return the name code for the element name
*/
public int getNameCode(XPathContext context, NodeInfo copiedNode)
throws XPathException {
Controller controller = context.getController();
NamePool pool = controller.getNamePool();
String prefix = null;
String localName = null;
String uri = null;
// name needs to be evaluated at run-time
AtomicValue nameValue = (AtomicValue)elementName.evaluateItem(context);
if (nameValue == null) {
dynamicError("Invalid element name (empty sequence)", "XTDE0820", context);
}
//nameValue = nameValue.getPrimitiveValue();
if (nameValue instanceof StringValue) { // which includes UntypedAtomic
// this will always be the case in XSLT
CharSequence rawName = nameValue.getStringValueCS();
rawName = Whitespace.trimWhitespace(rawName); // required in XSLT; possibly wrong in XQuery
try {
String[] parts = NameChecker.getQNameParts(rawName);
prefix = parts[0];
localName = parts[1];
} catch (QNameException err) {
String message = "Invalid element name. " + err.getMessage();
if (rawName.length() == 0) {
message = "Supplied element name is a zero-length string";
}
dynamicError(message, "XTDE0820", context);
}
} else {
dynamicError("Computed element name has incorrect type", "XTDE0820", context);
}
if (namespace == null && uri == null) {
// if (prefix.length() == 0) {
// uri = defaultNamespace;
// } else {
uri = nsContext.getURIForPrefix(prefix, true);
if (uri == null) {
dynamicError("Undeclared prefix in element name: " + prefix, "XTDE0830", context);
}
// }
} else {
if (uri == null) {
if (namespace instanceof StringLiteral) {
uri = ((StringLiteral)namespace).getStringValue();
} else {
uri = namespace.evaluateAsString(context).toString();
if (!StandardURIChecker.getInstance().isValidURI(uri)) {
dynamicError("The value of the namespace attribute must be a valid URI", "XTDE0835", context);
}
}
}
if (uri.length() == 0) {
// there is a special rule for this case in the specification;
// we force the element to go in the null namespace
prefix = "";
}
if (prefix.equals("xmlns")) {
// this isn't a legal prefix so we mustn't use it
prefix = "x-xmlns";
}
}
if (uri.equals(NamespaceConstant.XMLNS)) {
dynamicError("Cannot create element in namespace " + uri, "XTDE0835", context);
}
if (uri.equals(NamespaceConstant.XML) != prefix.equals("xml")) {
String message;
if (prefix.equals("xml")) {
message = "When the prefix is 'xml', the namespace URI must be " + NamespaceConstant.XML;
} else {
message = "When the namespace URI is " + NamespaceConstant.XML + ", the prefix must be 'xml'";
}
dynamicError(message, "XTDE0835", context);
}
// TODO: cache the generated names locally to reduce NamePool contention
return pool.allocate(prefix, uri, localName);
}
public String getNewBaseURI(XPathContext context, NodeInfo copiedNode) {
return getBaseURI();
}
/**
* Callback to output namespace nodes for the new element.
*
* @param context The execution context
* @param out the Receiver where the namespace nodes are to be written
* @param nameCode
* @param copiedNode
* @throws XPathException
*/
protected void outputNamespaceNodes(XPathContext context, Receiver out, int nameCode, NodeInfo copiedNode)
throws XPathException {
// no action
}
/**
* Get the name of this instruction for diagnostic and tracing purposes
*/
public int getInstructionNameCode() {
return StandardNames.XSL_ELEMENT;
}
}
// 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.