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The XSLT and XQuery Processor
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Copyright (c) 2018-2022 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.*;
import net.sf.saxon.expr.parser.ContextItemStaticInfo;
import net.sf.saxon.expr.parser.ExpressionTool;
import net.sf.saxon.expr.parser.ExpressionVisitor;
import net.sf.saxon.expr.parser.RebindingMap;
import net.sf.saxon.lib.ParseOptions;
import net.sf.saxon.lib.Validation;
import net.sf.saxon.om.*;
import net.sf.saxon.pattern.*;
import net.sf.saxon.str.UnicodeString;
import net.sf.saxon.trace.ExpressionPresenter;
import net.sf.saxon.trans.XPathException;
import net.sf.saxon.transpile.CSharpSuppressWarnings;
import net.sf.saxon.type.*;
import net.sf.saxon.value.BooleanValue;
import net.sf.saxon.value.SequenceType;
import java.util.Iterator;
/**
* Handler for xsl:copy elements in stylesheet. This only handles copying of the context item. An xsl:copy
* with a select attribute is handled by wrapping the instruction in an xsl:for-each.
*/
public class Copy extends ElementCreator {
private boolean copyNamespaces;
private ItemType selectItemType = AnyItemType.getInstance();
private ItemType resultItemType;
/**
* Create a shallow copy instruction
*
* param select selects the node (or other item) to be copied. Never null.
* param selectSpecified true if the select attribute of xsl:copy was specified explicitly (in which
* case the context for evaluating the body will change)
* @param copyNamespaces true if namespace nodes are to be copied when copying an element
* @param inheritNamespaces true if child elements are to inherit the namespace nodes of their parent
* @param schemaType the Schema type against which the content is to be validated
* @param validation the schema validation mode
*/
public Copy(boolean copyNamespaces,
boolean inheritNamespaces,
SchemaType schemaType,
int validation) {
this.copyNamespaces = copyNamespaces;
this.bequeathNamespacesToChildren = inheritNamespaces;
setValidationAction(validation, schemaType);
preservingTypes = schemaType == null && validation == Validation.PRESERVE;
}
/**
* Say whether namespace nodes are to be copied (in the case of an element)
* @param copy set to true if namespace nodes are to be copied
*/
public void setCopyNamespaces(boolean copy) {
copyNamespaces = copy;
}
/**
* Ask whether namespace nodes are to be copied (in the case of an element)
*
* @return true if all in-scope namespaces are to be copied
*/
public boolean isCopyNamespaces() {
return copyNamespaces;
}
/**
* Simplify an expression. This performs any static optimization (by rewriting the expression
* as a different expression). The default implementation does nothing.
*
*
*
* @throws net.sf.saxon.trans.XPathException
* if an error is discovered during expression rewriting
*/
/*@NotNull*/
@Override
public Expression simplify() throws XPathException {
preservingTypes |= !getPackageData().isSchemaAware();
return super.simplify();
}
/*@NotNull*/
@Override
public Expression typeCheck(ExpressionVisitor visitor, ContextItemStaticInfo contextInfo) throws XPathException {
typeCheckChildren(visitor, contextInfo);
selectItemType = contextInfo.getItemType();
if (selectItemType == ErrorType.getInstance()) {
XPathException err = new XPathException("No context item supplied for xsl:copy", "XTTE0945");
err.setIsTypeError(true);
err.setLocation(getLocation());
throw err;
}
if (selectItemType instanceof NodeTest) {
switch (selectItemType.getPrimitiveType()) {
// For elements and attributes, assume the type annotation will change
case Type.ELEMENT:
this.resultItemType = NodeKindTest.ELEMENT;
break;
case Type.DOCUMENT:
this.resultItemType = NodeKindTest.DOCUMENT;
break;
case Type.ATTRIBUTE:
case Type.TEXT:
case Type.COMMENT:
case Type.PROCESSING_INSTRUCTION:
case Type.NAMESPACE:
ContextItemExpression dot = new ContextItemExpression();
ExpressionTool.copyLocationInfo(this, dot);
CopyOf c = new CopyOf(dot, copyNamespaces, getValidationAction(), getSchemaType(), false);
ExpressionTool.copyLocationInfo(this, c);
return c.typeCheck(visitor, contextInfo);
default:
this.resultItemType = selectItemType;
break;
}
} else {
this.resultItemType = selectItemType;
}
checkContentSequence(visitor.getStaticContext());
return this;
}
/**
* Copy this expression (don't be confused by the method name). This makes a deep copy.
*
* @return the copy of the original expression
* @param rebindings variables that need to be re-bound
*/
/*@NotNull*/
@Override
public Expression copy(RebindingMap rebindings) {
Copy copy = new Copy(
copyNamespaces, bequeathNamespacesToChildren, getSchemaType(), getValidationAction());
ExpressionTool.copyLocationInfo(this, copy);
copy.setContentExpression(getContentExpression().copy(rebindings));
copy.resultItemType = resultItemType;
return copy;
}
/**
* Set the item type of the input
*
* @param type the item type
*/
public void setSelectItemType(ItemType type) {
selectItemType = type;
}
/**
* Determine which aspects of the context the expression depends on. The result is
* a bitwise-or'ed value composed from constants such as XPathContext.VARIABLES and
* XPathContext.CURRENT_NODE. The default implementation combines the intrinsic
* dependencies of this expression with the dependencies of the subexpressions,
* computed recursively. This is overridden for expressions such as FilterExpression
* where a subexpression's dependencies are not necessarily inherited by the parent
* expression.
*
* @return a set of bit-significant flags identifying the dependencies of
* the expression
*/
@Override
public int getIntrinsicDependencies() {
return StaticProperty.DEPENDS_ON_CONTEXT_ITEM;
}
/**
* Get the name of this instruction for diagnostic and tracing purposes
*/
@Override
public int getInstructionNameCode() {
return StandardNames.XSL_COPY;
}
/**
* Get the immediate sub-expressions of this expression, with information about the relationship
* of each expression to its parent expression. Default implementation
* returns a zero-length array, appropriate for an expression that has no
* sub-expressions.
*
* @return an iterator containing the sub-expressions of this expression
*/
@Override
public Iterable operands() {
return contentOp;
}
/**
* Get the item type of the result of this instruction.
*
* @return The context item type.
*/
/*@NotNull*/
@Override
public ItemType getItemType() {
if (resultItemType != null) {
return resultItemType;
} else {
TypeHierarchy th = getConfiguration().getTypeHierarchy();
resultItemType = computeItemType(th);
return resultItemType;
}
}
private ItemType computeItemType(TypeHierarchy th) {
ItemType selectItemType = this.selectItemType; //select.getItemType();
if (!getPackageData().isSchemaAware()) {
return selectItemType;
}
if (selectItemType.getUType().overlaps(UType.ANY_ATOMIC.union(UType.FUNCTION))) {
return selectItemType;
}
// The rest of the code handles the complications of schema-awareness
Configuration config = th.getConfiguration();
if (getSchemaType() != null) {
Affinity e = th.relationship(selectItemType, NodeKindTest.ELEMENT);
if (e == Affinity.SAME_TYPE || e == Affinity.SUBSUMED_BY) {
return new ContentTypeTest(Type.ELEMENT, getSchemaType(), config, false);
}
Affinity a = th.relationship(selectItemType, NodeKindTest.ATTRIBUTE);
if (a == Affinity.SAME_TYPE || a == Affinity.SUBSUMED_BY) {
return new ContentTypeTest(Type.ATTRIBUTE, getSchemaType(), config, false);
}
return AnyNodeTest.getInstance();
} else {
switch (getValidationAction()) {
case Validation.PRESERVE:
return selectItemType;
case Validation.STRIP: {
Affinity e = th.relationship(selectItemType, NodeKindTest.ELEMENT);
if (e == Affinity.SAME_TYPE || e == Affinity.SUBSUMED_BY) {
return new ContentTypeTest(Type.ELEMENT, Untyped.getInstance(), config, false);
}
Affinity a = th.relationship(selectItemType, NodeKindTest.ATTRIBUTE);
if (a == Affinity.SAME_TYPE || a == Affinity.SUBSUMED_BY) {
return new ContentTypeTest(Type.ATTRIBUTE, BuiltInAtomicType.UNTYPED_ATOMIC, config, false);
}
if (e != Affinity.DISJOINT || a != Affinity.DISJOINT) {
// it might be an element or attribute
return AnyNodeTest.getInstance();
} else {
// it can't be an element or attribute, so stripping type annotations can't affect it
return selectItemType;
}
}
case Validation.STRICT:
case Validation.LAX:
if (selectItemType instanceof NodeTest) {
int fp = ((NodeTest) selectItemType).getFingerprint();
if (fp != -1) {
Affinity e = th.relationship(selectItemType, NodeKindTest.ELEMENT);
if (e == Affinity.SAME_TYPE || e == Affinity.SUBSUMED_BY) {
SchemaDeclaration elem = config.getElementDeclaration(fp);
if (elem != null) {
try {
return new ContentTypeTest(Type.ELEMENT, elem.getType(), config, false);
} catch (MissingComponentException e1) {
return new ContentTypeTest(Type.ELEMENT, AnyType.getInstance(), config, false);
}
} else {
// No element declaration now, but there might be one at run-time
return new ContentTypeTest(Type.ELEMENT, AnyType.getInstance(), config, false);
}
}
Affinity a = th.relationship(selectItemType, NodeKindTest.ATTRIBUTE);
if (a == Affinity.SAME_TYPE || a == Affinity.SUBSUMED_BY) {
SchemaDeclaration attr = config.getElementDeclaration(fp);
if (attr != null) {
try {
return new ContentTypeTest(Type.ATTRIBUTE, attr.getType(), config, false);
} catch (MissingComponentException e1) {
return new ContentTypeTest(Type.ATTRIBUTE, AnySimpleType.getInstance(), config, false);
}
} else {
// No attribute declaration now, but there might be one at run-time
return new ContentTypeTest(Type.ATTRIBUTE, AnySimpleType.getInstance(), config, false);
}
}
} else {
Affinity e = th.relationship(selectItemType, NodeKindTest.ELEMENT);
if (e == Affinity.SAME_TYPE || e == Affinity.SUBSUMED_BY) {
return NodeKindTest.ELEMENT;
}
Affinity a = th.relationship(selectItemType, NodeKindTest.ATTRIBUTE);
if (a == Affinity.SAME_TYPE || a == Affinity.SUBSUMED_BY) {
return NodeKindTest.ATTRIBUTE;
}
}
return AnyNodeTest.getInstance();
} else if (selectItemType instanceof AtomicType) {
return selectItemType;
} else {
return AnyItemType.getInstance();
}
default:
throw new IllegalStateException();
}
}
}
/*@NotNull*/
@Override
public Expression optimize(ExpressionVisitor visitor, ContextItemStaticInfo contextItemType) throws XPathException {
Expression exp = super.optimize(visitor, contextItemType);
if (exp == this) {
if (resultItemType == null) {
resultItemType = computeItemType(visitor.getConfiguration().getTypeHierarchy());
}
if (visitor.isOptimizeForStreaming()) {
UType type = contextItemType.getItemType().getUType();
if (!type.intersection(MultipleNodeKindTest.LEAF.getUType()).equals(UType.VOID)) {
// Bug 4346: only do this optimization once
Expression p = getParentExpression();
if (p instanceof Choose && ((Choose)p).size() == 2 && ((Choose)p).getAction(1) == this &&
((Choose) p).getAction(0) instanceof CopyOf) {
return exp;
}
Expression copyOf = new CopyOf(
new ContextItemExpression(), false, getValidationAction(), getSchemaType(), false);
NodeTest leafTest = new MultipleNodeKindTest(type.intersection(MultipleNodeKindTest.LEAF.getUType()));
Expression[] conditions = new Expression[]{
new InstanceOfExpression(
new ContextItemExpression(),
SequenceType.makeSequenceType(leafTest, StaticProperty.EXACTLY_ONE)),
Literal.makeLiteral(BooleanValue.TRUE, this)};
Expression[] actions = new Expression[]{copyOf, this};
Choose choose = new Choose(conditions, actions);
ExpressionTool.copyLocationInfo(this, choose);
return choose;
}
}
}
return exp;
}
/**
* Callback from ElementCreator when constructing an element
*
* @param context XPath dynamic evaluation context
* @param copiedNode the node being copied
* @return the name of the element to be constructed
*/
@Override
public NodeName getElementName(XPathContext context, NodeInfo copiedNode) {
return NameOfNode.makeName(copiedNode);
}
/**
* Get the base URI of a copied element node (the base URI is retained in the new copy)
*
* @param context XPath dynamic evaluation context
* @param copiedNode the node being copied (for xsl:copy), otherwise null
* @return the base URI
*/
@Override
public String getNewBaseURI(XPathContext context, NodeInfo copiedNode) {
return copiedNode.getBaseURI();
}
/**
* Callback to output namespace nodes for the new element.
*
* @param receiver the Receiver where the namespace nodes are to be written
* @param nodeName the element name
* @param copiedNode the node being copied (for xsl:copy), otherwise null
* @throws XPathException if any error occurs
*/
@Override
public void outputNamespaceNodes(Outputter receiver, NodeName nodeName, NodeInfo copiedNode)
throws XPathException {
if (copyNamespaces) {
receiver.namespaces(copiedNode.getAllNamespaces(), ReceiverOption.NAMESPACE_OK);
} else {
// Always output the namespace of the element name itself
NamespaceBinding ns = nodeName.getNamespaceBinding();
if (!ns.isDefaultUndeclaration()) {
receiver.namespace(ns.getPrefix(), ns.getURI(), ReceiverOption.NONE);
}
}
}
@Override
public TailCall processLeavingTail(Outputter out, XPathContext context) throws XPathException {
Controller controller = context.getController();
Item item = context.getContextItem();
if (item == null) {
XPathException err = new XPathException("There is no context item for xsl:copy", "XTTE0945");
err.setIsTypeError(true);
err.setLocation(getLocation());
err.setXPathContext(context);
throw err;
}
if (!(item instanceof NodeInfo)) {
out.append(item, getLocation(), ReceiverOption.ALL_NAMESPACES);
return null;
}
NodeInfo source = (NodeInfo) item;
switch (source.getNodeKind()) {
case Type.ELEMENT:
// use the generic code for creating new elements
return super.processLeavingTail(out, context, (NodeInfo) item);
case Type.ATTRIBUTE:
if (getSchemaType() instanceof ComplexType) {
dynamicError("Cannot copy an attribute when the type requested for validation is a complex type", "XTTE1535", context);
}
try {
CopyOf.copyAttribute(source, (SimpleType) getSchemaType(), getValidationAction(), this, out, context, false);
} catch (NoOpenStartTagException err) {
err.setXPathContext(context);
throw dynamicError(getLocation(), err, context);
}
break;
case Type.TEXT:
UnicodeString tval = source.getUnicodeStringValue();
out.characters(tval, getLocation(), ReceiverOption.NONE);
break;
case Type.PROCESSING_INSTRUCTION:
UnicodeString pval = source.getUnicodeStringValue();
out.processingInstruction(source.getDisplayName(), pval, getLocation(), ReceiverOption.NONE);
break;
case Type.COMMENT:
UnicodeString cval = source.getUnicodeStringValue();
out.comment(cval, getLocation(), ReceiverOption.NONE);
break;
case Type.NAMESPACE:
out.namespace(
((NodeInfo) item).getLocalPart(), item.getStringValue(), ReceiverOption.NONE);
break;
case Type.DOCUMENT:
if (!preservingTypes) {
ParseOptions options = new ParseOptions(getValidationOptions());
options.setSpaceStrippingRule(NoElementsSpaceStrippingRule.getInstance());
controller.getConfiguration().prepareValidationReporting(context, options);
Receiver val = controller.getConfiguration().
getDocumentValidator(out, source.getBaseURI(), options, getLocation());
out = new ComplexContentOutputter(val);
}
if (out.getSystemId() == null) {
out.setSystemId(source.getBaseURI());
}
out.startDocument(ReceiverOption.NONE);
copyUnparsedEntities(source, out);
getContentExpression().process(out, context);
out.endDocument();
break;
default:
throw new IllegalArgumentException("Unknown node kind " + source.getNodeKind());
}
return null;
}
@CSharpSuppressWarnings("UnsafeIteratorConversion")
public static void copyUnparsedEntities(NodeInfo source, Outputter out) throws XPathException {
Iterator unparsedEntities = source.getTreeInfo().getUnparsedEntityNames();
while (unparsedEntities.hasNext()) {
String n = unparsedEntities.next();
String[] details = source.getTreeInfo().getUnparsedEntity(n);
out.setUnparsedEntity(n, details[0], details[1]);
}
}
/**
* Evaluate as an item
*/
@Override
public Item evaluateItem(XPathContext context) throws XPathException {
Controller controller = context.getController();
SequenceCollector seq = controller.allocateSequenceOutputter(1);
seq.getPipelineConfiguration().setHostLanguage(getPackageData().getHostLanguage());
process(new ComplexContentOutputter(seq), context);
seq.close();
Item item = seq.getFirstItem();
seq.reset();
return item;
}
/**
* Get the (partial) name of a class that supports streaming of this kind of expression
*
* @return the partial name of a class that can be instantiated to provide streaming support in Saxon-EE,
* or null if there is no such class
*/
@Override
public String getStreamerName() {
return "Copy";
}
/**
* Diagnostic print of expression structure. The abstract expression tree
* is written to the supplied output destination.
*/
@Override
public void export(ExpressionPresenter out) throws XPathException {
out.startElement("copy", this);
exportValidationAndType(out);
String flags = "";
if (copyNamespaces) {
flags = "c";
}
if (bequeathNamespacesToChildren) {
flags += "i";
}
if (inheritNamespacesFromParent) {
flags += "n";
}
if (isLocal()) {
flags += "l";
}
out.emitAttribute("flags", flags);
String sType = SequenceType.makeSequenceType(selectItemType, getCardinality()).toAlphaCode();
if (sType != null) {
out.emitAttribute("sit", sType);
}
out.setChildRole("content");
getContentExpression().export(out);
out.endElement();
}
}