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An OSGi bundle for Saxon-HE
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// 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.sxpath;
import net.sf.saxon.expr.XPathContext;
import net.sf.saxon.expr.XPathContextMajor;
import net.sf.saxon.expr.instruct.SlotManager;
import net.sf.saxon.expr.parser.TypeChecker;
import net.sf.saxon.lib.CollectionURIResolver;
import net.sf.saxon.lib.UnparsedTextURIResolver;
import net.sf.saxon.om.*;
import net.sf.saxon.trans.SaxonErrorCode;
import net.sf.saxon.trans.XPathException;
import net.sf.saxon.tree.iter.SingletonIterator;
import net.sf.saxon.tree.iter.UnfailingIterator;
import net.sf.saxon.type.ItemType;
import net.sf.saxon.value.SequenceType;
import javax.xml.transform.ErrorListener;
import javax.xml.transform.Source;
import javax.xml.transform.URIResolver;
/**
* This object represents the dynamic XPath execution context for use in the free-standing Saxon XPath API.
* The dynamic context holds the context item and the values of external variables used by the XPath expression.
*
* This object is always created via the method
* {@link net.sf.saxon.sxpath.XPathExpression#createDynamicContext(net.sf.saxon.om.Item)}
*/
public class XPathDynamicContext {
private ItemType contextItemType;
private XPathContextMajor contextObject;
private SlotManager stackFrameMap;
protected XPathDynamicContext(ItemType contextItemType, XPathContextMajor contextObject, SlotManager stackFrameMap) {
this.contextItemType = contextItemType;
this.contextObject = contextObject;
this.stackFrameMap = stackFrameMap;
}
/**
* Set the context item to a node derived from a supplied Source object. This may be
* any implementation of the Source interface recognized by Saxon. Note that the
* Saxon {@link NodeInfo} interface, representing a node in a tree, is one such
* implementation; others include {@link javax.xml.transform.stream.StreamSource},
* {@link javax.xml.transform.sax.SAXSource}, and {@link javax.xml.transform.dom.DOMSource}
*
* @param source The source object representing the node that will be used as the context item
* @throws XPathException if a failure occurs reading or parsing a Source object to build an input tree,
* or if the source is a document that was built under the wrong configuration
*/
public void setContextNode(Source source) throws XPathException {
NodeInfo origin;
if (source instanceof NodeInfo) {
origin = (NodeInfo)source;
if (!origin.getConfiguration().isCompatible(contextObject.getConfiguration())) {
throw new XPathException(
"Supplied node must be built using the same or a compatible Configuration",
SaxonErrorCode.SXXP0004);
}
} else {
origin = contextObject.getConfiguration().buildDocument(source);
}
setContextItem(origin);
}
/**
* Set the context item for evaluation of the XPath Expression
* @param item the context item
* @throws XPathException if the node is in a document that was built under the wrong configuration
*/
public void setContextItem(Item item) throws XPathException {
if (item instanceof NodeInfo) {
if (!((NodeInfo)item).getConfiguration().isCompatible(contextObject.getConfiguration())) {
throw new XPathException(
"Supplied node must be built using the same or a compatible Configuration",
SaxonErrorCode.SXXP0004);
}
}
if (!contextItemType.matchesItem(item, false, contextObject.getConfiguration())) {
throw new XPathException("Supplied context item does not match required context item type " +
contextItemType.toString());
}
UnfailingIterator iter = SingletonIterator.makeIterator(item);
iter.next();
contextObject.setCurrentIterator(iter);
}
/**
* Get the context item
* @return the context item if there is one, or null otherwise
*/
public Item getContextItem() {
return contextObject.getContextItem();
}
/**
* Set the value of an external variable used within the XPath expression
* @param variable the object representing the variable, as returned by the
* {@link net.sf.saxon.sxpath.XPathEvaluator#declareVariable(String, String)} method.
* Note that setting the value of a variable does not modify the {@link XPathVariable}
* object itself, which means that this method is thread-safe.
* @param value The value of the variable.
* @throws XPathException if the supplied value does not conform to the required type of the
* variable; or if the supplied value contains a node that does not belong to this Configuration
* (or another Configuration that shares the same namePool)
*/
public void setVariable(XPathVariable variable, Sequence value) throws XPathException {
SequenceType requiredType = variable.getRequiredType();
if (requiredType != SequenceType.ANY_SEQUENCE) {
XPathException err = TypeChecker.testConformance(value, requiredType, contextObject);
if (err != null) {
throw err;
}
}
SequenceIterator iter = value.iterate();
while (true) {
Item item = iter.next();
if (item == null) {
break;
}
if (item instanceof NodeInfo) {
if (!((NodeInfo)item).getConfiguration().isCompatible(contextObject.getConfiguration())) {
throw new XPathException(
"Supplied node must be built using the same or a compatible Configuration",
SaxonErrorCode.SXXP0004);
}
}
}
int slot = variable.getLocalSlotNumber();
StructuredQName expectedName = (slot >= stackFrameMap.getNumberOfVariables() ? null :
stackFrameMap.getVariableMap().get(slot));
if (!variable.getVariableQName().equals(expectedName)) {
throw new XPathException(
"Supplied XPathVariable is bound to the wrong slot: perhaps it was created using a different static context");
}
contextObject.setLocalVariable(slot, value);
}
/**
* Set an object that will be used to resolve URIs used in
* document(), etc.
*
* @param resolver An object that implements the URIResolver interface, or
* null.
* @since 9.2
*/
public void setURIResolver(URIResolver resolver) {
contextObject.getController().setURIResolver(resolver);
}
/**
* Get the URI resolver.
*
* @return the user-supplied URI resolver if there is one, or null otherwise.
* @since 9.2
*/
public URIResolver getURIResolver() {
return contextObject.getController().getURIResolver();
}
/**
* Set the CollectionURIResolver used for resolving collection URIs.
* Defaults to the CollectionURIResolver registered with the Configuration
* @param resolver the resolver for references to collections
* @since 9.4
*/
public void setCollectionURIResolver(CollectionURIResolver resolver) {
contextObject.getController().setCollectionURIResolver(resolver);
}
/**
* Get the CollectionURIResolver used for resolving references to collections.
* If none has been set on the Controller, returns the
* CollectionURIResolver registered with the Configuration
* @return the resolver for references to collections
* @since 9.4
*/
public CollectionURIResolver getCollectionURIResolver() {
return contextObject.getController().getCollectionURIResolver();
}
/**
* Set the error listener.
*
* @param listener the ErrorListener to be used
* @since 9.2
*/
public void setErrorListener(ErrorListener listener) {
contextObject.getController().setErrorListener(listener);
}
/**
* Get the error listener.
*
* @return the ErrorListener in use
* @since 9.2
*/
public ErrorListener getErrorListener() {
return contextObject.getController().getErrorListener();
}
/**
* For system use: get the wrapped XPathContext object
* @return the underlying XPathContext object
*/
public XPathContext getXPathContextObject() {
return contextObject;
}
/**
* Set an object that will be used to resolve URIs used in
* fn:unparsed-text() and related functions.
*
* @param resolver An object that implements the UnparsedTextURIResolver interface, or
* null.
* @since 9.5
*/
public void setUnparsedTextURIResolver(UnparsedTextURIResolver resolver) {
contextObject.getController().setUnparsedTextURIResolver(resolver);
}
/**
* Get the URI resolver for unparsed text.
*
* @return the user-supplied unparsed text URI resolver if there is one, or the
* system-defined one otherwise
* @since 9.5
*/
public UnparsedTextURIResolver getUnparsedTextURIResolver() {
return contextObject.getController().getUnparsedTextURIResolver();
}
/**
* Check that all external variables have been given a value
* @param stackFrameMap describes the stack frame
* @param numberOfExternals the number of variables that need to be supplied
* @throws XPathException if required variables have not been given a value
*/
protected void checkExternalVariables(/*@NotNull*/ SlotManager stackFrameMap, int numberOfExternals) throws XPathException {
Sequence[] stack = contextObject.getStackFrame().getStackFrameValues();
for (int i=0; i