/**
* Get an iterator over the results of the expression. This returns results without any conversion
* of the returned items to "native" Java classes. The iterator will deliver a sequence of Item
* objects, each item being either a NodeInfo (representing a node) or an AtomicValue
* (representing an atomic value).
*
* <p>
*
* <p>To get the results of the query in the form of an XML document in which each item is wrapped
* by an element indicating its type, use:
*
* <p>
*
* <p><code>QueryResult.wrap(iterator(env))</code>
*
* <p>
*
* <p>To serialize the results to a file, use the QueryResult.serialize() method.
*
* @param env Provides the dynamic query evaluation context
* @return an iterator over the results of the query. The class SequenceIterator is modeled on the
* standard Java Iterator class, but has extra functionality and can throw exceptions when
* errors occur.
* @throws XPathException if a dynamic error occurs in evaluating the query. Some dynamic errors
* will not be reported by this method, but will only be reported when the individual items of
* the result are accessed using the returned iterator.
*/
public SequenceIterator iterator(DynamicQueryContext env) throws XPathException {
if (isUpdating) {
throw new XPathException("Cannot call iterator() on an updating query");
}
Controller controller = newController();
initializeController(env, controller);
try {
Item contextItem = env.getContextItem();
// Bindery bindery = controller.getBindery();
// bindery.openStackFrame();
controller.defineGlobalParameters();
XPathContextMajor context = controller.newXPathContext();
if (contextItem != null) {
if (!staticContext
.getUserQueryContext()
.getRequiredContextItemType()
.matchesItem(contextItem, false, env.getConfiguration())) {
throw new XPathException(
"The supplied context item does not match the required context item type");
}
UnfailingIterator single = SingletonIterator.makeIterator(contextItem);
single.next();
context.setCurrentIterator(single);
controller.setInitialContextItem(contextItem);
}
// In tracing/debugging mode, evaluate all the global variables first
if (controller.getTraceListener() != null) {
controller.preEvaluateGlobals(context);
}
context.openStackFrame(stackFrameMap);
SequenceIterator iterator = expression.iterate(context);
return new ErrorReportingIterator(iterator, controller.getErrorListener());
} catch (XPathException err) {
TransformerException terr = err;
while (terr.getException() instanceof TransformerException) {
terr = (TransformerException) terr.getException();
}
XPathException de = XPathException.makeXPathException(terr);
controller.reportFatalError(de);
throw de;
}
}
/**
* Run the query in pull mode.
*
* <p>
*
* <p>For maximum effect this method should be used when lazyConstructionMode has been set in the
* Configuration.
*
* <p>
*
* <p><b>Note: this method usually has very similar performance to the {@link
* #run(DynamicQueryContext,javax.xml.transform.Result,java.util.Properties)} method (which does
* the same thing), but sometimes it is significantly slower. Therefore, the run() method is
* preferred.</b>
*
* @param dynamicEnv the dynamic context for query evaluation
* @param destination the destination of the query results
* @param outputProperties the serialization parameters
* @see Configuration#setLazyConstructionMode(boolean)
*/
public void pull(DynamicQueryContext dynamicEnv, Result destination, Properties outputProperties)
throws XPathException {
if (isUpdating) {
throw new XPathException("Cannot call pull() on an updating query");
}
Configuration config = dynamicEnv.getConfiguration();
try {
Controller controller = newController();
// initializeController(dynamicEnv, controller);
EventIterator iter = iterateEvents(controller, dynamicEnv);
// iter = new Decomposer(iter, config);
Properties actualProperties = validateOutputProperties(controller, outputProperties);
SerializerFactory sf = config.getSerializerFactory();
PipelineConfiguration pipe = config.makePipelineConfiguration();
pipe.setSerializing(true);
Receiver receiver = sf.getReceiver(destination, pipe, actualProperties);
receiver = new NamespaceReducer(receiver);
if ("yes".equals(actualProperties.getProperty(SaxonOutputKeys.WRAP))) {
receiver = new SequenceWrapper(receiver);
// receiver = new TracingFilter(receiver);
} else {
receiver = new TreeReceiver(receiver);
}
EventIteratorToReceiver.copy(iter, (SequenceReceiver) receiver);
} catch (XPathException err) {
config.reportFatalError(err);
throw err;
}
}
private XPathContextMajor initialContext(DynamicQueryContext dynamicEnv, Controller controller)
throws XPathException {
Item contextItem = dynamicEnv.getContextItem();
controller.defineGlobalParameters();
XPathContextMajor context = controller.newXPathContext();
if (contextItem != null) {
if (!staticContext
.getUserQueryContext()
.getRequiredContextItemType()
.matchesItem(contextItem, false, dynamicEnv.getConfiguration())) {
throw new XPathException(
"The supplied context item does not match the required context item type");
}
UnfailingIterator single = SingletonIterator.makeIterator(contextItem);
single.next();
context.setCurrentIterator(single);
controller.setInitialContextItem(contextItem);
}
return context;
}
private void initializeController(DynamicQueryContext env, Controller controller) {
HashMap parameters = env.getParameters();
if (parameters != null) {
Iterator iter = parameters.keySet().iterator();
while (iter.hasNext()) {
String paramName = (String) iter.next();
Object paramValue = parameters.get(paramName);
controller.setParameter(paramName, paramValue);
}
}
controller.setURIResolver(env.getURIResolver());
controller.setErrorListener(env.getErrorListener());
controller.addTraceListener(env.getTraceListener());
controller.setTraceFunctionDestination(env.getTraceFunctionDestination());
DateTimeValue currentDateTime = env.getCurrentDateTime();
if (currentDateTime != null) {
try {
controller.setCurrentDateTime(currentDateTime);
} catch (XPathException e) {
throw new AssertionError(e); // the value should already have been checked
}
}
}
