/**
* 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;
}
}
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;
}
