/**
* Run an updating query, writing back eligible updated node to persistent storage.
*
* <p>A node is eligible to be written back to disk if it is present in the document pool, which
* generally means that it was originally read using the doc() or collection() function.
*
* <p>On completion of this method it is generally unsafe to rely on the contents or relationships
* of NodeInfo objects that were obtained before the updating query was run. Such objects may or
* may not reflect the results of the update operations. This is especially true in the case of
* nodes that are part of a subtree that has been deleted (detached from its parent). Instead, the
* new updated tree should be accessed by navigation from the root nodes returned by this method.
*
* <p>If one or more eligible updated nodes cannot be written back to disk, perhaps because the
* URI identifies a non-updatable location, then an exception is thrown. In this case it is
* undefined
*
* @param dynamicEnv the dynamic context for query execution
* @throws XPathException if evaluation of the update query fails, or it this is not an updating
* query
*/
public void runUpdate(DynamicQueryContext dynamicEnv, UpdateAgent agent) throws XPathException {
if (!isUpdating) {
throw new XPathException("Calling runUpdate() on a non-updating query");
}
Configuration config = executable.getConfiguration();
Controller controller = newController();
initializeController(dynamicEnv, controller);
XPathContextMajor context = initialContext(dynamicEnv, controller);
try {
PendingUpdateList pul = config.newPendingUpdateList();
context.openStackFrame(stackFrameMap);
expression.evaluatePendingUpdates(context, pul);
pul.apply(context, staticContext.getRevalidationMode());
for (Iterator iter = pul.getAffectedTrees().iterator(); iter.hasNext(); ) {
NodeInfo node = (NodeInfo) iter.next();
agent.update(node, controller);
}
} catch (XPathException e) {
if (!e.hasBeenReported()) {
try {
controller.getErrorListener().fatalError(e);
} catch (TransformerException e2) {
// ignore secondary error
}
}
throw e;
}
}
/**
* Get the path map for the query expression
*
* @return the path map (which is constructed if this has not already been done)
*/
public PathMap getPathMap() {
if (pathMap == null) {
pathMap = new PathMap(expression);
}
HashMap map = executable.getCompiledGlobalVariables();
if (map != null) {
Iterator iter = map.values().iterator();
while (iter.hasNext()) {
GlobalVariable var = (GlobalVariable) iter.next();
Expression select = var.getSelectExpression();
select.addToPathMap(pathMap, null);
}
}
return pathMap;
}
/**
* Ask whether this query uses the context item
*
* @return true if the context item is referenced either in the query body or in the initializer
* of any global variable
*/
public boolean usesContextItem() {
if ((expression.getDependencies() & StaticProperty.DEPENDS_ON_FOCUS) != 0) {
return true;
}
HashMap map = executable.getCompiledGlobalVariables();
if (map != null) {
Iterator iter = map.values().iterator();
while (iter.hasNext()) {
GlobalVariable var = (GlobalVariable) iter.next();
Expression select = var.getSelectExpression();
if (select != null && (select.getDependencies() & StaticProperty.DEPENDS_ON_FOCUS) != 0) {
return true;
}
}
}
return false;
}
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
}
}
}
