com.trolltech.qt.xmlpatterns
Class QXmlResultItems

java.lang.Object
  extended by com.trolltech.qt.internal.QSignalEmitterInternal
      extended by com.trolltech.qt.QSignalEmitter
          extended by com.trolltech.qt.QtJambiObject
              extended by com.trolltech.qt.xmlpatterns.QXmlResultItems
All Implemented Interfaces:
QtJambiInterface

public class QXmlResultItems
extends QtJambiObject

The QXmlResultItems class iterates through the results of evaluating an XQuery in QXmlQuery. QXmlResultItems presents the evaluation of an associated query as a sequence of QXmlItems. The sequence is traversed by repeatedly calling next(), which actually produces the sequence by lazy evaluation of the query.

  QXmlQuery query = new QXmlQuery();
  query.setQuery("<e/>, 1, 'two'");
  QXmlResultItems result = new QXmlResultItems();

  if(query.isValid())
  {
    query.evaluateToResult(result);
    QXmlItem item = result.next();
    while(!item.isNull())
    {
        // Use item
        item = result.next();
    }

    if(result.hasError())
        throw new RuntimeException("Runtime error!");
  }
An effect of letting next() produce the sequence by lazy evaluation is that a query error can occur on any call to next(). If an error occurs, both next() and current() will return the null QXmlItem, and hasError() will return true.

QXmlResultItems can be thought of as an "iterator" that traverses the sequence of query results once, in the forward direction. Each call to next() advances the iterator to the next QXmlItem in the sequence and returns it, and current() always returns the QXmlItem that next() returned the last time it was called.

See also:
QXmlItem::isNode(), QXmlItem::isAtomicValue(), and QXmlNodeModelIndex.


Nested Class Summary
 
Nested classes/interfaces inherited from class com.trolltech.qt.QSignalEmitter
QSignalEmitter.AbstractSignal, QSignalEmitter.PrivateSignal0, QSignalEmitter.PrivateSignal1, QSignalEmitter.PrivateSignal2, QSignalEmitter.PrivateSignal3, QSignalEmitter.PrivateSignal4, QSignalEmitter.PrivateSignal5, QSignalEmitter.PrivateSignal6, QSignalEmitter.PrivateSignal7, QSignalEmitter.PrivateSignal8, QSignalEmitter.PrivateSignal9, QSignalEmitter.Signal0, QSignalEmitter.Signal1, QSignalEmitter.Signal2, QSignalEmitter.Signal3, QSignalEmitter.Signal4, QSignalEmitter.Signal5, QSignalEmitter.Signal6, QSignalEmitter.Signal7, QSignalEmitter.Signal8, QSignalEmitter.Signal9
 
Nested classes/interfaces inherited from class com.trolltech.qt.internal.QSignalEmitterInternal
com.trolltech.qt.internal.QSignalEmitterInternal.AbstractSignalInternal
 
Field Summary
 
Fields inherited from class com.trolltech.qt.internal.QSignalEmitterInternal
currentSender
 
Constructor Summary
QXmlResultItems()
          Constructs an instance of QXmlResultItems.
 
Method Summary
 QXmlItem current()
          Returns the current item.
 boolean hasError()
          If an error occurred during evaluation of the query, true is returned.
 QXmlItem next()
          Returns the next result in the sequence produced by lazy evaluation of the associated query.
 
Methods inherited from class com.trolltech.qt.QtJambiObject
dispose, disposed, equals, finalize, reassignNativeResources, tr, tr, tr
 
Methods inherited from class com.trolltech.qt.QSignalEmitter
blockSignals, disconnect, disconnect, signalsBlocked, signalSender, thread
 
Methods inherited from class com.trolltech.qt.internal.QSignalEmitterInternal
__qt_signalInitialization
 
Methods inherited from class java.lang.Object
clone, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 
Methods inherited from interface com.trolltech.qt.QtJambiInterface
disableGarbageCollection, nativeId, nativePointer, reenableGarbageCollection, setJavaOwnership
 

Constructor Detail

QXmlResultItems

public QXmlResultItems()
Constructs an instance of QXmlResultItems.

Method Detail

current

public final QXmlItem current()
Returns the current item. The current item is the last item that was produced and returned by next().

Returns a null QXmlItem if there is no associated QXmlQuery.


hasError

public final boolean hasError()
If an error occurred during evaluation of the query, true is returned.

Returns false if query evaluation has been done.


next

public final QXmlItem next()
Returns the next result in the sequence produced by lazy evaluation of the associated query. When the returned QXmlItem is null, either the evaluation terminated normally without producing another result, or an error occurred. Call hasError() to determine whether the null item was caused by normal termination or by an error.

Returns a null QXmlItem if there is no associated QXmlQuery.