private Node composeNode(Node parent) {
recursiveNodes.add(parent);
if (parser.checkEvent(Event.ID.Alias)) {
AliasEvent event = (AliasEvent) parser.getEvent();
String anchor = event.getAnchor();
if (!anchors.containsKey(anchor)) {
throw new ComposerException(
null, null, "found undefined alias " + anchor, event.getStartMark());
}
Node result = anchors.get(anchor);
if (recursiveNodes.remove(result)) {
result.setTwoStepsConstruction(true);
}
return result;
}
NodeEvent event = (NodeEvent) parser.peekEvent();
String anchor = null;
anchor = event.getAnchor();
// the check for duplicate anchors has been removed (issue 174)
Node node = null;
if (parser.checkEvent(Event.ID.Scalar)) {
node = composeScalarNode(anchor);
} else if (parser.checkEvent(Event.ID.SequenceStart)) {
node = composeSequenceNode(anchor);
} else {
node = composeMappingNode(anchor);
}
recursiveNodes.remove(parent);
return node;
}
protected void composeMappingChildren(List<NodeTuple> children, MappingNode node) {
Node itemKey = composeKeyNode(node);
if (itemKey.getTag().equals(Tag.MERGE)) {
node.setMerged(true);
}
Node itemValue = composeValueNode(node);
children.add(new NodeTuple(itemKey, itemValue));
}
/**
* Reads a document from a source that contains only one document.
*
* <p>If the stream contains more than one document an exception is thrown.
*
* @return The root node of the document or <code>null</code> if no document is available.
*/
public Node getSingleNode() {
// Drop the STREAM-START event.
parser.getEvent();
// Compose a document if the stream is not empty.
Node document = null;
if (!parser.checkEvent(Event.ID.StreamEnd)) {
document = composeDocument();
}
// Ensure that the stream contains no more documents.
if (!parser.checkEvent(Event.ID.StreamEnd)) {
Event event = parser.getEvent();
throw new ComposerException(
"expected a single document in the stream",
document.getStartMark(),
"but found another document",
event.getStartMark());
}
// Drop the STREAM-END event.
parser.getEvent();
return document;
}
