package wecui.config;
import org.yaml.snakeyaml.introspector.Property;
import org.yaml.snakeyaml.nodes.CollectionNode;
import org.yaml.snakeyaml.nodes.MappingNode;
import org.yaml.snakeyaml.nodes.Node;
import org.yaml.snakeyaml.nodes.NodeTuple;
import org.yaml.snakeyaml.nodes.SequenceNode;
import org.yaml.snakeyaml.nodes.Tag;
import org.yaml.snakeyaml.representer.Represent;
import org.yaml.snakeyaml.representer.Representer;
public class EmptyNullRepresenter extends Representer {
public EmptyNullRepresenter() {
super();
this.nullRepresenter = new EmptyRepresentNull();
}
protected class EmptyRepresentNull implements Represent {
public Node representData(Object data) {
return representScalar(Tag.NULL, ""); // Changed "null" to "" so as to avoid writing nulls
}
}
// Code borrowed from snakeyaml (http://code.google.com/p/snakeyaml/source/browse/src/test/java/org/yaml/snakeyaml/issues/issue60/SkipBeanTest.java)
@Override
protected NodeTuple representJavaBeanProperty(Object javaBean, Property property, Object propertyValue, Tag customTag) {
NodeTuple tuple = super.representJavaBeanProperty(javaBean, property, propertyValue, customTag);
Node valueNode = tuple.getValueNode();
if (valueNode instanceof CollectionNode) {
// Removed null check
if (Tag.SEQ.equals(valueNode.getTag())) {
SequenceNode seq = (SequenceNode) valueNode;
if (seq.getValue().isEmpty()) {
return null; // skip empty lists
}
}
if (Tag.MAP.equals(valueNode.getTag())) {
MappingNode seq = (MappingNode) valueNode;
if (seq.getValue().isEmpty()) {
return null; // skip empty maps
}
}
}
return tuple;
}
// End of borrowed code
}