How to use

outE

method

in

com.tinkerpop.gremlin.java.GremlinPipeline

/**
 * Add an OutEdgesPipe to the end of the Pipeline.
 * Emit the outgoing edges for the incoming vertex.
 *
 * @param labels the edge labels to traverse
 * @return the extended Pipeline
 */
public GremlinPipeline<S, Edge> outE(final String... labels) {
  return this.outE(Integer.MAX_VALUE, labels);
}

@Override
protected Pipe getQueryPipe() {
  GremlinPipeline p;
  if (guid.equals("*")) {
    p = new GremlinPipeline().has(Constants.ENTITY_TEXT_PROPERTY_KEY).
        hasNot(Constants.ENTITY_TYPE_PROPERTY_KEY, "Taxonomy").outE();
  } else {
    p = new GremlinPipeline().has(Constants.GUID_PROPERTY_KEY, guid).outE();
  }
  //todo: this is basically the same pipeline used in TagRelation.asPipe()
  p.add(new FilterFunctionPipe<>(new PipeFunction<Edge, Boolean>() {
    @Override
    public Boolean compute(Edge edge) {
      String type = edge.getVertex(Direction.OUT).getProperty(Constants.ENTITY_TYPE_PROPERTY_KEY);
      VertexWrapper v = new TermVertexWrapper(edge.getVertex(Direction.IN));
      return edge.getLabel().startsWith(type) && v.getPropertyKeys().contains("available_as_tag");
    }
  }));
  return p.inV();
}

@Override
public Pipe asPipe() {
  //todo: encapsulate all of this path logic including path sep escaping and normalizing
  final int sepIdx = getField().indexOf(QueryFactory.PATH_SEP_TOKEN);
  final String edgeToken = getField().substring(0, sepIdx);
  GremlinPipeline pipeline = new GremlinPipeline();
  Relation relation = resourceDefinition.getRelations().get(fieldSegments[0]);
  if (relation != null) {
    pipeline = pipeline.outE();
    pipeline.add(relation.asPipe()).inV();
  } else {
    if (resourceDefinition.getProjections().get(fieldSegments[0]) != null) {
      return super.asPipe();
    } else {
      //todo: default Relation implementation
      pipeline = pipeline.outE().has("label", Text.REGEX, String.format(".*\\.%s", edgeToken)).inV();
    }
  }
  //todo: set resource definition from relation on underlying expression where appropriate
  String childFieldName = getField().substring(sepIdx + QueryFactory.PATH_SEP_TOKEN.length());
  underlyingExpression.setField(childFieldName);
  Pipe childPipe;
  if (childFieldName.contains(QueryFactory.PATH_SEP_TOKEN)) {
    childPipe = new ProjectionQueryExpression(underlyingExpression, resourceDefinition).asPipe();
  } else {
    childPipe = underlyingExpression.asPipe();
  }
  pipeline.add(childPipe);
  return negate ? new FilterFunctionPipe(new ExcludePipeFunction(pipeline)) : pipeline;
}