ConditionTask

A task whose boolean decides which of two tasks runs; the other is skipped.

Register one with DagDef.If, then name the sides with ConditionRef.Then and ConditionRef.Else:

public class HasRows implements ConditionTask {
  @Override
  public boolean decide(Context context, Client client) {
    return ((Number) client.getXCom("extract")).longValue() > 0;
  }
}

The SDK runs decide and pushes its result as this task's return value, so execute is never called.

See also