ElasticsearchPlugin

ElasticsearchPlugin.java

class YelpSearchNativeScriptFactory implements NativeScriptFactory {
  public ExecutableScript newScript(@Nullable Map<String, Object> params) {
    Scorer scorer  = moduleLoader.createScorer(params));
    return new ExecutableScriptImpl(scorer); //1. Create elasticsearch executable script
  }
}

ExecutableScriptImpl.java

class ExecutableScriptImpl extends AbstractDoubleSearchScript implements Document { 
  public ExecutableScriptImpl(final Scorer scorer) {
    this.scorer = scorer;
  }
  public double runAsDouble() {
    return scorer.score(this);  //1. score this document
}