/**
 * Copyright (c) 2015-present, Facebook, Inc.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */

package com.facebook.react.bridge;

import java.lang.annotation.Retention;

import static java.lang.annotation.RetentionPolicy.RUNTIME;

/**
 * Annotation which is used to mark methods that are exposed to React Native.
 *
 * This applies to derived classes of {@link BaseJavaModule}, which will generate a list
 * of exported methods by searching for those which are annotated with this annotation
 * and adding a JS callback for each.
 */
@Retention(RUNTIME)
public @interface ReactMethod {
  /**
   * Whether the method can be called from JS synchronously **on the JS thread**,
   * possibly returning a result.
   *
   * WARNING: in the vast majority of cases, you should leave this to false which allows
   * your native module methods to be called asynchronously: calling methods
   * synchronously can have strong performance penalties and introduce threading-related
   * bugs to your native modules.
   *
   * In order to support remote debugging, both the method args and return type must be
   * serializable to JSON: this means that we only support the same args as
   * {@link ReactMethod}, and the hook can only be void or return JSON values (e.g. bool,
   * number, String, {@link WritableMap}, or {@link WritableArray}). Calling these
   * methods when running under the websocket executor is currently not supported.
   */
  boolean isBlockingSynchronousMethod() default false;
}
