react-native/ReactAndroid/src/main/java/com/facebook/react/bridge/NativeModule.java

/**
 * Copyright (c) Facebook, Inc. and its affiliates.
 *
 * 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 com.facebook.proguard.annotations.DoNotStrip;

import javax.annotation.Nonnull;


/**
 * A native module whose API can be provided to JS catalyst instances.  {@link NativeModule}s whose
 * implementation is written in Java should extend {@link BaseJavaModule} or {@link
 * ReactContextBaseJavaModule}.  {@link NativeModule}s whose implementation is written in C++
 * must not provide any Java code (so they can be reused on other platforms), and instead should
 * register themselves using {@link CxxModuleWrapper}.
 */
@DoNotStrip
public interface NativeModule {
  interface NativeMethod {
    void invoke(JSInstance jsInstance, ReadableArray parameters);
    String getType();
  }

  /**
   * @return the name of this module. This will be the name used to {@code require()} this module
   * from javascript.
   */
  @Nonnull String getName();

  /**
   * This is called at the end of {@link CatalystApplicationFragment#createCatalystInstance()}
   * after the CatalystInstance has been created, in order to initialize NativeModules that require
   * the CatalystInstance or JS modules.
   */
  void initialize();

  /**
   * Return true if you intend to override some other native module that was registered e.g. as part
   * of a different package (such as the core one). Trying to override without returning true from
   * this method is considered an error and will throw an exception during initialization. By
   * default all modules return false.
   */
  boolean canOverrideExistingModule();

  /**
   * Called before {CatalystInstance#onHostDestroy}
   */
  void onCatalystInstanceDestroy();
}