NAPI

foundation/arkui/napi
   ├── interfaces
   │   └── kits
   │       └── napi           # NAPI header files
   ├── module_manager         # Module manager
   ├── native_engine          # NativeEngine abstraction layer
   │   └── impl
   │       └── ark            # Ark-based NativeEngine implementation
   ├── scope_manager          # Scope manager
   └── test                   # Test code

function getAppName(): string;

// app.cpp
#include <stdio.h>
#include <string.h>
#include "napi/native_api.h"
#include "napi/native_node_api.h"

struct AsyncCallbackInfo {
    napi_env env;
    napi_async_work asyncWork;
    napi_deferred deferred;
};

// C/C++ function corresponding to getAppName()
napi_value JSGetAppName(napi_env env, napi_callback_info info) {
    napi_deferred deferred;
    napi_value promise;
    // Create a promise.
    NAPI_CALL(env, napi_create_promise(env, &deferred, &promise));

    AsyncCallbackInfo* asyncCallbackInfo = new AsyncCallbackInfo {
        .env = env,
        .asyncWork = nullptr,
        .deferred = deferred,
    };

    napi_value resourceName;
    napi_create_string_latin1(env, "GetAppName", NAPI_AUTO_LENGTH, &resourceName);
    // Create a queue of asynchronous tasks.
    napi_create_async_work(
        env, nullptr, resourceName,
        // Callback for an asynchronous task
        [](napi_env env, void* data) {},
        // Callback after the asynchronous task is complete
        [](napi_env env, napi_status status, void* data) {
            AsyncCallbackInfo* asyncCallbackInfo = (AsyncCallbackInfo*)data;
            napi_value appName;
            const char* str = "com.example.helloworld";
            napi_create_string_utf8(env, str, strlen(str), &appName);
            // Trigger the callback.
            napi_resolve_deferred(asyncCallbackInfo->env, asyncCallbackInfo->deferred, appName);
            napi_delete_async_work(env, asyncCallbackInfo->asyncWork);
            delete asyncCallbackInfo;
        },
        (void*)asyncCallbackInfo, &asyncCallbackInfo->asyncWork);
    napi_queue_async_work(env, asyncCallbackInfo->asyncWork);
    return promise;
}

// Export the module.
static napi_value AppExport(napi_env env, napi_value exports)
{
    static napi_property_descriptor desc[] = {
        DECLARE_NAPI_FUNCTION("getAppName", JSGetAppName),
    };
    NAPI_CALL(env, napi_define_properties(env, exports, sizeof(desc) / sizeof(desc[0]), desc));
    return exports;
}

// App module description
static napi_module appModule = {
    .nm_version = 1,
    .nm_flags = 0,
    .nm_filename = nullptr,
    .nm_register_func = AppExport,
    .nm_modname = "app",
    .nm_priv = ((void*)0),
    .reserved = {0}
};

// Register the module.
extern "C" __attribute__((constructor)) void AppRegister()
{
    napi_module_register(&appModule);
}

// BUILD.gn
import("//build/ohos.gni")
ohos_shared_library("app") {
  # Specify the source file to build.
  sources = [
    "app.cpp",
  ]
  # Specify build dependencies.
  deps = [ "//foundation/arkui/napi:ace_napi" ]
  # Specify the directory where the library is generated.
  relative_install_dir = "module"
  subsystem_name = "arkui"
  part_name = "napi"
}

import app from '@ohos.app'
export default {
  testGetAppName() {
    app.getAppName().then(function (data) {
      console.info('app name: ' + data);
    });
  }
}