如何从NanAsyncWorker返回一个新的对象？

我正在做一个node.js / io.js本地插件，我需要从asynchronouscallback中创build一个新的本地对象。

使用南帮助者，我有这样的东西：

class MyObject : public node::ObjectWrap { /* definition */ }; class MyWorker : public NanAsyncWorker { bool varForMyObject; virtual void Execute() {/* do stuff and sets varForMyObject */} virtual void HandleOKCallback() { NanScope(); MyObject* obj = new MyObject(varForMyObject); Local<Value> argv[] = { NanNull(), obj // ??? }; callback->Call(2, argv); } }; 

我不知道如何包装对象，而无需访问参数。

帮帮我？

Answer 1

你应该手动创buildjavascript对象，例如：

 //some_class.h class SomeClass { public: std::string id; int value; SomeClass() {}; SomeClass(std::string id, int value): id(id), value(value) {}; static SomeClass *unpack(v8::Isolate *isolate, const v8::Local<v8::Object> object) { using namespace v8; SomeClass *p = new SomeClass(); Local<Value> _id = object->Get(String::NewFromUtf8(isolate, "id")); String::Utf8Value utf8String(_id); p->id = std::string(*utf8String); p->value = static_cast<int>(object->Get(String::NewFromUtf8(isolate, "value"))->NumberValue()); return p; } static v8::Local<v8::Object> pack(v8::Isolate *isolate, const SomeClass *object) { using namespace v8; Local<Object> obj = Object::New(isolate); obj->Set(String::NewFromUtf8(isolate, "id"), String::NewFromUtf8(isolate, object->id.c_str())); obj->Set(String::NewFromUtf8(isolate, "value"), Integer::New(isolate, object->value)); return obj; }; } 

然后在你的工人：

 class MyObject : public node::ObjectWrap { /* definition */ }; class MyWorker : public NanAsyncWorker { virtual void Execute() {/* do stuff and sets varForMyObject */} virtual void HandleOKCallback() { NanScope(); SomeClass *c = new SomeClass("id", 123); Local<Value> argv[] = { NanNull(), SomeClass::pack(v8::Isolate::GetCurrent(), c) }; callback->Call(2, argv); } };