C++ 如何从NanAsyncWorker返回新对象?
我正在开发node.js/io.js本机插件,需要从异步回调创建一个新的本机对象 使用nan帮助程序,我得到了如下结果:C++ 如何从NanAsyncWorker返回新对象?,c++,node.js,v8,node-modules,node.js-addon,C++,Node.js,V8,Node Modules,Node.js Addon,我正在开发node.js/io.js本机插件,需要从异步回调创建一个新的本机对象 使用nan帮助程序,我得到了如下结果: class MyObject : public node::ObjectWrap { /* definition */ }; class MyWorker : public NanAsyncWorker { bool varForMyObject; virtual void Execute() {/* do stuff and sets varForMyObject
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);
}
};
类MyObject:public节点::ObjectWrap
{/*定义*/};
类MyWorker:公共工作者
{
bool-varForMyObject;
虚拟void Execute(){/*执行填充并设置varForMyObject*/}
虚拟void HandleOKCallback(){
NanScope();
MyObject*obj=新的MyObject(varForMyObject);
本地argv[]={
NanNull(),
obj/???
};
回调->调用(2,argv);
}
};
在没有访问args参数的情况下,我无法理解如何包装对象
帮助?您应该手动创建javascript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;
};
}
//some_class.h
上课{
公众:
std::字符串id;
int值;
SomeClass(){};
SomeClass(std::stringid,int-value):id(id),value(value){};
静态SomeClass*解包(v8::隔离*隔离,常量v8::本地对象){
使用名称空间v8;
SomeClass*p=新的SomeClass();
本地_id=object->Get(字符串::NewFromUtf8(隔离,“id”);
字符串::Utf8Value utf8String(_id);
p->id=std::string(*utf8String);
p->value=static_cast(对象->获取(字符串::NewFromUtf8(隔离,“值”)->NumberValue());
返回p;
}
静态v8::本地包(v8::隔离*隔离,常量SomeClass*对象){
使用名称空间v8;
本地对象=对象::新建(隔离);
obj->Set(String::NewFromUtf8(隔离,“id”),String::NewFromUtf8(隔离,对象->id.c_str());
对象->设置(字符串::NewFromUtf8(隔离,“值”),整数::新建(隔离,对象->值));
返回obj;
};
}
然后在你的工人中:
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);
}
};
类MyObject:public节点::ObjectWrap
{/*定义*/};
类MyWorker:公共工作者
{
虚拟void Execute(){/*执行填充并设置varForMyObject*/}
虚拟void HandleOKCallback(){
NanScope();
SomeClass*c=新的SomeClass(“id”,123);
本地argv[]={
NanNull(),
SomeClass::pack(v8::Isolate::GetCurrent(),c)
};
回调->调用(2,argv);
}
};
肯定有更好的方法吗?