Nan::Callback

Nan::Callback makes it easier to use v8::Function handles as callbacks. A class that wraps a v8::Function handle, protecting it from garbage collection and making it particularly useful for storage and use across asynchronous execution.

• Nan::Callback

Nan::Callback

```c++ class Callback { public: Callback();

explicit Callback(const v8::Local &fn);

~Callback();

bool operator==(const Callback &other) const;

bool operator!=(const Callback &other) const;

v8::Local operator*() const;

MaybeLocal operator()(AsyncResource* async_resource, v8::Local target, int argc = 0, v8::Local argv[] = 0) const;

MaybeLocal operator()(AsyncResource* async_resource, int argc = 0, v8::Local argv[] = 0) const;

void SetFunction(const v8::Local &fn);

v8::Local GetFunction() const;

bool IsEmpty() const;

void Reset(const v8::Local &fn);

void Reset();

MaybeLocal Call(v8::Local target, int argc, v8::Local argv[], AsyncResource async_resource) const; MaybeLocal Call(int argc, v8::Local argv[], AsyncResource async_resource) const;

// Deprecated versions. Use the versions that accept an async_resource instead // as they run the callback in the correct async context as specified by the // resource. If you want to call a synchronous JS function (i.e. on a // non-empty JS stack), you can use Nan::Call instead. v8::Local operator()(v8::Local target, int argc = 0, v8::Local argv[] = 0) const;

v8::Local operator()(int argc = 0, v8::Local argv[] = 0) const; v8::Local Call(v8::Local target, int argc, v8::Local argv[]) const;

v8::Local Call(int argc, v8::Local argv[]) const; }; ```

Example usage:

c++ v8::Local<v8::Function> function; Nan::Callback callback(function); callback.Call(0, 0);