callbackinfo.md 2.5 KB

CallbackInfo

The object representing the components of the JavaScript request being made.

The Napi::CallbackInfo object is usually created and passed by the Node.js runtime or node-addon-api infrastructure.

The Napi::CallbackInfo object contains the arguments passed by the caller. The number of arguments is returned by the Length method. Each individual argument can be accessed using the operator[] method.

The SetData and Data methods are used to set and retrieve the data pointer contained in the Napi::CallbackInfo object.

Methods

Constructor

Napi::CallbackInfo::CallbackInfo(napi_env env, napi_callback_info info);
  • [in] env: The napi_env environment in which to construct the Napi::CallbackInfo object.
  • [in] info: The napi_callback_info data structure from which to construct the Napi::CallbackInfo object.

Env

Napi::Env Napi::CallbackInfo::Env() const;

Returns the Env object in which the request is being made.

NewTarget

Napi::Value Napi::CallbackInfo::NewTarget() const;

Returns the new.target value of the constructor call. If the function that was invoked (and for which the Napi::NCallbackInfo was passed) is not a constructor call, a call to IsEmpty() on the returned value returns true.

IsConstructCall

bool Napi::CallbackInfo::IsConstructCall() const;

Returns a bool indicating if the function that was invoked (and for which the Napi::CallbackInfo was passed) is a constructor call.

Length

size_t Napi::CallbackInfo::Length() const;

Returns the number of arguments passed in the Napi::CallbackInfo object.

operator []

const Napi::Value operator [](size_t index) const;
  • [in] index: The zero-based index of the requested argument.

Returns a Napi::Value object containing the requested argument.

This

Napi::Value Napi::CallbackInfo::This() const;

Returns the JavaScript this value for the call

Data

void* Napi::CallbackInfo::Data() const;

Returns the data pointer for the callback.

SetData

void Napi::CallbackInfo::SetData(void* data);
  • [in] data: The new data pointer to associate with this Napi::CallbackInfo object.

Returns void.

Not documented here

Napi::CallbackInfo::~CallbackInfo();
// Disallow copying to prevent multiple free of _dynamicArgs
Napi::CallbackInfo::CallbackInfo(CallbackInfo const &) = delete;
void Napi::CallbackInfo::operator=(CallbackInfo const &) = delete;