UnknownBot/node_modules/node-addon-api/doc/env.md

Env

The opaque data structure containing the environment in which the request is being run.

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

Methods

Constructor

Napi::Env::Env(napi_env env);

• [in] env: The napi_env environment from which to construct the Napi::Env object.

napi_env

operator napi_env() const;

Returns the napi_env opaque data structure representing the environment.

Global

Napi::Object Napi::Env::Global() const;

Returns the Napi::Object representing the environment's JavaScript Global Object.

Undefined

Napi::Value Napi::Env::Undefined() const;

Returns the Napi::Value representing the environment's JavaScript Undefined Object.

Null

Napi::Value Napi::Env::Null() const;

Returns the Napi::Value representing the environment's JavaScript Null Object.

IsExceptionPending

bool Napi::Env::IsExceptionPending() const;

Returns a bool indicating if an exception is pending in the environment.

GetAndClearPendingException

Napi::Error Napi::Env::GetAndClearPendingException();

Returns an Napi::Error object representing the environment's pending exception, if any.

RunScript

Napi::Value Napi::Env::RunScript(____ script);

• [in] script: A string containing JavaScript code to execute.

Runs JavaScript code contained in a string and returns its result.

The script can be any of the following types:

• Napi::String
• const char *
• const std::string &

GetInstanceData

template <typename T> T* GetInstanceData();

Returns the instance data that was previously associated with the environment, or nullptr if none was associated.

SetInstanceData

template <typename T> using Finalizer = void (*)(Env, T*);
template <typename T, Finalizer<T> fini = Env::DefaultFini<T>>
void SetInstanceData(T* data);

• [template] fini: A function to call when the instance data is to be deleted. Accepts a function of the form void CleanupData(Napi::Env env, T* data). If not given, the default finalizer will be used, which simply uses the delete operator to destroy T* when the addon instance is unloaded.
• [in] data: A pointer to data that will be associated with the instance of the addon for the duration of its lifecycle.

Associates a data item stored at T* data with the current instance of the addon. The item will be passed to the function fini which gets called when an instance of the addon is unloaded.

SetInstanceData

template <typename DataType, typename HintType>
using FinalizerWithHint = void (*)(Env, DataType*, HintType*);
template <typename DataType,
          typename HintType,
          FinalizerWithHint<DataType, HintType> fini =
            Env::DefaultFiniWithHint<DataType, HintType>>
void SetInstanceData(DataType* data, HintType* hint);

• [template] fini: A function to call when the instance data is to be deleted. Accepts a function of the form void CleanupData(Napi::Env env, DataType* data, HintType* hint). If not given, the default finalizer will be used, which simply uses the delete operator to destroy T* when the addon instance is unloaded.
• [in] data: A pointer to data that will be associated with the instance of the addon for the duration of its lifecycle.
• [in] hint: A pointer to data that will be associated with the instance of the addon for the duration of its lifecycle and will be passed as a hint to fini when the addon instance is unloaded.

Associates a data item stored at T* data with the current instance of the addon. The item will be passed to the function fini which gets called when an instance of the addon is unloaded. This overload accepts an additional hint to be passed to fini.