Napi::FunctionReference is a subclass of Napi::Reference, and is equivalent to an instance of Napi::Reference<Napi::Function>. This means that a Napi::FunctionReference holds a Napi::Function, and a count of the number of references to that Napi::Function. When the count is greater than 0, a Napi::FunctionReference is not eligible for garbage collection. This ensures that the Function will remain accessible, even if the original reference to it is no longer available. Napi::FunctionReference allows the referenced JavaScript function object to be called from a native add-on with two different methods: Call and MakeCallback. See the documentation for Napi::Function for when Call should be used instead of MakeCallback and vice-versa.

The Napi::FunctionReference class inherits its behavior from the Napi::Reference class (for more info see: Napi::Reference).

Creates a "weak" reference to the value, in that the initial reference count is set to 0.

static FunctionReference Weak(const Function& value);

• [in] value: The value which is to be referenced.

Returns the newly created reference.

Creates a "persistent" reference to the value, in that the initial reference count is set to 1.

static FunctionReference Persistent(const Function& value);

• [in] value: The value which is to be referenced.

Returns the newly created reference.

Creates a new empty instance of Napi::FunctionReference.

FunctionReference();

Creates a new instance of the Napi::FunctionReference.

FunctionReference(napi_env env, napi_ref ref);

• [in] env: The environment in which to construct the Napi::FunctionReference object.
• [in] ref: The N-API reference to be held by the Napi::FunctionReference.

Returns a newly created Napi::FunctionReference object.

Constructs a new instance by calling the constructor held by this reference.

Napi::Object New(const std::initializer_list<napi_value>& args) const;

• [in] args: Initializer list of JavaScript values as napi_value representing the arguments of the contructor function.

Returns a new JavaScript object.

Constructs a new instance by calling the constructor held by this reference.

Napi::Object New(const std::vector<napi_value>& args) const;

• [in] args: Vector of JavaScript values as napi_value representing the arguments of the constructor function.

Returns a new JavaScript object.

Calls a referenced Javascript function from a native add-on.

Napi::Value Call(const std::initializer_list<napi_value>& args) const;

• [in] args: Initializer list of JavaScript values as napi_value representing the arguments of the referenced function.

Returns a Napi::Value representing the JavaScript object returned by the referenced function.

Calls a referenced Javascript function from a native add-on.

Napi::Value Call(const std::vector<napi_value>& args) const;

• [in] args: Vector of JavaScript values as napi_value representing the arguments of the referenced function.

Returns a Napi::Value representing the JavaScript object returned by the referenced function.

Calls a referenced Javascript function from a native add-on.

Napi::Value Call(napi_value recv, const std::initializer_list<napi_value>& args) const;

• [in] recv: The this object passed to the referenced function when it's called.
• [in] args: Initializer list of JavaScript values as napi_value representing the arguments of the referenced function.

Returns a Napi::Value representing the JavaScript object returned by the referenced function.

Calls a referenced Javascript function from a native add-on.

Napi::Value Call(napi_value recv, const std::vector<napi_value>& args) const;

• [in] recv: The this object passed to the referenced function when it's called.
• [in] args: Vector of JavaScript values as napi_value representing the arguments of the referenced function.

Returns a Napi::Value representing the JavaScript object returned by the referenced function.

Calls a referenced Javascript function from a native add-on after an asynchronous operation.

Napi::Value MakeCallback(napi_value recv, const std::initializer_list<napi_value>& args) const;

• [in] recv: The this object passed to the referenced function when it's called.
• [in] args: Initializer list of JavaScript values as napi_value representing the arguments of the referenced function.

Returns a Napi::Value representing the JavaScript object returned by the referenced function.

Calls a referenced Javascript function from a native add-on after an asynchronous operation.

Napi::Value MakeCallback(napi_value recv, const std::vector<napi_value>& args) const;

• [in] recv: The this object passed to the referenced function when it's called.
• [in] args: Vector of JavaScript values as napi_value representing the arguments of the referenced function.

Returns a Napi::Value representing the JavaScript object returned by the referenced function.

Napi::Value operator ()(const std::initializer_list<napi_value>& args) const;

• [in] args: Initializer list of reference to JavaScript values as napi_value

Returns a Napi::Value representing the JavaScript value returned by the referenced function.