Struct nodex_api::value::JsClass

pub struct JsClass(_);

Implementations

impl JsClass

pub fn new<F, P, T, R, const N: usize>(
    env: NapiEnv,
    name: impl AsRef<str>,
    func: F,
    properties: P
) -> NapiResult<JsClass> where
    T: NapiValueT,
    R: NapiValueT,
    F: FnMut(JsObject, [T; N]) -> NapiResult<R>,
    P: AsRef<[NapiPropertyDescriptor]>, 

Defines a JavaScript class, including:

• A JavaScript constructor function that has the class name. When wrapping a corresponding C++ class, the callback passed via constructor can be used to instantiate a new C++ class instance, which can then be placed inside the JavaScript object instance being constructed using napi_wrap.
• Properties on the constructor function whose implementation can call corresponding static data properties, accessors, and methods of the C++ class (defined by property descriptors with the napi_static attribute).
• Properties on the constructor function’s prototype object. When wrapping a C++ class, non-static data properties, accessors, and methods of the C++ class can be called from the static functions given in the property descriptors without the napi_static attribute after retrieving the C++ class instance placed inside the JavaScript object instance by using napi_unwrap.

When wrapping a C++ class, the C++ constructor callback passed via constructor should be a static method on the class that calls the actual class constructor, then wraps the new C++ instance in a JavaScript object, and returns the wrapper object. See napi_wrap for details.

The JavaScript constructor function returned from napi_define_class is often saved and used later to construct new instances of the class from native code, and/or to check whether provided values are instances of the class. In that case, to prevent the function value from being garbage-collected, a strong persistent reference to it can be created using napi_create_reference, ensuring that the reference count is kept >= 1.

Any non-NULL data which is passed to this API via the data parameter or via the data field of the napi_property_descriptor array items can be associated with the resulting JavaScript constructor (which is returned in the result parameter) and freed whenever the class is garbage-collected by passing both the JavaScript function and the data to napi_add_finalizer.

pub fn new_instance<T>(&self, args: &[T]) -> NapiResult<JsObject> where
    T: NapiValueT, 

This method is used to instantiate a new JavaScript value using a given napi_value that represents the constructor for the object.

Trait Implementations

impl Clone for JsClass

fn clone(&self) -> JsClass

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for JsClass

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl NapiValueT for JsClass

fn from_raw(env: NapiEnv, raw: napi_value) -> JsClass

construct value from raw pointer

fn value(&self) -> JsValue

inner value

fn cast<T: NapiValueT>(&self) -> T

napi_value type cast

fn coerce_to_bool(&self) -> NapiResult<JsBoolean>

This API implements the abstract operation ToBoolean() as defined in Section 7.1.2 of the ECMAScript Language Specification.

fn coerce_coerce_to_number(&self) -> NapiResult<JsNumber>

This API implements the abstract operation ToNumber() as defined in Section 7.1.3 of the ECMAScript Language Specification. This function potentially runs JS code if the passed-in value is an object.

fn coerce_to_object(&self) -> NapiResult<JsObject>

This API implements the abstract operation ToObject() as defined in Section 7.1.13 of the ECMAScript Language Specification.

fn coerce_to_string(&self) -> NapiResult<JsString>

This API implements the abstract operation ToString() as defined in Section 7.1.13 of the ECMAScript Language Specification. This function potentially runs JS code if the passed-in value is an object.

fn instance_of(&self, constructor: JsFunction) -> NapiResult<bool>

This API represents invoking the instanceof Operator on the object as defined in Section 12.10.4 of the ECMAScript Language Specification.

fn is_array(&self) -> NapiResult<bool>

This API represents invoking the IsArray operation on the object as defined in Section 7.2.2 of the ECMAScript Language Specification.

fn is_arraybuffer(&self) -> NapiResult<bool>

This API checks if the Object passed in is an array buffer.

fn is_buffer(&self) -> NapiResult<bool>

This API checks if the Object passed in is a buffer.

fn is_error(&self) -> NapiResult<bool>

This API checks if the Object passed in is a error.

fn is_typedarray(&self) -> NapiResult<bool>

This API checks if the Object passed in is a typed array.

fn is_dataview(&self) -> NapiResult<bool>

This API checks if the Object passed in is a DataView.

fn equals(&self, rhs: impl NapiValueT) -> NapiResult<bool>

This API represents the invocation of the Strict Equality algorithm as defined in Section 7.2.14 of the ECMAScript Language Specification.

fn kind(&self) -> NapiResult<NapiValuetype>

Returns napi_ok if the API succeeded.

fn env(&self) -> NapiEnv

the NapiEnv of current value

fn raw(&self) -> napi_value

the raw-handle of current value

fn null(&self) -> NapiResult<JsNull>

get null singleton

fn undefined(&self) -> NapiResult<JsUndefined>

get undefined singleton

fn global(&self) -> NapiResult<JsGlobal>

get global singleton

fn throw(&self) -> NapiResult<()>

value is throwable

fn define_properties<P>(&self, properties: P) -> NapiResult<()> where
    P: AsRef<[NapiPropertyDescriptor]>, 

This method allows the efficient definition of multiple properties on a given object. The properties are defined using property descriptors (see napi_property_descriptor). Given an array of such property descriptors, this API will set the properties on the object one at a time, as defined by DefineOwnProperty() (described in Section 9.1.6 of the ECMA-262 specification).

fn gc<Finalizer>(&mut self, finalizer: Finalizer) -> NapiResult<NapiRef> where
    Finalizer: FnOnce(NapiEnv) -> NapiResult<()>, 

This is a hook which is fired when the value is gabage-collected. For napi >= 5, we use napi_add_finalizer, For napi < 5, we use napi_wrap.

fn wrap<T, Finalizer>(
    &mut self,
    data: T,
    finalizer: Finalizer
) -> NapiResult<NapiRef> where
    Finalizer: FnOnce(NapiEnv, T) -> NapiResult<()>, 

Wraps a native instance in a JavaScript object. The native instance can be retrieved later using napi_unwrap().

fn unwrap<T>(&self) -> NapiResult<Option<&T>>

Retrieves a native instance that was previously wrapped in a JavaScript object using napi_wrap().

fn remove_wrap<T>(&mut self) -> NapiResult<T>

Retrieves a native instance that was previously wrapped in the JavaScript object js_object using napi_wrap() and removes the wrapping. If a finalize callback was associated with the wrapping, it will no longer be called when the JavaScript object becomes garbage-collected.

impl Copy for JsClass