Struct neon::types::JsPromise

#[repr(transparent)]
pub struct JsPromise(_);

The JavaScript Promise value.

JsPromise may be constructed with Context::promise.

Implementations

impl JsPromise

pub fn resolve<'a, C: Context<'a>, T: Value>(
    cx: &mut C,
    value: Handle<'_, T>
) -> Handle<'a, Self>

Creates a new Promise immediately resolved with the given value. If the value is a Promise or a then-able, it will be flattened.

JsPromise::resolve is useful to ensure a value that might not be a Promise or might not be a native promise is converted to a Promise before use.

pub fn reject<'a, C: Context<'a>, E: Value>(
    cx: &mut C,
    err: Handle<'_, E>
) -> Handle<'a, Self>

Creates a nwe Promise immediately rejected with the given error.

pub fn to_future<'a, O, C, F>(&self, cx: &mut C, f: F) -> NeonResult<JsFuture<O>> where
    O: Send + 'static,
    C: Context<'a>,
    F: FnOnce(TaskContext<'_>, Result<Handle<'_, JsValue>, Handle<'_, JsValue>>) -> NeonResult<O> + Send + 'static, 

Available on crate features napi-5 and futures only.

Creates a Future that can be awaited to receive the result of a JavaScript Promise.

A callback must be provided that maps a Result representing the resolution or rejection of the Promise and returns a value as the Future output.

Note: Unlike Future, Promise are eagerly evaluated and so are JsFuture.

Trait Implementations

impl Debug for JsPromise

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

Formats the value using the given formatter.

impl Managed for JsPromise

fn to_raw(&self) -> *mut Value__

fn from_raw(_env: Env, h: *mut Value__) -> Self

impl Object for JsPromise

fn get_opt<'a, V: Value, C: Context<'a>, K: PropertyKey>(
    &self,
    cx: &mut C,
    key: K
) -> NeonResult<Option<Handle<'a, V>>>

Gets a property from a JavaScript object that may be undefined and attempts to downcast the value if it existed.

fn get_value<'a, C: Context<'a>, K: PropertyKey>(
    &self,
    cx: &mut C,
    key: K
) -> NeonResult<Handle<'a, JsValue>>

Gets a property from a JavaScript object as a JsValue.

fn get<'a, V: Value, C: Context<'a>, K: PropertyKey>(
    &self,
    cx: &mut C,
    key: K
) -> NeonResult<Handle<'a, V>>

Gets a property from a JavaScript object and attempts to downcast as a specific type. Equivalent to calling obj.get_value(&mut cx)?.downcast_or_throw(&mut cx).

fn get_own_property_names<'a, C: Context<'a>>(
    &self,
    cx: &mut C
) -> JsResult<'a, JsArray>

Available on crate feature napi-6 only.

fn freeze<'a, C: Context<'a>>(&self, cx: &mut C) -> NeonResult<&Self>

fn seal<'a, C: Context<'a>>(&self, cx: &mut C) -> NeonResult<&Self>

fn set<'a, C: Context<'a>, K: PropertyKey, W: Value>(
    &self,
    cx: &mut C,
    key: K,
    val: Handle<'_, W>
) -> NeonResult<bool>

fn root<'a, C: Context<'a>>(&self, cx: &mut C) -> Root<Self>

fn call_method_with<'a, C, K>(
    &self,
    cx: &mut C,
    method: K
) -> NeonResult<CallOptions<'a>> where
    C: Context<'a>,
    K: PropertyKey, 

impl Value for JsPromise

fn to_string<'a, C: Context<'a>>(&self, cx: &mut C) -> JsResult<'a, JsString>

fn as_value<'a, C: Context<'a>>(&self, _: &mut C) -> Handle<'a, JsValue>