Struct neon::types::Deferred

pub struct Deferred { /* private fields */ }

A controller struct that can be used to resolve or reject a JsPromise.

It is recommended to settle a Deferred with Deferred::settle_with to ensure exceptions are caught.

On Node-API versions less than 6, dropping a Deferred without settling will cause a panic. On Node-API 6+, the associated JsPromise will be automatically rejected.

Examples

See JsPromise, JsFuture.

Implementations

impl Deferred

pub fn resolve<'a, V, C>(self, cx: &mut C, value: Handle<'_, V>)

where V: Value, C: Context<'a>,

Resolve a JsPromise with a JavaScript value

pub fn reject<'a, V, C>(self, cx: &mut C, value: Handle<'_, V>)

where V: Value, C: Context<'a>,

Reject a JsPromise with a JavaScript value

pub fn try_settle_with<V, F>( self, channel: &Channel, complete: F ) -> Result<JoinHandle<()>, SendError>

where V: Value, F: FnOnce(TaskContext<'_>) -> JsResult<'_, V> + Send + 'static,

Available on crate feature napi-4 only.

Settle the JsPromise by sending a closure across a Channel to be executed on the main JavaScript thread.

Usage is identical to Deferred::settle_with.

Returns a SendError if sending the closure to the main JavaScript thread fails. See Channel::try_send for more details.

pub fn settle_with<V, F>(self, channel: &Channel, complete: F) -> JoinHandle<()>

where V: Value, F: FnOnce(TaskContext<'_>) -> JsResult<'_, V> + Send + 'static,

Available on crate feature napi-4 only.

Settle the JsPromise by sending a closure across a Channel to be executed on the main JavaScript thread.

Panics if there is a libuv error.

let channel = cx.channel();
let (deferred, promise) = cx.promise();

deferred.settle_with(&channel, move |mut cx| Ok(cx.number(42)));

Trait Implementations

impl Drop for Deferred

fn drop(&mut self)

Executes the destructor for this type.