dioxus_document/
eval.rs

1#![doc = include_str!("../docs/eval.md")]
2
3use crate::error::EvalError;
4use generational_box::GenerationalBox;
5use std::future::{poll_fn, Future, IntoFuture};
6use std::pin::Pin;
7use std::task::{Context, Poll};
8
9#[doc = include_str!("../docs/eval.md")]
10pub struct Eval {
11    evaluator: GenerationalBox<Box<dyn Evaluator>>,
12}
13
14impl Eval {
15    /// Create this eval from a dynamic evaluator
16    pub fn new(evaluator: GenerationalBox<Box<dyn Evaluator + 'static>>) -> Self {
17        Self { evaluator }
18    }
19
20    /// Wait until the javascript task is finished and return the result
21    pub async fn join<T: serde::de::DeserializeOwned>(self) -> Result<T, EvalError> {
22        let json_value = poll_fn(|cx| match self.evaluator.try_write() {
23            Ok(mut evaluator) => evaluator.poll_join(cx),
24            Err(_) => Poll::Ready(Err(EvalError::Finished)),
25        })
26        .await?;
27        serde_json::from_value(json_value).map_err(EvalError::Serialization)
28    }
29
30    /// Send a message to the javascript task
31    pub fn send(&self, data: impl serde::Serialize) -> Result<(), EvalError> {
32        match self.evaluator.try_read() {
33            Ok(evaluator) => {
34                evaluator.send(serde_json::to_value(data).map_err(EvalError::Serialization)?)
35            }
36            Err(_) => Err(EvalError::Finished),
37        }
38    }
39
40    /// Receive a message from the javascript task
41    pub async fn recv<T: serde::de::DeserializeOwned>(&mut self) -> Result<T, EvalError> {
42        let json_value = poll_fn(|cx| match self.evaluator.try_write() {
43            Ok(mut evaluator) => evaluator.poll_recv(cx),
44            Err(_) => Poll::Ready(Err(EvalError::Finished)),
45        })
46        .await?;
47        serde_json::from_value(json_value).map_err(EvalError::Serialization)
48    }
49}
50
51impl IntoFuture for Eval {
52    type Output = Result<serde_json::Value, EvalError>;
53    type IntoFuture = Pin<Box<dyn Future<Output = Self::Output>>>;
54
55    fn into_future(self) -> Self::IntoFuture {
56        Box::pin(self.join().into_future())
57    }
58}
59
60/// The platform's evaluator.
61pub trait Evaluator {
62    /// Sends a message to the evaluated JavaScript.
63    fn send(&self, data: serde_json::Value) -> Result<(), EvalError>;
64    /// Receive any queued messages from the evaluated JavaScript.
65    fn poll_recv(
66        &mut self,
67        context: &mut Context<'_>,
68    ) -> Poll<Result<serde_json::Value, EvalError>>;
69    /// Gets the return value of the JavaScript
70    fn poll_join(
71        &mut self,
72        context: &mut Context<'_>,
73    ) -> Poll<Result<serde_json::Value, EvalError>>;
74}
dioxus_document/eval.rs

dioxus_document/
eval.rs
