[−][src]Trait roa_core::Model

pub trait Model: 'static + Send + Sync + Sized {
    type State: State;
    fn new_state(&self) -> Self::State;
}

The Model trait. The new_state method will be called when a request inbound.

Model and its State is designed to share data or handler between middlewares. The only one type implemented Model by this crate is (), you should implement your custom Model if neccassary.

Example

use roa_core::{App, Model};
use log::info;
use async_std::task::spawn;
use http::StatusCode;

struct AppModel {
    default_id: u64,
}

struct AppState {
    id: u64,
}

impl AppModel {
    fn new() -> Self {
        Self {
            default_id: 0,
        }
    }
}

impl Model for AppModel {
    type State = AppState;
    fn new_state(&self) -> Self::State {
        AppState {
            id: self.default_id,
        }
    }
}

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let (addr, server) = App::new(AppModel::new())
        .gate_fn(|ctx, next| async move {
            ctx.state_mut().await.id = 1;
            next().await
        })
        .end(|ctx| async move {
            let id = ctx.state().await.id;
            assert_eq!(1, id);
            Ok(())
        })
        .run_local()?;
    spawn(server);
    let resp = reqwest::get(&format!("http://{}", addr)).await?;
    assert_eq!(StatusCode::OK, resp.status());
    Ok(())
}

Associated Types

type State: State

State type of this model.

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Required methods

fn new_state(&self) -> Self::State

Construct a new state instance.

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Implementations on Foreign Types

impl Model for ()[src]

type State = ()

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Implementors

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