coi-actix-web-derive

Provides derives for coi-actix-web


Licenses
MIT/Apache-2.0

Documentation

coi-actix-web

Build Status docs.rs crates.io

Dependency Injection in Rust

This crate provides integration support between coi and actix-web version 4. It exposes an inject procedural attribute macro to generate the code for retrieving your dependencies from a Container registered with actix-web.

Example

// What this crate provides
use coi_actix_web::inject;

// What's needed for the example fn below
use actix_web::{get, web, Error, HttpResponse, Responder};
use std::sync::Arc;

// Add the `inject` attribute to the function you want to inject
#[get("/{id}")]
#[coi_actix_web::inject]
async fn get(
    id: web::Path<u64>,
    // Add the `inject` field attribute to each attribute you want
    // injected
    #[inject] service: Arc<dyn IService>
) -> Result<impl Responder, Error> {
    let data = service.get(*id).await?;
    Ok(HttpResponse::Ok().json(DataDto::from(data)))
}

// Just data models for the above fn
use serde::Serialize;

#[derive(Serialize)]
struct DataDto {
    name: String,
}

impl DataDto {
    fn from(data: Data) -> Self {
        Self {
            name: data.name
        }
    }
}


// An example of what's usually needed to make effective use of this
// crate is below
use actix_web::ResponseError;
use coi::Inject;
use futures::future::{ready, BoxFuture};
use futures::FutureExt;

// This section shows coi being put to use
// It's very important that the version of coi and the version
// of coi-actix-web used match since coi-actix-web implements
// some coi traits

#[derive(Debug)]
enum ServiceError {
    Repo(RepoError),
}

impl ResponseError for ServiceError {}

impl From<RepoError> for ServiceError {
    fn from(err: RepoError) -> Self {
        Self::Repo(err)
    }
}

impl std::fmt::Display for ServiceError {
    fn fmt(&self, f: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> {
        match self {
            ServiceError::Repo(r) => write!(f, "Repo({})", r),
        }
    }
}

// Here we're marking a trait as injectable
trait IService: Inject {
    fn get(&self, id: u64) -> BoxFuture<Result<Data, ServiceError>>;
}

// And here we're marking a type that's capable of providing the
// above trait
#[derive(Inject)]
#[coi(provides dyn IService with ServiceImpl::new(repo))]
struct ServiceImpl {
    // Here we're injecting a dependency. `ServiceImpl` does
    // not need to know how to get this value.
    #[coi(inject)]
    repo: Arc<dyn IRepo>
}

// Normal impl for struct
impl ServiceImpl {
    fn new(repo: Arc<dyn IRepo>) -> Self {
        Self { repo }
    }
}

// Normal impl of trait for struct
impl IService for ServiceImpl {
    fn get(&self, id: u64) -> BoxFuture<Result<Data, ServiceError>> {
        async move {
            let data = self.repo.read_from_db(id).await?;
            Ok(data)
        }.boxed()
    }
}

// The data that will be passed between services
struct Data {
    id: u64,
    name: String,
}

#[derive(Debug)]
struct RepoError;
impl ResponseError for RepoError {}

impl std::fmt::Display for RepoError {
    fn fmt(&self, f: &mut std::fmt::Formatter)  -> Result<(), std::fmt::Error> {
        write!(f, "RepoError")
    }
}

// Here's the trait from above
trait IRepo: Inject {
    fn read_from_db(&self, id: u64) -> BoxFuture<Result<Data, RepoError>>;
}

// And it's setup below
#[derive(Inject)]
#[coi(provides dyn IRepo with RepoImpl)]
struct RepoImpl;

impl IRepo for RepoImpl {
    fn read_from_db(&self, id: u64) -> BoxFuture<Result<Data, RepoError>> {
        Box::pin(ready(Ok(Data {
            id,
            name: format!("{}'s name...", id)
        })))
    }
}

// This is for the register_container function
use coi_actix_web::AppExt as _;

// Your general server setup in "main". The name here is different
#[actix_rt::main]
async fn main() -> std::io::Result<()> {
    use actix_web::{App, HttpServer};
    use coi::container;

    // Construct your coi container with your keys and providers
    // See the coi crate for more details
    let container = container!{
        repo => RepoImplProvider; scoped,
        service => ServiceImplProvider; scoped
    };

    HttpServer::new(move || {
        App::new()
        // Don't forget to register the container or else
        // the injections will fail on every request!
        .register_container(container.clone())
        .service(get)
    })
    .bind("127.0.0.1:8000")?
    .run()
    .await
}

See the repo coi-actix-sample for a more involved example.

License

Licensed under either of Apache License, Version 2.0 or MIT license at your option.
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in this crate by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.

SPDX-License-Identifier: MIT OR Apache-2.0