coi

Dependency Injection in Rust

The goal of this crate is to provide a simple dependency injection framework that is easy to use. Performance is not an initial concern, but might be later on as the crate matures.

Example

```rust use coi::{container, Inject}; use std::sync::Arc;

// Inherit Inject on all traits you'd like to inject pub trait Trait1: Inject { fn describe(&self) -> &'static str; }

// derive Inject on all structs that will provide the implementation

[derive(Inject)]

[coi(provides dyn Trait1 with Impl1)]

struct Impl1;

// actually impl the trait impl Trait1 for Impl1 { fn describe(&self) -> &'static str { "I'm impl1!" } }

pub trait Trait2: Inject { fn deep_describe(&self) -> String; }

[derive(Inject)]

[coi(provides dyn Trait2 with Impl2::new(trait1))]

struct Impl2 { // inject dependencies by Arc #[coi(inject)] trait1: Arc, }

impl Impl2 { fn new(trait1: Arc) -> Self { Self { trait1 } } }

impl Trait2 for Impl2 { fn deep_describe(&self) -> String { format!("I'm impl2! and I have {}", self.trait1.describe()) } }

// It even works on structs

[derive(Debug, Inject)]

[coi(provides JustAStruct with JustAStruct)]

pub struct JustAStruct;

fn main() { // Then construct your container with the helper container! macro let container = container!{ trait1 => Impl1Provider, trait2 => Impl2Provider; scoped, struct => JustAStructProvider; singleton };

// And resolve away!
let trait2 = container
    .resolve::<dyn Trait2>("trait2")
    .expect("Should exist");
println!("Deep description: {}", trait2.as_ref().deep_describe());
let a_struct = container
    .resolve::<JustAStruct>("struct")
    .expect("Should exist");
println!("Got struct! {:?}", a_struct);

} ```

Name

The name coi comes from an inversion of the initialism IoC (Inversion of Control).

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