1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88

use crate::get_module_from_state;
use rocket::outcome::IntoOutcome;
use rocket::request::{FromRequest, Outcome};
use rocket::{http::Status, Request};
use shaku::{HasProvider, ModuleInterface};
use std::marker::PhantomData;
use std::ops::Deref;

/// Used to create a provided service from a shaku `Module`.
/// The module should be stored in Rocket's state, in a `Box` (It could be
/// `Box<dyn MyModule>` if the module implementation changes at runtime).
/// Use this `InjectProvided` struct as a request guard.
///
/// # Example
/// ```rust
/// #![feature(proc_macro_hygiene, decl_macro)]
///
/// #[macro_use] extern crate rocket;
///
/// use shaku::{module, Provider};
/// use shaku_rocket::InjectProvided;
///
/// trait HelloWorld {
///     fn greet(&self) -> String;
/// }
///
/// #[derive(Provider)]
/// #[shaku(interface = HelloWorld)]
/// struct HelloWorldImpl;
///
/// impl HelloWorld for HelloWorldImpl {
///     fn greet(&self) -> String {
///         "Hello, world!".to_owned()
///     }
/// }
///
/// module! {
///     HelloModule {
///         components = [],
///         providers = [HelloWorldImpl]
///     }
/// }
///
/// #[get("/")]
/// fn hello(hello_world: InjectProvided<HelloModule, dyn HelloWorld>) -> String {
///     hello_world.greet()
/// }
///
/// fn main() {
///     let module = HelloModule::builder().build();
///
/// # if false { // We don't actually want to launch the server in an example.
///     rocket::ignite()
///         .manage(Box::new(module))
///         .mount("/", routes![hello])
///         .launch();
/// # }
/// }
/// ```
pub struct InjectProvided<M: ModuleInterface + HasProvider<I> + ?Sized, I: ?Sized>(
    Box<I>,
    PhantomData<M>,
);

impl<'a, 'r, M: ModuleInterface + HasProvider<I> + ?Sized, I: ?Sized> FromRequest<'a, 'r>
    for InjectProvided<M, I>
{
    type Error = String;

    fn from_request(request: &'a Request<'r>) -> Outcome<Self, Self::Error> {
        let module = get_module_from_state::<M>(request)?;
        let service = module
            .inner()
            .provide()
            .map_err(|e| e.to_string())
            .into_outcome(Status::InternalServerError)?;

        Outcome::Success(InjectProvided(service, PhantomData))
    }
}

impl<M: ModuleInterface + HasProvider<I> + ?Sized, I: ?Sized> Deref for InjectProvided<M, I> {
    type Target = I;

    fn deref(&self) -> &Self::Target {
        self.0.deref()
    }
}