Struct gotham::pipeline::Pipeline

source · [−]
pub struct Pipeline<T> where
    T: NewMiddlewareChain,  { /* private fields */ }
Expand description

When using middleware, one or more Middleware are combined to form a Pipeline. Middleware are invoked strictly in the order they’re added to the Pipeline.

At Request dispatch time, the Middleware are created from the NewMiddleware values given to the PipelineBuilder, and combined with a Handler created from the NewHandler provided to Pipeline::call. These Middleware and Handler values are used for a single Request.

Examples

#[derive(StateData)]
struct MiddlewareData {
    vec: Vec<i32>
}

#[derive(NewMiddleware, Copy, Clone)]
struct MiddlewareOne;

impl Middleware for MiddlewareOne {
    // Implementation elided.
    // Appends `1` to `MiddlewareData.vec`
}

#[derive(NewMiddleware, Copy, Clone)]
struct MiddlewareTwo;

impl Middleware for MiddlewareTwo {
    // Implementation elided.
    // Appends `2` to `MiddlewareData.vec`
}

#[derive(NewMiddleware, Copy, Clone)]
struct MiddlewareThree;

impl Middleware for MiddlewareThree {
    // Implementation elided.
    // Appends `3` to `MiddlewareData.vec`
}

fn handler(state: State) -> (State, Response<Body>) {
    let body = {
       let data = state.borrow::<MiddlewareData>();
       format!("{:?}", data.vec)
    };

    let res = create_response(&state,
                              StatusCode::OK,
                              mime::TEXT_PLAIN,
                              body);

    (state, res)
}

fn main() {
    let (chain, pipelines) = single_pipeline(
        new_pipeline()
            .add(MiddlewareOne)
            .add(MiddlewareTwo)
            .add(MiddlewareThree)
            .build()
    );

    let router = build_router(chain, pipelines, |route| {
        route.get("/").to(handler);
    });

    let test_server = TestServer::new(router).unwrap();
    let response = test_server.client().get("http://example.com/").perform().unwrap();
    assert_eq!(response.status(), StatusCode::OK);
    assert_eq!(response.read_utf8_body().unwrap(), "[1, 2, 3]");
}

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more

Immutably borrows from an owned value. Read more

Mutably borrows from an owned value. Read more

Returns the argument unchanged.

Instruments this type with the provided Span, returning an Instrumented wrapper. Read more

Instruments this type with the current Span, returning an Instrumented wrapper. Read more

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

The type returned in the event of a conversion error.

Performs the conversion.

The type returned in the event of a conversion error.

Performs the conversion.

Attaches the provided Subscriber to this type, returning a WithDispatch wrapper. Read more

Attaches the current default Subscriber to this type, returning a WithDispatch wrapper. Read more