Unable to set headers on Response

[Jonathan Pettersson]

Hi,

I'm trying to set headers based on the enable_cors.rs example, but I run into a type error. I've tried various combinations of rustc, hyper and nickel versions, but they all yield the same error:

src/main.rs:13:13: 13:16 error: the trait bound `hyper::header::AccessControlAllowOrigin: modifier::Modifier<nickel::Response<'_>>` is not satisfied [E0277]
src/main.rs:13         res.set(AccessControlAllowOrigin::Any);

My implementation looks like this:

#[macro_use] extern crate nickel;
extern crate hyper;
extern crate rustc_serialize;

use nickel::{Nickel, HttpRouter, Request, Response, MiddlewareResult};
use hyper::header::{AccessControlAllowOrigin, AccessControlAllowHeaders, Location};
use rustc_serialize::json::{ToJson};

fn main() {
    let mut server = Nickel::new();

    fn enable_cors<'mw>(_req: &mut Request, mut res: Response<'mw>) -> MiddlewareResult<'mw> {
        res.set(AccessControlAllowOrigin::Any);
        res.next_middleware()
    }

    server.utilize(enable_cors);

    server.get("/v0/graphs", middleware!{ |_|
        "hello".to_string().to_json()
    });

    server.listen("127.0.0.1:6767");
}

Dependencies:

[dependencies]
nickel = "0.8.1"
rustc-serialize = "0.3.19"

[dependencies.hyper]
version = "0.9"
default-features = false

I'm guessing I've missed something obvious.. any ideas?

Thanks!

[Jonathan Pettersson]

I found an old issue which describes the same problem: #221

Seems it's a Cargo dependency resolution issue. I managed to work around it for now by setting raw headers like this:

res.headers_mut().set_raw("Access-Control-Allow-Origin", vec![b"*".to_vec()]);
res.headers_mut().set_raw("Access-Control-Allow-Headers", vec![b"Origin X-Requested-With Content-Type Accept".to_vec()]);

[Matthew Knight]

It seems in my project I had to import hyper::header::Headers as well as the actual header. Does that make any difference?

[Roberto Huertas]

You can see a working example in #426

[Jeff Olhoeft]

Closing as we now have a working CORS example. Please re-open if there are still issues.