Extract header value

[sergeysova]

    pub mod parameters {
        use actix_web::{FromRequest, HttpRequest};
        use serde::Serialize;

        #[derive(Debug, Serialize, Clone)]
        struct ParseHeaderError {
            error: String,
            message: String,
        }

        fn extract_header(req: &HttpRequest, name: String) -> Result<String, ParseHeaderError> {
            let header_error = ParseHeaderError {
                error: "header_required".to_string(),
                message: format!("header '{}' is required", name),
            };

            let header = req.headers().get(name).ok_or(header_error.clone())?;
            let value = header.to_str().map_err(|_| header_error)?.to_string();
            Ok(value)
        }

        pub struct AccessToken(pub String);

        impl FromRequest for AccessToken {
            type Config = ();
            type Error = actix_web::Error;
            type Future = futures::future::Ready<Result<Self, Self::Error>>;

            #[inline]
            fn from_request(req: &HttpRequest, _: &mut actix_web::dev::Payload) -> Self::Future {
                match extract_header(&req, "X-Access-Token".to_string()) {
                    Ok(value) => futures::future::ok(AccessToken(value)),
                    Err(reason) => match serde_json::to_string(&reason) {
                        Ok(json) => futures::future::err(actix_web::error::ErrorBadRequest(json)),
                        Err(error) => {
                            futures::future::err(actix_web::error::ErrorInternalServerError(error))
                        }
                    },
                }
            }
        }
    }