rust - 从Actix Web处理程序返回HTML或JSON

Question

我希望我的所有路线都可以在请求时返回Json而不是HTML。
例如，当请求/index.json时，它应返回将生成/index html响应的对象。
我目前正在第11行的路由宏中使用“尾部匹配”来处理此问题:

  5 #[derive(Serialize)]
  6 struct FollowerPresenter {
  7     follower_name: String,
  8     followee_name: String,
  9 }
 10
 11 #[get("/index{tail:.*}")]
 12 async fn index(
 13     mime: web::Path<String>,
 14     template: web::Data<tera::Tera>,
 15 ) -> Result<HttpResponse, Error> {
 16     let presenter = FollowerPresenter {
 17         follower_name: "Jill".into(),
 18         followee_name: "Jim".into(),
 19     };
 20
 21     match mime.as_str() {
 22         "" | "/" => {
 23             let body = template
 24                 .render("index.html", &Context::from_serialize(&presenter).unwrap())
 25                 .map_err(|_| error::ErrorInternalServerError("Template error"))?;
 26
 27             Ok(HttpResponse::Ok().content_type("text/html").body(body))
 28         }
 29         ".json" => Ok(HttpResponse::Ok().json(presenter)),
 30         _ => Err(error::ErrorNotFound("Resource Not Found")),
 31     }
 32 }
 33
 34 #[actix_web::main]
 35 async fn main() -> std::io::Result<()> {
 36     HttpServer::new(|| {
 37         let tera = Tera::new(concat!(env!("CARGO_MANIFEST_DIR"), "/src/views/**/*")).unwrap();
 38
 39         App::new().data(tera).service(index)
 40     })
 41     .bind("127.0.0.1:3000")?
 42     .run()
 43     .await
 44 }

必须有一种使用中间件之类的方法来避免将整个控制结构放在每个处理程序的第21-30行中。

Answer 1

好了，您的问题(以及我的答案)也取决于req.query("tail")，可以通过检查url本身(可以在其中使用str::ends_with)进行改进。
这是一个基于Responder的工作解决方案。

use actix_http::{Error, Response};
use actix_web::*;
use futures_util::future::{err, ok, Ready};
use serde::Serialize;
use tera::{Context, Tera};

struct MyResponder<P: Serialize, T: Into<String>> {
    presenter: P,
    template: T,
}

impl<P: Serialize, T: Into<String>> Responder for MyResponder<P, T> {
    type Error = Error;
    type Future = Ready<Result<Response, Error>>;

    fn respond_to(self, req: &HttpRequest) -> Self::Future {
        let mime = req.match_info().query("tail");
        let template = req.app_data::<web::Data<tera::Tera>>().unwrap();
        let presenter = serde_json::to_value(&self.presenter).unwrap();
        match mime {
            "" | "/" => {
                let body = template
                    .render(
                        &self.template.into(),
                        &Context::from_serialize(&presenter).unwrap(),
                    )
                    .unwrap();
                ok(HttpResponse::Ok().content_type("text/html").body(body))
            }
            ".json" => ok(HttpResponse::Ok().json(&presenter)),
            _ => err(error::ErrorNotFound("Resource Not Found")),
        }
    }
}

#[derive(Serialize)]
struct FollowerPresenter {
    follower_name: String,
    followee_name: String,
}

#[get("/index{tail:.*}")]
async fn index() -> impl Responder {
    let presenter = FollowerPresenter {
        follower_name: "Jill".into(),
        followee_name: "Jim".into(),
    };

    MyResponder {
        presenter,
        template: "index.html",
    }
}

#[actix_web::main]
async fn main() -> std::io::Result<()> {
    HttpServer::new(|| {
        let tera = Tera::new(concat!(env!("CARGO_MANIFEST_DIR"), "/src/views/**/*")).unwrap();
        App::new().data(tera).service(index)
    })
    .bind("127.0.0.1:3000")?
    .run()
    .await
}

#[cfg(test)]
mod tests {
    use super::*;
    use actix_web::{body::Body, test, App};
    use serde_json::json;

    #[actix_rt::test]
    async fn test_json_get() {
        let tera = Tera::new(concat!(env!("CARGO_MANIFEST_DIR"), "/src/views/**/*")).unwrap();
        let mut app = test::init_service(App::new().data(tera).service(index)).await;
        let req = test::TestRequest::with_uri("/index.json").to_request();
        let mut resp = test::call_service(&mut app, req).await;
        let body = resp.take_body();
        let body = body.as_ref().unwrap();
        assert!(resp.status().is_success());
        assert_eq!(
            &Body::from(json!({"follower_name":"Jill", "followee_name": "Jim" })), // or serde.....
            body
        );
    }
    #[actix_rt::test]
    #[should_panic] /// Template doesnt exist
    async fn test_web_get() {
        let tera = Tera::new(concat!(env!("CARGO_MANIFEST_DIR"), "/src/views/**/*")).unwrap();
        let mut app = test::init_service(App::new().data(tera).service(index)).await;
        let req = test::TestRequest::with_uri("/index").to_request();
        let _resp = test::call_service(&mut app, req).await;

    }
}

运行测试得出:

running 2 tests
test tests::test_json_get ... ok
test tests::test_web_get ... ok

test result: ok. 2 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out