seamless/handler/
response.rs

1use crate::api::{ ApiBody, ApiBodyInfo, ApiError };
2use async_trait::async_trait;
3use serde::Serialize;
4
5type HttpResponse = http::Response<Vec<u8>>;
6
7/// Anything that you'd like to be able to return from a handler function must implement
8/// this trait, which decides how to take the result of a handler function and encode it
9/// into an [`http::Response<Vec<u8>>`], or failing to do so, returns an [`struct@ApiError`].
10#[async_trait]
11pub trait HandlerResponse {
12    /// The type that we should look at to work out what the response body will look like.
13    type ResponseBody: ApiBody;
14    /// This describes how the type can be converted into an `http::Response`.
15    async fn handler_response(self) -> Result<HttpResponse, ApiError>;
16}
17
18/// Wrap responses in this to return them as JSON
19pub struct ToJson<T: ApiBody>(pub T);
20
21#[async_trait]
22impl <T: ApiBody + Serialize + Send> HandlerResponse for ToJson<T> {
23    type ResponseBody = T;
24    async fn handler_response(self) -> Result<HttpResponse, ApiError> {
25        let body = serde_json::to_vec(&self.0).unwrap();
26        let res = http::Response::builder()
27            .header("content-type", "application/json")
28            .body(body)
29            .unwrap();
30        Ok(res)
31    }
32}
33
34impl <T> ApiBody for ToJson<T> where T: ApiBody {
35    fn api_body_info() -> ApiBodyInfo {
36        T::api_body_info()
37    }
38}
39
40// Options are valid HandlerResponse's if their T's are
41#[async_trait]
42impl <T> HandlerResponse for Option<T>
43where
44    T: HandlerResponse + Send
45{
46    type ResponseBody = <T as HandlerResponse>::ResponseBody;
47    async fn handler_response(self) -> Result<HttpResponse, ApiError> {
48        let res = self.ok_or_else(|| ApiError::path_not_found())?;
49        res.handler_response().await.map_err(|e| e.into())
50    }
51}
52
53// Results are valid HandlerResponse's if their T's are, and their E's convert to ApiError
54#[async_trait]
55impl <T, E> HandlerResponse for Result<T,E>
56where
57    T: HandlerResponse + Send,
58    E: Into<ApiError> + Send + 'static,
59{
60    type ResponseBody = <T as HandlerResponse>::ResponseBody;
61    async fn handler_response(self) -> Result<HttpResponse, ApiError> {
62        let res = self.map_err(|e| e.into())?;
63        res.handler_response().await.map_err(|e| e.into())
64    }
65}
66
seamless/handler/response.rs

seamless/handler/
response.rs
