1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266

//! Types and traits for generating responses.

use crate::Body;
use bytes::Bytes;
use http::{header, HeaderMap, HeaderValue, Response, StatusCode};
use serde::Serialize;
use std::{borrow::Cow, convert::Infallible};
use tower::util::Either;

/// Trait for generating responses.
///
/// Types that implement `IntoResponse` can be returned from handlers.
pub trait IntoResponse {
    /// Create a response.
    fn into_response(self) -> Response<Body>;
}

impl IntoResponse for () {
    fn into_response(self) -> Response<Body> {
        Response::new(Body::empty())
    }
}

impl IntoResponse for Infallible {
    fn into_response(self) -> Response<Body> {
        match self {}
    }
}

impl<T, K> IntoResponse for Either<T, K>
where
    T: IntoResponse,
    K: IntoResponse,
{
    fn into_response(self) -> Response<Body> {
        match self {
            Either::A(inner) => inner.into_response(),
            Either::B(inner) => inner.into_response(),
        }
    }
}

impl<T, E> IntoResponse for Result<T, E>
where
    T: IntoResponse,
    E: IntoResponse,
{
    fn into_response(self) -> Response<Body> {
        match self {
            Ok(value) => value.into_response(),
            Err(err) => err.into_response(),
        }
    }
}

impl IntoResponse for Response<Body> {
    fn into_response(self) -> Self {
        self
    }
}

impl IntoResponse for Body {
    fn into_response(self) -> Response<Body> {
        Response::new(self)
    }
}

impl IntoResponse for &'static str {
    #[inline]
    fn into_response(self) -> Response<Body> {
        Cow::Borrowed(self).into_response()
    }
}

impl IntoResponse for String {
    #[inline]
    fn into_response(self) -> Response<Body> {
        Cow::<'static, str>::Owned(self).into_response()
    }
}

impl IntoResponse for std::borrow::Cow<'static, str> {
    fn into_response(self) -> Response<Body> {
        let mut res = Response::new(Body::from(self));
        res.headers_mut()
            .insert(header::CONTENT_TYPE, HeaderValue::from_static("text/plain"));
        res
    }
}

impl IntoResponse for Bytes {
    fn into_response(self) -> Response<Body> {
        let mut res = Response::new(Body::from(self));
        res.headers_mut().insert(
            header::CONTENT_TYPE,
            HeaderValue::from_static("application/octet-stream"),
        );
        res
    }
}

impl IntoResponse for &'static [u8] {
    fn into_response(self) -> Response<Body> {
        let mut res = Response::new(Body::from(self));
        res.headers_mut().insert(
            header::CONTENT_TYPE,
            HeaderValue::from_static("application/octet-stream"),
        );
        res
    }
}

impl IntoResponse for Vec<u8> {
    fn into_response(self) -> Response<Body> {
        let mut res = Response::new(Body::from(self));
        res.headers_mut().insert(
            header::CONTENT_TYPE,
            HeaderValue::from_static("application/octet-stream"),
        );
        res
    }
}

impl IntoResponse for std::borrow::Cow<'static, [u8]> {
    fn into_response(self) -> Response<Body> {
        let mut res = Response::new(Body::from(self));
        res.headers_mut().insert(
            header::CONTENT_TYPE,
            HeaderValue::from_static("application/octet-stream"),
        );
        res
    }
}

impl IntoResponse for StatusCode {
    fn into_response(self) -> Response<Body> {
        Response::builder()
            .status(self)
            .body(Body::empty())
            .unwrap()
    }
}

impl<T> IntoResponse for (StatusCode, T)
where
    T: IntoResponse,
{
    fn into_response(self) -> Response<Body> {
        let mut res = self.1.into_response();
        *res.status_mut() = self.0;
        res
    }
}

impl<T> IntoResponse for (HeaderMap, T)
where
    T: IntoResponse,
{
    fn into_response(self) -> Response<Body> {
        let mut res = self.1.into_response();
        *res.headers_mut() = self.0;
        res
    }
}

impl<T> IntoResponse for (StatusCode, HeaderMap, T)
where
    T: IntoResponse,
{
    fn into_response(self) -> Response<Body> {
        let mut res = self.2.into_response();
        *res.status_mut() = self.0;
        *res.headers_mut() = self.1;
        res
    }
}

impl IntoResponse for HeaderMap {
    fn into_response(self) -> Response<Body> {
        let mut res = Response::new(Body::empty());
        *res.headers_mut() = self;
        res
    }
}

/// An HTML response.
///
/// Will automatically get `Content-Type: text/html`.
#[derive(Clone, Copy, Debug)]
pub struct Html<T>(pub T);

impl<T> IntoResponse for Html<T>
where
    T: Into<Body>,
{
    fn into_response(self) -> Response<Body> {
        let mut res = Response::new(self.0.into());
        res.headers_mut()
            .insert(header::CONTENT_TYPE, HeaderValue::from_static("text/html"));
        res
    }
}

impl<T> From<T> for Html<T> {
    fn from(inner: T) -> Self {
        Self(inner)
    }
}

/// A JSON response.
///
/// Can be created from any type that implements [`serde::Serialize`].
///
/// Will automatically get `Content-Type: application/json`.
///
/// # Example
///
/// ```
/// use serde_json::json;
/// use axum::{body::Body, response::{Json, IntoResponse}};
/// use http::{Response, header::CONTENT_TYPE};
///
/// let json = json!({
///     "data": 42,
/// });
///
/// let response: Response<Body> = Json(json).into_response();
///
/// assert_eq!(
///     response.headers().get(CONTENT_TYPE).unwrap(),
///     "application/json",
/// );
/// ```
#[derive(Clone, Copy, Debug)]
pub struct Json<T>(pub T);

impl<T> IntoResponse for Json<T>
where
    T: Serialize,
{
    fn into_response(self) -> Response<Body> {
        let bytes = match serde_json::to_vec(&self.0) {
            Ok(res) => res,
            Err(err) => {
                return Response::builder()
                    .status(StatusCode::INTERNAL_SERVER_ERROR)
                    .header(header::CONTENT_TYPE, "text/plain")
                    .body(Body::from(err.to_string()))
                    .unwrap();
            }
        };

        let mut res = Response::new(Body::from(bytes));
        res.headers_mut().insert(
            header::CONTENT_TYPE,
            HeaderValue::from_static("application/json"),
        );
        res
    }
}

impl<T> From<T> for Json<T> {
    fn from(inner: T) -> Self {
        Self(inner)
    }
}