docs(server): show JSON deserialization in API example (#1791)

The previous version only showed a JSON GET API. Deserializing the body of a POST request is not trivial so the example should show it. The new example takes the JSON body sent in a POST request, deserializes it, adds a field, then serializes it and sends it back. Signed-off-by: Ole Herman Schumacher Elgesem <[email protected]>
hyperium · Apr 9, 2019 · b3deb0c · b3deb0c
1 parent 2ef562a
commit b3deb0c
Showing 1 changed file with 71 additions and 64 deletions.
diff --git a/examples/web_api.rs b/examples/web_api.rs
@@ -10,80 +10,88 @@ use hyper::{Body, Chunk, Client, Method, Request, Response, Server, StatusCode,
 use hyper::client::HttpConnector;
 use hyper::service::service_fn;
 
-#[allow(unused, deprecated)]
-use std::ascii::AsciiExt;
-
 static NOTFOUND: &[u8] = b"Not Found";
-static URL: &str = "http://127.0.0.1:1337/web_api";
+static URL: &str = "http://127.0.0.1:1337/json_api";
 static INDEX: &[u8] = b"<a href=\"test.html\">test.html</a>";
-static LOWERCASE: &[u8] = b"i am a lower case string";
+static POST_DATA: &str = r#"{"original": "data"}"#;
+
+type GenericError = Box<dyn std::error::Error + Send + Sync>;
+type ResponseFuture = Box<Future<Item=Response<Body>, Error=GenericError> + Send>;
+
+fn client_request_response(client: &Client<HttpConnector>) -> ResponseFuture {
+     let req = Request::builder()
+         .method(Method::POST)
+         .uri(URL)
+         .header(header::CONTENT_TYPE, "application/json")
+         .body(POST_DATA.into())
+         .unwrap();
+
+     Box::new(client.request(req).from_err().map(|web_res| {
+         // Compare the JSON we sent (before) with what we received (after):
+         let body = Body::wrap_stream(web_res.into_body().map(|b| {
+             Chunk::from(format!("<b>POST request body</b>: {}<br><b>Response</b>: {}",
+                                 POST_DATA,
+                                 std::str::from_utf8(&b).unwrap()))
+         }));
+
+         Response::new(body)
+     }))
+}
+
+fn api_post_response(req: Request<Body>) -> ResponseFuture {
+    // A web api to run against
+    Box::new(req.into_body()
+        .concat2() // Concatenate all chunks in the body
+        .from_err()
+        .and_then(|entire_body| {
+            // TODO: Replace all unwraps with proper error handling
+            let str = String::from_utf8(entire_body.to_vec())?;
+            let mut data : serde_json::Value = serde_json::from_str(&str)?;
+            data["test"] = serde_json::Value::from("test_value");
+            let json = serde_json::to_string(&data)?;
+            let response = Response::builder()
+                .status(StatusCode::OK)
+                .header(header::CONTENT_TYPE, "application/json")
+                .body(Body::from(json))?;
+            Ok(response)
+        })
+    )
+}
 
-fn response_examples(req: Request<Body>, client: &Client<HttpConnector>)
-    -> Box<Future<Item=Response<Body>, Error=hyper::Error> + Send>
-{
+fn api_get_response() -> ResponseFuture {
+    let data = vec!["foo", "bar"];
+    let res = match serde_json::to_string(&data) {
+        Ok(json) => {
+            Response::builder()
+                .header(header::CONTENT_TYPE, "application/json")
+                .body(Body::from(json))
+                .unwrap()
+        }
+        Err(_) => {
+            Response::builder()
+                .status(StatusCode::INTERNAL_SERVER_ERROR)
+                .body(Body::from("Internal Server Error"))
+                .unwrap()
+        }
+    };
+
+    Box::new(future::ok(res))
+}
+
+fn response_examples(req: Request<Body>, client: &Client<HttpConnector>) -> ResponseFuture {
     match (req.method(), req.uri().path()) {
         (&Method::GET, "/") | (&Method::GET, "/index.html") => {
             let body = Body::from(INDEX);
             Box::new(future::ok(Response::new(body)))
         },
         (&Method::GET, "/test.html") => {
-            // Run a web query against the web api below
-
-            // build the request
-            let req = Request::builder()
-                .method(Method::POST)
-                .uri(URL)
-                .body(LOWERCASE.into())
-                .unwrap();
-            // use the request with client
-            let web_res_future = client.request(req);
-
-            Box::new(web_res_future.map(|web_res| {
-                // return the response that came from the web api and the original text together
-                // to show the difference
-                let body = Body::wrap_stream(web_res.into_body().map(|b| {
-                    Chunk::from(format!("<b>before</b>: {}<br><b>after</b>: {}",
-                                        std::str::from_utf8(LOWERCASE).unwrap(),
-                                        std::str::from_utf8(&b).unwrap()))
-                }));
-
-                Response::new(body)
-            }))
+           client_request_response(client)
         },
-        (&Method::POST, "/web_api") => {
-            // A web api to run against. Uppercases the body and returns it back.
-            let body = Body::wrap_stream(req.into_body().map(|chunk| {
-                // uppercase the letters
-                let upper = chunk.iter().map(|byte| byte.to_ascii_uppercase())
-                    .collect::<Vec<u8>>();
-                Chunk::from(upper)
-            }));
-            Box::new(future::ok(Response::new(body)))
+        (&Method::POST, "/json_api") => {
+            api_post_response(req)
         },
-        (&Method::GET, "/json") => {
-            let data = vec!["foo", "bar"];
-            let res = match serde_json::to_string(&data) {
-                Ok(json) => {
-                    // return a json response
-                    Response::builder()
-                        .header(header::CONTENT_TYPE, "application/json")
-                        .body(Body::from(json))
-                        .unwrap()
-                }
-                // This is unnecessary here because we know
-                // this can't fail. But if we were serializing json that came from another
-                // source we could handle an error like this.
-                Err(e) => {
-                    eprintln!("serializing json: {}", e);
-
-                    Response::builder()
-                        .status(StatusCode::INTERNAL_SERVER_ERROR)
-                        .body(Body::from("Internal Server Error"))
-                        .unwrap()
-                }
-            };
-
-            Box::new(future::ok(res))
+        (&Method::GET, "/json_api") => {
+            api_get_response()
         }
         _ => {
             // Return 404 not found response.
@@ -122,4 +130,3 @@ fn main() {
         server
     }));
 }
-