From cbb81bc747da20ab98f0338d9ac878391c9089d3 Mon Sep 17 00:00:00 2001
From: Nikolay Kim <fafhrd91@gmail.com>
Date: Wed, 20 Dec 2017 15:12:43 -0800
Subject: [PATCH] json request example

---
 examples/json/Cargo.toml  | 16 ++++++++++
 examples/json/client.py   | 17 +++++++++++
 examples/json/src/main.rs | 64 +++++++++++++++++++++++++++++++++++++++
 guide/src/qs_7.md         | 41 ++++++++++++++++++++++++-
 4 files changed, 137 insertions(+), 1 deletion(-)
 create mode 100644 examples/json/Cargo.toml
 create mode 100644 examples/json/client.py
 create mode 100644 examples/json/src/main.rs

diff --git a/examples/json/Cargo.toml b/examples/json/Cargo.toml
new file mode 100644
index 000000000..468b04900
--- /dev/null
+++ b/examples/json/Cargo.toml
@@ -0,0 +1,16 @@
+[package]
+name = "json-example"
+version = "0.1.0"
+authors = ["Nikolay Kim <fafhrd91@gmail.com>"]
+
+[dependencies]
+bytes = "0.4"
+futures = "0.1"
+env_logger = "*"
+
+serde = "1.0"
+serde_json = "1.0"
+serde_derive = "1.0"
+
+actix = "^0.3.1"
+actix-web = { git = "https://github.com/actix/actix-web.git" }
diff --git a/examples/json/client.py b/examples/json/client.py
new file mode 100644
index 000000000..31429443d
--- /dev/null
+++ b/examples/json/client.py
@@ -0,0 +1,17 @@
+# This script could be used for actix-web multipart example test
+# just start server and run client.py
+
+import json
+import asyncio
+import aiohttp
+
+async def req():
+    resp = await aiohttp.ClientSession().request(
+        "post", 'http://localhost:8080/',
+        data=json.dumps({"name": "Test user", "number": 100}),
+        headers={"content-type": "application/json"})
+    print(str(resp))
+    assert 200 == resp.status
+
+
+asyncio.get_event_loop().run_until_complete(req())
diff --git a/examples/json/src/main.rs b/examples/json/src/main.rs
new file mode 100644
index 000000000..c271c12b0
--- /dev/null
+++ b/examples/json/src/main.rs
@@ -0,0 +1,64 @@
+extern crate actix;
+extern crate actix_web;
+extern crate bytes;
+extern crate futures;
+extern crate env_logger;
+extern crate serde_json;
+#[macro_use] extern crate serde_derive;
+
+use actix_web::*;
+use bytes::BytesMut;
+use futures::Stream;
+use futures::future::{Future, ok, err, result};
+
+#[derive(Debug, Deserialize)]
+struct MyObj {
+    name: String,
+    number: i32,
+}
+
+fn index(mut req: HttpRequest) -> Result<Box<Future<Item=HttpResponse, Error=Error>>> {
+    // check content-type, early error exit
+    if req.content_type() != "application/json" {
+        return Err(error::ErrorBadRequest("wrong content-type").into())
+    }
+
+    Ok(Box::new(
+        // load request body
+        req.payload_mut()
+            .readany()
+            .fold(BytesMut::new(), |mut body, chunk| {
+                body.extend(chunk);
+                result::<_, error::PayloadError>(Ok(body))
+            })
+            .map_err(|e| Error::from(e))
+            .and_then(|body| {
+                // body is loaded, now we can deserialize json
+                match serde_json::from_slice::<MyObj>(&body) {
+                    Ok(obj) => {
+                        println!("MODEL: {:?}", obj);    // <- do something with payload
+                        ok(httpcodes::HTTPOk.response()) // <- send response
+                    },
+                    Err(e) => {
+                        err(error::ErrorBadRequest(e).into())
+                    }
+                }
+            })))
+}
+
+fn main() {
+    ::std::env::set_var("RUST_LOG", "actix_web=info");
+    let _ = env_logger::init();
+    let sys = actix::System::new("json-example");
+
+    HttpServer::new(|| {
+        Application::new()
+            // enable logger
+            .middleware(middlewares::Logger::default())
+            .resource("/", |r| r.method(Method::POST).f(index))})
+        .bind("127.0.0.1:8080").unwrap()
+        .start();
+
+    println!("Started http server: 127.0.0.1:8080");
+    let _ = sys.run();
+}
diff --git a/guide/src/qs_7.md b/guide/src/qs_7.md
index b69e67899..bb1a14367 100644
--- a/guide/src/qs_7.md
+++ b/guide/src/qs_7.md
@@ -55,7 +55,46 @@ fn index(req: HttpRequest) -> HttpResponse {
 }
 # fn main() {}
 ```
- 
+
+
+## JSON Request
+
+Unfortunately, because of async nature of actix web framework, deserializing json
+requests is not very ergonomic process. First you need to load whole body into
+temporal storage and only then you can deserialize it.
+
+Here is simple example. We will deserialize *MyObj* struct.
+
+```rust,ignore
+#[derive(Debug, Deserialize)]
+struct MyObj {
+    name: String,
+    number: i32,
+}
+```
+
+We need to load request body first.
+
+```rust,ignore
+fn index(mut req: HttpRequest) -> Future<Item=HttpResponse, Error=Error> {
+
+   req.payload_mut().readany()
+     .fold(BytesMut::new(), |mut body, chunk| {   // <- load request body
+         body.extend(chunk);
+         result::<_, error::PayloadError>(Ok(body))
+     })
+    .and_then(|body| {  // <- body is loaded, now we can deserialize json
+        let obj = serde_json::from_slice::<MyObj>(&body).unwrap();
+        println!("MODEL: {:?}", obj);    // <- do something with payload
+        ok(httpcodes::HTTPOk.response()) // <- send response
+    })
+}
+```
+
+Full example is available in 
+[examples directory](https://github.com/actix/actix-web/tree/master/examples/json/).
+
+
 ## JSON Response
 
 The `Json` type allows you to respond with well-formed JSON data: simply return a value of