Merge pull request #27 from casperin/middleware-example

Middleware example

.travis.yml

@@ -45,6 +45,7 @@ script:
       cd http-proxy && cargo check && cd ..
       cd json && cargo check && cd ..
       cd juniper && cargo check && cd ..
+      cd middleware && cargo check && cd ..
       cd multipart && cargo check && cd ..
       cd protobuf && cargo check && cd ..
       cd r2d2 && cargo check && cd ..

Cargo.lock

@@ -1038,6 +1038,14 @@ name = "memoffset"
 version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "middleware-example"
+version = "0.1.0"
+dependencies = [
+ "actix 0.5.8 (registry+https://github.com/rust-lang/crates.io-index)",
+ "actix-web 0.6.12 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "mime"
 version = "0.3.7"

Cargo.toml

@@ -12,6 +12,7 @@ members = [
   "http-proxy",
   "json",
   "juniper",
+  "middleware",
   "multipart",
   "protobuf",
   "r2d2",

middleware/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "middleware-example"
+version = "0.1.0"
+authors = ["Gorm Casper <gcasper@gmail.com>"]
+
+[dependencies]
+actix = "0.5"
+actix-web = "^0.6"

middleware/README.md

@@ -0,0 +1,11 @@
+## Middleware example
+
+```bash
+cd form
+cargo run
+# Started http server: 127.0.0.1:8080
+```
+
+Look in `src/main.rs` and comment the different middlewares in/out to see how
+they function.
+

middleware/src/main.rs

@@ -0,0 +1,29 @@
+extern crate actix;
+extern crate actix_web;
+
+use actix_web::{server, App};
+
+#[allow(dead_code)]
+mod redirect;
+#[allow(dead_code)]
+mod simple;
+
+fn main() {
+    let sys = actix::System::new("middleware-example");
+
+    let _addr = server::new(|| {
+        App::new()
+            .middleware(simple::SayHi)
+            // .middleware(redirect::CheckLogin)
+            .resource("/login", |r| {
+                r.f(|_| "You are on /login. Go to src/redirect.rs to change this behavior.")
+            })
+            .resource("/", |r| {
+                r.f(|_| "Hello, middleware! Check the console where the server is run.")
+            })
+    }).bind("127.0.0.1:8080")
+        .unwrap()
+        .start();
+
+    let _ = sys.run();
+}

middleware/src/redirect.rs

@@ -0,0 +1,28 @@
+extern crate actix_web;
+
+use actix_web::middleware::{Middleware, Started};
+use actix_web::{http, HttpRequest, HttpResponse, Result};
+
+pub struct CheckLogin;
+
+impl<S> Middleware<S> for CheckLogin {
+    // We only need to hook into the `start` for this middleware.
+    fn start(&self, req: &mut HttpRequest<S>) -> Result<Started> {
+        let is_logged_in = false; // Change this to see the change in outcome in the browser
+
+        if is_logged_in {
+            return Ok(Started::Done);
+        }
+
+        // Don't forward to /login if we are already on /login
+        if req.path() == "/login" {
+            return Ok(Started::Done);
+        }
+
+        Ok(Started::Response(
+            HttpResponse::Found()
+                .header(http::header::LOCATION, "/login")
+                .finish(),
+        ))
+    }
+}

middleware/src/simple.rs

@@ -0,0 +1,29 @@
+extern crate actix_web;
+
+use actix_web::middleware::{Finished, Middleware, Response, Started};
+use actix_web::{HttpRequest, HttpResponse, Result};
+
+// Middleware can get called at three stages during the request/response handling. Below is a
+// struct that implements all three of them.
+pub struct SayHi;
+
+impl<S> Middleware<S> for SayHi {
+    fn start(&self, req: &mut HttpRequest<S>) -> Result<Started> {
+        println!("Hi from start. You requested: {}", req.path());
+        Ok(Started::Done)
+    }
+
+    fn response(
+        &self,
+        _req: &mut HttpRequest<S>,
+        resp: HttpResponse,
+    ) -> Result<Response> {
+        println!("Hi from response");
+        Ok(Response::Done(resp))
+    }
+
+    fn finish(&self, _req: &mut HttpRequest<S>, _resp: &HttpResponse) -> Finished {
+        println!("Hi from finish");
+        Finished::Done
+    }
+}