middleware example

middleware/src/simple.rs

@@ -1,13 +1,29 @@
 extern crate actix_web;
 
-use actix_web::middleware::{Middleware, Started};
-use actix_web::{HttpRequest, Result};
+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");
+    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
+    }
 }