finish web server version of gcd example

iron-gcd/Cargo.toml

@@ -5,7 +5,9 @@ authors = ["Timothy Warren <tim@timshomepage.net>"]
 edition = "2018"
 
 [dependencies]
+gcd = { path = "../gcd", version = "0.1.0" }
 iron = "0.5.1"
 mime = "0.2.3"
 router = "0.5.1"
 urlencoded = "0.5.0"
+

iron-gcd/src/main.rs

@@ -1,15 +1,24 @@
+extern crate gcd;
 extern crate iron;
 extern crate router;
+extern crate urlencoded;
 #[macro_use] extern crate mime;
 
+use gcd::gcd;
 use iron::prelude::*;
 use iron::status;
 use router::Router;
+use std::str::FromStr;
+use urlencoded::UrlEncodedBody;
 
 fn main() {
+    let mut router = Router::new();
+    router.get("/", get_form, "root");
+    router.post("/gcd", post_gcd, "gcd");
+
     println!("Serving on http://localhost:3000...");
 
-    Iron::new(get_form).http("localhost:3000").unwrap();
+    Iron::new(router).http("localhost:3000").unwrap();
 }
 
 fn get_form(_request: &mut Request) -> IronResult<Response> {
@@ -21,10 +30,60 @@ fn get_form(_request: &mut Request) -> IronResult<Response> {
         <title>GCD Calculator</title>
         <form action="/gcd" method="post">
             <input type="number" min="0" name="n" />
-            <input type="number" min="0" name="m" />
+            <input type="number" min="0" name="n" />
             <button type="submit">Compute GCD</button>
         </form>
     "#);
 
     Ok(response)
 }
+
+fn post_gcd(request: &mut Request) -> IronResult<Response> {
+    let mut response = Response::new();
+
+    let form_data = match request.get_ref::<UrlEncodedBody>() {
+        Err(e) => {
+            response.set_mut(status::BadRequest);
+            response.set_mut(format!("Error parsing form data: {:?}\n", e));
+            return Ok(response)
+        },
+        Ok(map) => map,
+    };
+
+    let unparsed_numbers = match form_data.get("n") {
+        None => {
+            response.set_mut(status::BadRequest);
+            response.set_mut(format!("form data has no 'n' parameter\n"));
+            return Ok(response);
+        },
+        Some(nums) => nums,
+    };
+
+    let mut numbers = Vec::new();
+
+    for unparsed in unparsed_numbers {
+        match u64::from_str(&unparsed) {
+            Err(_) => {
+                response.set_mut(status::BadRequest);
+                response.set_mut(format!("Value for 'n' parameter not a number: {:?}\n", unparsed));
+                return Ok(response);
+            },
+            Ok(n) => {
+                numbers.push(n);
+            },
+        }
+    }
+
+    let mut d = numbers[0];
+    for m in &numbers[1..] {
+        d = gcd(d, *m);
+    }
+
+    response.set_mut(status::Ok);
+    response.set_mut(mime!(Text/Html; Charset=Utf8));
+    response.set_mut(
+        format!("The greatest common divisor of the numbers {:?} is <B>{}</b>\n", numbers, d)
+    );
+
+    Ok(response)
+}