First pass at Extractors.

examples/extractors/src/form.rs

@@ -0,0 +1,20 @@
+// <form>
+use actix_web::{web, App, Result};
+use serde::Deserialize;
+
+#[derive(Deserialize)]
+struct FormData {
+    username: String,
+}
+
+/// extract form data using serde
+/// this handler gets called only if the content type is *x-www-form-urlencoded*
+/// and the content of the request could be deserialized to a `FormData` struct
+fn index(form: web::Form<FormData>) -> Result<String> {
+    Ok(format!("Welcome {}!", form.username))
+}
+// </form>
+
+pub fn main() {
+    App::new().route("", web::post().to(index));
+}