docs: add guarded-listings example

actix-files/examples/guarded-listing.rs

@@ -0,0 +1,33 @@
+use actix_files::Files;
+use actix_web::{get, guard, middleware, App, HttpServer, Responder};
+
+const EXAMPLES_DIR: &str = concat![env!("CARGO_MANIFEST_DIR"), "/examples"];
+
+#[get("/")]
+async fn index() -> impl Responder {
+    "Hello world!"
+}
+
+#[actix_web::main]
+async fn main() -> std::io::Result<()> {
+    env_logger::init_from_env(env_logger::Env::new().default_filter_or("info"));
+
+    log::info!("starting HTTP server at http://localhost:8080");
+
+    HttpServer::new(|| {
+        App::new()
+            .service(index)
+            .service(
+                Files::new("/assets", EXAMPLES_DIR)
+                    .show_files_listing()
+                    .guard(guard::Header("show-listing", "?1")),
+            )
+            .service(Files::new("/assets", EXAMPLES_DIR))
+            .wrap(middleware::Compress::default())
+            .wrap(middleware::Logger::default())
+    })
+    .bind(("127.0.0.1", 8080))?
+    .workers(2)
+    .run()
+    .await
+}