add --watch-only flag

src/cli.rs

@@ -62,6 +62,10 @@ pub fn build_cli() -> App<'static, 'static> {
                         .default_value("127.0.0.1")
                         .takes_value(true)
                         .help("Changes the base_url"),
+                    Arg::with_name("watch_only")
+                        .long("watch-only")
+                        .takes_value(false)
+                        .help("Do not start a server, just re-build project on changes")
                 ]),
         ])
 }

src/cmd/serve.rs

@@ -166,6 +166,7 @@ pub fn serve(
     output_dir: &str,
     base_url: &str,
     config_file: &str,
+    watch_only: bool,
 ) -> Result<()> {
     let start = Instant::now();
     let (mut site, address) = create_new_site(interface, port, output_dir, base_url, config_file)?;
@@ -206,6 +207,8 @@ pub fn serve(
     // output path is going to need to be moved later on, so clone it for the
     // http closure to avoid contention.
     let static_root = output_path.clone();
+    let broadcaster = if !watch_only {
+
         thread::spawn(move || {
             let s = server::new(move || {
                 App::new()
@@ -226,7 +229,6 @@ pub fn serve(
             println!("Web server is available at http://{}", &address);
             s.run();
         });
-
         // The websocket for livereload
         let ws_server = WebSocket::new(|output: Sender| {
             move |msg: Message| {
@@ -249,6 +251,12 @@ pub fn serve(
         thread::spawn(move || {
             ws_server.listen(&*ws_address).unwrap();
         });
+        Some(broadcaster)
+    } else {
+        println!("Watching in watch only mode, no web server will be started");
+        None
+    };
+
 
     let pwd = env::current_dir().unwrap();
 
@@ -297,43 +305,51 @@ pub fn serve(
                         match detect_change_kind(&pwd, &path) {
                             (ChangeKind::Content, _) => {
                                 console::info(&format!("-> Content changed {}", path.display()));
+                                if let Some(ref broadcaster) = broadcaster {
                                     // Force refresh
                                     rebuild_done_handling(
-                                    &broadcaster,
+                                        broadcaster,
                                         rebuild::after_content_change(&mut site, &path),
                                         "/x.js",
                                     );
                                 }
+                            }
                             (ChangeKind::Templates, _) => {
                                 console::info(&format!("-> Template changed {}", path.display()));
+                                if let Some(ref broadcaster) = broadcaster {
                                     // Force refresh
                                     rebuild_done_handling(
-                                    &broadcaster,
+                                        broadcaster,
                                         rebuild::after_template_change(&mut site, &path),
                                         "/x.js",
                                     );
                                 }
+                            }
                             (ChangeKind::StaticFiles, p) => {
                                 if path.is_file() {
                                     console::info(&format!(
                                         "-> Static file changes detected {}",
                                         path.display()
                                     ));
+                                    if let Some(ref broadcaster) = broadcaster {
                                         rebuild_done_handling(
-                                        &broadcaster,
+                                            broadcaster,
                                             copy_file(&path, &site.output_path, &site.static_path),
                                             &p.to_string_lossy(),
                                         );
                                     }
                                 }
+                            }
                             (ChangeKind::Sass, p) => {
                                 console::info(&format!("-> Sass file changed {}", path.display()));
+                                if let Some(ref broadcaster) = broadcaster {
                                     rebuild_done_handling(
                                         &broadcaster,
                                         site.compile_sass(&site.base_path),
                                         &p.to_string_lossy(),
                                     );
                                 }
+                            }
                             (ChangeKind::Config, _) => {
                                 console::info("-> Config changed. The whole site will be reloaded. The browser needs to be refreshed to make the changes visible.");
                                 site = create_new_site(

src/main.rs

@@ -77,11 +77,12 @@ fn main() {
                     ::std::process::exit(1);
                 }
             }
-
+            let watch_only = matches.is_present("watch_only");
             let output_dir = matches.value_of("output_dir").unwrap();
             let base_url = matches.value_of("base_url").unwrap();
+            println!("watch_only: {}", watch_only);
             console::info("Building site...");
-            match cmd::serve(interface, port, output_dir, base_url, config_file) {
+            match cmd::serve(interface, port, output_dir, base_url, config_file, watch_only) {
                 Ok(()) => (),
                 Err(e) => {
                     console::unravel_errors("", &e);