Merge pull request sunng87#11 from sunng87/chore/feature-opt-in

(chore) make watch function an optional feature

Cargo.toml

@@ -18,4 +18,8 @@ handlebars = "*"
 rustc-serialize = "*"
 plugin = "*"
 walker = "*"
-notify = "*"
+notify = { version = "*", optional = true }
+
+[features]
+default = []
+watch = ["notify"]

README.md

@@ -58,14 +58,28 @@ During development you may want to live-reload your templates without
 having to restart your web server. Here comes the live-reload
 feature.
 
+Since live-reload may only be useful in development phase, we have
+made it a optional feature. In order to enable it, you will need to
+add feature `watch` in your cargo declaration:
+
+```
+[features]
+## create a feature in your app
+watch = ["handlebars-iron/watch"]
+
+[dependencies]
+handlebars-iron = "*"
+```
+
 ```rust
     let template_engine_ref = Arc::new(HandlebarsEngine::new("./examples/templates/", ".hbs"));
     template_engine_ref.watch();
 
     chain.link_after(template_engine_ref);
 ```
 
-Check `examples/watch_server.rs` for further information.
+Check `examples/watch_server.rs` for further information. To test it:
+`cargo run --example watch_server --features watch`.
 
 ## License
 

examples/watch_server.rs

@@ -1,10 +1,13 @@
+#![allow(dead_code, unused_imports)]
 extern crate iron;
 extern crate handlebars_iron as hbs;
 extern crate rustc_serialize;
 
 use iron::prelude::*;
 use iron::{status};
-use hbs::{Template, HandlebarsEngine, Watchable};
+use hbs::{Template, HandlebarsEngine};
+#[cfg(feature = "watch")]
+use hbs::Watchable;
 use rustc_serialize::json::{ToJson, Json};
 use std::collections::BTreeMap;
 use std::sync::Arc;
@@ -50,6 +53,7 @@ fn hello_world(_: &mut Request) -> IronResult<Response> {
     Ok(resp)
 }
 
+#[cfg(feature = "watch")]
 fn main() {
     let mut chain = Chain::new(hello_world);
     let template_engine_ref = Arc::new(HandlebarsEngine::new("./examples/templates/", ".hbs"));
@@ -60,3 +64,8 @@ fn main() {
     println!("Server running at http://localhost:3000/");
     Iron::new(chain).http("localhost:3000").unwrap();
 }
+
+#[cfg(not(feature = "watch"))]
+fn main() {
+    println!("Watch only enabled via --features watch option");
+}

src/lib.rs

@@ -19,12 +19,16 @@ extern crate iron;
 extern crate rustc_serialize as serialize;
 extern crate handlebars;
 extern crate plugin;
-extern crate notify;
 extern crate walker;
+#[cfg(feature = "watch")]
+extern crate notify;
+
 
 pub use self::middleware::Template;
 pub use self::middleware::HandlebarsEngine;
+#[cfg(feature = "watch")]
 pub use self::watch::Watchable;
 
 mod middleware;
+#[cfg(feature = "watch")]
 mod watch;