handlebars-iron

Handlebars middleware for the Iron web framework.

The most recent version of handlebars-iron, like Hyper, Iron and Handlebars-rust, now compiles on nightly, beta and latest stable (1.7.0+) channel. Our travis task will track the compatibility on all these channels.

Handlebars-iron 0.14.x works with Iron 0.3.x and Hyper 0.8.x. If you were using Iron 0.2.x you can stick with handlebars-iron 0.13.x.

Usage

Add HandlebarsEngine to your Iron middleware chain as an "after" middleware.

  /// HandlebarsEngine will look up all files with "./examples/templates/**/*.hbs"
  let mut hbse = HandlebarsEngine::new();
  hbse.add(Box::new(DirectorySource::new("./examples/templates/", ".hbs")));

  // load templates from all registered sources
  if let Err(r) = hbse.reload() {
    panic!("{}", r.description());
  }

  chain.link_after(hbse);

In your handler, set Template to response. As required by Handlebars-rust, your data should impl serialize::json::ToJson. If you are on nightly channel, it is highly recommended to use tojson_macros to generate default ToJson implementation without repeating yourself.

For DirectorySource, handlebars engine will walk the directory specified by prefix, try to register all templates matches the suffix, and extract its name as template name. For instance, ./examples/templates/some/path/index.hbs will be registered as some/path/index.

/// render data with "index" template
/// that is "./examples/templates/index.hbs"
fn hello_world(_: &mut Request) -> IronResult<Response> {
    let mut resp = Response::new();

    let data = ...
    resp.set_mut(Template::new("index", data)).set_mut(status::Ok);
    Ok(resp)
}

By using Template::with You can also render some template without actually register it. But this is not recommended because template string needs to be parsed every time. Consider using a MemorySource if possible.

/// render data with "index" template
/// that is "./examples/templates/index.hbs"
fn hello_world(_: &mut Request) -> IronResult<Response> {
    let mut resp = Response::new();

    let data = ...
    resp.set_mut(Template::with("<h1>{{title}}</h1>", data)).set_mut(status::Ok);
    Ok(resp)
}

Since this is simple library, you may run this example with RUST_LOG=handlebars_iron=info cargo run --example server first, and documentation then.

Rust and its ecosystem are still in early stage, this project might been broken for various reasons. I will try my best to keep this library compiles with latest Rust nightly before the 1.0 final release. If you find anything bad, pull requests and issue reporting are always welcomed.

Live reload

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 = ...

Check examples/watch_server.rs for further information. To test it: RUST_LOG=handlebars_iron=info cargo run --example watch_server --features watch.

Serde

From 0.11.0, by enabling feature serde_type, you can also use serde_json as type system. Typically you can annotate your type with #[derive(Serialize)] to make it work as template data.

You can find an working example in examples/server.rs and try to run it via: cargo run --features unstable --example server --no-default-features

License

MIT, of course.