README.md

handlebars-iron

Handlebars middleware for the Iron web framework.

This library, together with handlebars, iron and hyper, works on both stable and nightly rust.

Both iron and handlebars has backward-incompatible change during 0.x releases. So you will need to choose handlebars-iron version based on those two versions you were using:

handlebars-iron	handlebars	iron
0.14.x	0.16.x	0.2.x
0.15.x	0.18.x	0.3.x
0.16.0	0.19.x	0.3.x
0.17.x	0.19.x	0.4.x
0.18.x	0.20.x (serde 0.8)	0.4.x
0.19.x	0.22.x	0.4.x
0.20.x	0.23.x	0.4.x
0.21.x	0.24.x	0.4.x
0.22.x	0.24.x	0.5.x
0.23.x	0.25.x (serde 0.9)	0.5.x
0.24.x	0.26.x (serde 1.0)	0.5.x
0.25.x	0.29.x	0.5.x
0.26.x	0.32.x	0.6.x
0.27.x	1.x	0.6.x
0.28.x	2.x	0.6.x
0.29.x	3.x	0.6.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);
  }

  chain.link_after(hbse);

If you want register your own custom helpers, you can initialize the HandlebarsEngine from a custom Handlebars registry.

  let mut hbse = HandlebarsEngine::new();
  hbse.add(Box::new(DirectorySource::new("./examples/templates/", ".hbs")));
  hbse.handlebars_mut().register_helper("helper", my_helper);

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

  chain.link_after(hbse);

You can find more information about custom helper in handlebars-rust document.

In your handler, set Template to response. As required by Handlebars-rust, your data should impl serde::Serialize.

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.

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License

MIT, of course.