handlebars-rust
Rust templating with Handlebars templating language.
Getting Started
If you are not familiar with handlebars language syntax, it is recommended to walk through their introduction first.
Check render
example in the source tree. The example shows you how
to:
- Create a
Handlebars
registry and register the template from files; - Create a custom Helper with closure or struct implementing
HelperDef
, and register it; - Define and prepare some data;
- Render it;
Run cargo run --example render
to see results.
(or RUST_LOG=handlebars=info cargo run --example render
for logging
output).
Checkout examples/
for more concrete demos of current API.
From 0.13, you can use either rustc_serialize
or serde
for your
data type. By default we use ToJson
from rustc_serialize
to
convert your data into handlebars internal types. If you use serde
framework in your project, you can enable serde_type
feature of this
crate and we will use Serialize
from serde
to convert.
Documents
Changelog
Change log is available in the source tree named as CHANGELOG.md
.
Why (this) Handlebars?
Handlebars is a real-world templating system that you can use to build your application without pain.
Features
Isolation of Rust and HTML
This library doesn't attempt to use some macro magic to allow you to write your template within your rust code. I admit that it's fun to do that but it doesn't fit real-world use case.
Limited but essential control structure built-in
Only essential control directive if
and each
were built-in. This
prevents you to put too much application logic into your template.
Extensible helper system
You can write your own helper with Rust! It can be a block helper or inline helper. Put you logic into the helper and don't repeat yourself.
A helper can be as a simple as a Rust function like:
/// register the helper
handlebars.register_helper;
And using it in your template:
{{hex my_value}}
Template inheritance
Every time I look into a templating system, I will investigate its support for template inheritance.
Template include is not sufficient for template reuse. In most case you will need a skeleton of page as parent (header, footer, etc.), and embed you page into this parent.
You can find a real example for template inheritance in
examples/partials.rs
, and templates used by this file.
From 0.23 we support Handlebars 4.0 partial syntax by
default. Original partial syntax via block
, partial
helpers are
still supported via feature flag partial_legacy
. Examples can be
find in examples/partials.rs
.
WebAssembly compatible
You can use this handlebars implementation in your rust project that compiles to WebAssembly. Checkout my fork of todomvc demo.
Limitations
- This implementation is not fully compatible with the original
javascript version. Specifically, mustache list iteration and null
check doesn't work. But you can use
#each
and#if
for same behavior. - You will need to make your data
ToJson
-able, so we can render it. If you were on nightly channel, we have a syntax extension to generate defaultToJson
implementation for you. If you use serde, you can enableserde_type
feature of handlebars-rust and add#derive[Serialize]
for your types.
Handlebars-js features supported in Handlebars-rust
- Expression / Block Helpers
- Built-in helpers
- each
- if
- with
- lookup
- log
- Custom helper
- Parameter and hashes for helper, block params
- Partials, include, template inheritance
- Omitting whitespace with
~
- Subexpression
{{(foo bar)}}
- Json expression
a.b.[0]
anda.b.[c]
- RawHelper syntax
{{{{raw-helper}}}}...{{{{/raw-helper}}}}
- Decorator, implemented in Rust way
JavaScript implementation features we don't have
- Mustache block (use
if
/each
instead) - Chained else
Feel free to report an issue if you find something broken. We aren't going to implement all features of handlebars-js, but we should have a workaround for cases we don't support.
Handlebars for Web Frameworks
- Iron: handlebars-iron
- Rocket: rocket/contrib
Using handlebars-rust?
Add your project to our adopters.
License
This library (handlebars-rust) is open sourced under MIT License.