Barber handles all your Handlebars precompilation needs. You can use Barber as part of your project build system or with someting like rake-pipeline.

Add this line to your application's Gemfile:

gem 'barber'

And then execute:

$ bundle

Or install it yourself as:

$ gem install barber

You will mainly interact with the utility classes. The utitlity classes delegate to the actual precompiler. They support two primary use cases:

1. Precompiling individual handlebars files.
2. Precompiling inline handlebars templates.

Here are some code examples:

require 'barber'

Barber::FilePrecompiler.call(File.read("template.handlebars"))
# "Handlebars.template(function(...));"

Barber::InlinePreCompiler.call(File.read("template.handlebars"))
# Note the missing semicolon. You can use this with gsub to replace
# calls to inline templates
# "Handlebars.template(function(...))"

Barber also packages Ember precompilers.

require 'barber'

Barber::Ember::FilePrecompiler.call(File.read("template.handlebars"))
# "Ember.Handlebars.template(function(...));"

Barber::Ember::InlinePrecompiler.call(File.read("template.handlebars"))
# "Ember.Handlebars.template(function(...))"

All of Barber's utility classes (demoed above) delegate to Barber::Precompiler. Barber::Precompiler implements a simple public interface you can use to to build your own. A precompiler simply exposes a Barber.precompile JS property. Override Barber::Precompiler#sources to setup your own. Source must respond to #read. Here is an example:

require 'barber'
require 'stringio'

class CustomPrecompiler < Barber::Precompiler
  def sources
    [StringIO.new(custom_compiler)]
  end

  def custom_compiler
    %Q[var Barber = { precompile: function(template) { return "Hello World!" } };]
  end
end

All the utility classes implement call. This means they can be subsituted for procs/lambda where needed. Here's how you can get precompilation of your ember templates with rake-pipeline-web-filters:

require 'barber'

match "**/*.handlebars" do
  handlebars :wrapper_proc => Barber::Ember::FilePrecompiler
end

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Added some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request