Haml for JavaScript templates with the asset pipeline

Writing JavaScript templates for Backbone.js (or other frameworks) in your app? Would you like to use haml in the asset pipeline?

This gem adds haml support to the Rails 3.1+ asset pipeline. You will also need a gem that creates a compiled JavaScript template like hogan_assets or handlebars_assets as well.


Add this to your Gemfile

gem 'haml_assets'

Upgrading from 0.0.x

haml_assets now works with the haml gem. Please update your gemfile to only require haml_assets..

Writing your JavaScript templates

Templates directory

You should located your templates under app/assets; we suggest app/assets/templates. In your JavaScript manifest file (for example application.js), use require_tree

//= require_tree ../templates

The template file

Inside your templates directory, add your template file. The file should be named as follows


The asset pipeline will then generate the actual JavaScript asset

  1. Convert your haml to HTML
  2. Compile the HTML to an mustache Javascript template using hogan_assets

Important! The asset pipeline is not invoking a controller to generate the templates. If you are using existing view templates, you may have to edit templates to remove some references to controller helpers.


All the ActionView and route helpers are available in your template. If you use form_for and the related helpers, you should use the new object style, even if you are writing an edit template, for example

= form_for :contact, url: "javascript_not_working", html: {:class => :edit_contact, :method => :put} do |f|
  = f.label :name, "Name"
  = f.text_field :name, class: 'text required', autofocus: true, value: '{{name}}'

Rendering partials

You can render partials within your views. Because this is hacked in, you can nest your partials as normal, but they must have a recognized format such as html. For example


A partial will become a part of whatever template you are rendering, so make sure that you are generating the correct markup. For example, do not include an embedded coffeescript partial inside an embedded javascript template.

Finding partials in app/views

Warning this is a potentially confusing option!

If you need to share a partial with Rails views, you can tell haml_assets to share partials with the Rails app by looking for the templates in app/views. Add this to an initializer:

HamlAssets::Config.look_in_app_views = true

Now your asset pipeline haml views will additionally look for partials in the usual Rails location app/views.

See this issue from handlebars_assets for a dicussion of the asset pipeline and initializers issue 34.


Once you've made your great commits:

  1. Fork
  2. Create a topic branch - git checkout -b my_branch
  3. Push to your branch - git push origin my_branch
  4. Create a Pull Request from your branch
  5. That's it!


  • Les Hill : @leshill
  • Wes Gibbs : @wgibbs


  • Eugene Pimenov (@libc) : Rendering partials
  • Raphael Randschau (@nicolai86) : Render partials