Veil

Mustache templates for both Ruby & JavaScript.

Alpha, not even beta

Veil is in early alpha stage. In fact, as of this writing, there isn't even a line of code written. Don't expect production-ready-anything anytime soon.

Usage:

IMPORTANT: The following steps don't work yet - this is merely "README-driven-development" at this point.

Setup:

$: echo "gem 'veil'" > Gemfile
$: bundle install

Basic Mustache-template Usage:

Veil can be used solely to serve up mustache templates if you so desire. Just write your templates under /app/templates like so:

# /app/templates/todo.jst.erb
<li>{{name}}</li>

As a decorator:

Veil uses the most excellent Draper gem under the covers, so anything you can do with Draper, you can do with a Veil template. To generate a Veil template that decorates a model called Todo:

rails generate veil:decorator Todo

This generates a decorator at /app/decorators/todo_decorator.rb that can be used just like any Draper decorator. It also generates a corresponding template at /app/templates/todo.jst.erb

Any method calls within the template will use your decorator when called from Ruby, and will render JavaScript-ready handlebars when compiled to application.js:

# /app/decorators/todo.rb
class TodoDecorator < ApplicationDecorator
  use Veil::Base

  def due_date
    date = h.content_tag(:span, todo.due_at.strftime("%A, %B %e").squeeze(" "), :class => 'date')
    time = h.content_tag(:span, todo.due_at.strftime("%l:%M%p"), :class => 'time').delete(" ")
    h.content_tag :span, date + time, :class => 'due_date'
  end
end

# /app/controllers/todos_controller.rb
class TodosController < ApplicationController

  def show
    @todo = TodoDecorator.find(params[:id])
  end

end

# /app/views/todos/show.html.erb
<p>Todo: <%= @todo.title %> (Due: <%= @todo.due_date %>)</p>

So, assuming your routes are all set up as usual, when you visit /todos/1 you should get:

<p>Todo: Shave a yak (Due: <span class="due_date"><span class="date">Wednesday,
February 1</span><span class="time"> 4:41PM</span></span>)</p>

And when you visit /assets/application.js you should get the following template (by default saved in an object called Handlebars.templates with key todo_template):

<p>Todo: {{title}} (Due: {{dueDate}})</p>

TODO / Roadmap:

1. Figure out ways to preserve some decorator behavior from Draper when carrying over to JS Templates. eg: t'would be nice to somehow get <span class="date"> etc involved.

Asset Dependencies:

TODO: Figure out the idiomatic way to deal w/ template & specific decorator changes in deve mode

Goals

Veil is intended to allow Rails developers to maximize the usefulness of their JavaScript templates, and minimize duplication. To achieve this, some up-front design decisions:

1. I should be able to use a templating language of my choice (so, anything Tilt can handle - slim, haml, erb, etc).
2. Veil templates should be useful both server-side and client-side (using decorators server-side, and rendering "handlebars" client-side)
3. Veil templates shouldn't lock you into using Veil - we'll rely on well-established precedent and name our files in a way that they can be used later if you choose to stop using Veil. eg: /app/templates/todo.jst.slim
4. My views should not need to reference templates or be concerned about which templates they will need. We'll follow the lead of the Hamlbars gem and render all templates (by default) to application.js when the asset pipeline does its thing - they will already be loaded into a configurable client-side variable without needing to call render partial: 'templates/todo'.