With Mountain View you create reusable components for your Rails frontend, while generating a living style guide.

FAQ

Hey! What is a living style guide? A living style guide is a style guide that is always up-to-date and never falls behind.

Does it generate it automatically? You bet!

Visit the living style guide demo! (source repo)

Usage of components demo here!

Add this line to your application's Gemfile:

gem 'mountain_view'

Then execute:

$ bundle

Mountain View supports Ruby 2.2+ and Rails 4.2+ (although it may work in older versions)

Use the built-in generator to create a new component:

rails generate mountain_view:component header

This will create the following directory structure:

app/
  components/
    header/
      _header.html.erb
      header.css
      header.js
      header.yml
      header_component.rb # optional

Keep in mind that you can also use scss, coffeescript, haml, or any other preprocessors that your app is currently using.

You can write your own templates on erb, haml or any other templating language. Same goes with stylesheets and javascripts. You can use scss, sass or coffee-script as long as you have these preprocessors running on your app.

<!-- app/components/header/_header.html.erb -->
<div class="header">
  <h1>This is a header component with the title: <%= title %></h1>
  <h3>And subtitle <%= subtitle %></h3>
  <% if show_links? %>
    <ul>
      <% links.each do |link| %>
        <li><%= link %></li>
      <% end %>
    </ul>
  <% end %>
</div>

# app/components/header/header_component.rb
class HeaderComponent < MountainView::Presenter
  properties :title, :subtitle
  property :links, default: []

  def title
    properties[:title].titleize
  end

  def show_links?
    links.any?
  end
end

Including a component class is optional, but it helps avoid polluting your views and helpers with presenter logic. Public methods in your component class will be made available to the view, along with any properties you define. You can also access all properties using the properties method in your component class and views. You can even define property defaults.

You can then call your components on any view by using the following helper:

<%= render_component "header", title: "This is a title", subtitle: "And this is a subtitle" %>

You can also pass a block to a component, for example the following component:

<!-- app/components/header/_header.html.erb -->
<div class="header">
  <%= properties[:yield] %>
</div>

Used in a view like so:

<%= render_component "header" do %>
  <p>Hello World</p>
<% end %>

Would output the following in your view:

<div class="header">
  <p>Hello World</p>
</div>

You can require all the components CSS and JS automatically by requiring mountain_view in your main JS and CSS files.

In case you want to add global stylesheets (e.g. reset, bootstrap, a grid system, etc) to your Mountain View components you can do it by calling them with an initializer

#config/initializers/mountain_view.rb

MountainView.configure do |config|
  config.included_stylesheets = ["reset", "bootstrap"]
end

//= require mountain_view

You don't need to require those again in your application if you're requiring mountain_view already, that will cause duplicate CSS.

For SASS mixins, variables, functions, etc (anything that doesn't generate code), you'd need to explicitly do and @import in each component stylesheet. As that doesn't generate extra CSS this won't cause any issues with the generated CSS, you're only giving that stylesheet access to those definitions.

In case you want to add additional pages to the styleguide (e.g grid, code_style) to your living style guide, you can do it by generating them in an initializer

MountainView.configure do |config|
  config.extra_pages = [:grid, :code_style]
end

This will generate the routes and conventional links to the style guide.

To add the views to handle the request.

rails generate mountain_view:extra_pages

A style guide will be automatically generated. This style guide never falls behind and it reflects your components in their latest version.

1. Add the following line to your routes.rb file. /mountain_view can be any path you want.

mount MountainView::Engine => "/mountain_view", as: "mv_style_guide"

Note: Adding as: :mv_style_guide is needed to establish a consistent name for the style guide to provide a link to the main page.

2. Create stubs for your components. These stubs will be the examples in the style guide.

E.g: app/components/card/card.yml

    -
      :title: "Aspen Snowmass"
      :description: "Aspen Snowmass is a winter resort complex located in Pitkin County in western Colorado in the United States. Owned and operated by the Aspen Skiing Company it comprises four skiing/snowboarding areas on four adjacent mountains in the vicinity of the towns of Aspen and Snowmass Village."
      :link: "http://google.com"
      :image_url: "http://i.imgur.com/QzuIJTo.jpg"
      :data:
      -
        :title: "Elevation"
        :number: '7879ft'
      -
        :title: "Depth"
        :number: '71"'
    -
      :title: "Sunset on the Mountain"
      :description: "Three major ranges of the Alps – the Northern Calcareous Alps, Central Alps, and Southern Calcareous Alps – run west to east through Austria. The Central Alps, which consist largely of a granite base, are the largest and highest ranges in Austria."
      :link: "http://google.com"

3. Visit http://localhost:3000/mountain_view/styleguide

Visit the living style guide demo! (source repo)

Usage of components demo here!

To override the path used within the mountain_view engine, set the styleguide_path option.

#config/initializers/mountain_view.rb

MountainView.configure do |config|
  config.styleguide_path = "my-style-guide"
end

To customize the styleguide, override the style guide layout by adding mountain_view.html.erb (or mountain_view.html.haml if using haml) to your application layouts folder in views.

You can customize the title, description for each example in the stub, as well as the classes that surround the stub example. In order to override the default title, add a title key to the mv_stub_meta hash. Additional special keys include description which will add a description under the title for a given example and classes which will add classes for a specific example.

E.g: app/components/card/card.yml

    -
      :mv_stub_meta:
        :title: "Specific Example"
        :description: "Instructions for use case or other UX considerations"
        :classes: "black-background"
      :title: "Aspen Snowmass"
      :description: "Aspen Snowmass is a winter resort complex located in Pitkin County in western Colorado in the United States. Owned and operated by the Aspen Skiing Company it comprises four skiing/snowboarding areas on four adjacent mountains in the vicinity of the towns of Aspen and Snowmass Village."
      :link: "http://google.com"
      :image_url: "http://i.imgur.com/QzuIJTo.jpg"
      :data:
      -
        :title: "Elevation"
        :number: '7879ft'
      -
        :title: "Depth"
        :number: '71"'

Rendering a large amount of partials in a request can lead to a performance bottleneck, usually this is caused by the parsing and rendering of template code such as ERB or HAML.

Via a Mountain View component you can render your HTML without touching a template parsing engine, which is super performant! To do this, you'll need to override render(context, &block) method, which is inherited from MountainView::Presenter class.

For example, if you had a component called blank_state with the Erb of:

<!-- app/components/blank_state/_blank_state.html.erb -->
<div class="blank-state <%= properties[:class] %>"></div>

You'd override the render method in blank_state_component.rb like so:

# app/components/blank_state/blank_state_component.rb
class BlankStateComponent < MountainView::Presenter
  properties :class

  # Override the inherited render method to not read partials from the file system.
  def render(context, &block)
    # context is the view we've being rendered from, so it has all Rails helpers
    context.content_tag(:div, '', class: [
      'blank-state',
      properties[:class]
    ].compact.join(' '))
  end
end

Anecdotally, a request which had to render 50 partials and took a whopping 2000ms was reduced to 200ms using this technique.

See the contributing guide.

• Esteban Pastorino
• Ignacio Gutierrez

This library was inspired by Rizzo, a wonderful living style guide created by the guys at LonelyPlanet. More info here