teuffel/loaf

Manages and displays breadcrumb trails in Rails app - lean & mean.

# Loaf [][gem] [][travis] [][codeclimate] [][gemnasium] [][coveralls] [][inchpages]

Loaf manages and displays breadcrumb trails in your Rails application.

Features

• Uses controllers or views to specify breadcrumb trails
• Specify urls using Rails conventions
• No markup assumptions for breadcrumbs rendering
• Use locales file for breadcrumb names
• Tested with Rails >= 3.2 and Ruby >= 2.0.0

Installation

Add this line to your application's Gemfile:

gem 'loaf'

And then execute:

$ bundle

Or install it yourself as:

gem install loaf

Then run the generator:

rails generate loaf:install

1. Usage

Loaf allows you to add breadcrumbs in controllers and views.

In order to add breadcrumbs in controller use breadcrumb method (see 1.1). Outside of controller actions the breadcrumb helper behaviour is similar to filters and as such you can limit breadcrumb scope with familiar options :only, :except. Any breadcrumb specified inside actions creates another level in breadcrumbs trail.

class Blog::CategoriesController < ApplicationController

  breadcrumb 'Article Categories', :blog_categories_path, only: [:show]

  def show
    breadcrumb @category.title, blog_category_path(@category)
  end
end

Loaf adds breadcrumb helper also to the views. Together with controller breadcrumbs, the view breadcrumbs are appended as the last in breadcrumb trail. For instance, to specify view breadcrumb do:

<% breadcrumb @category.title, blog_category_path(@category) %>

Finally, in your view layout add semantic markup to show breadcrumbs:

<ul class='breadcrumbs'>
  <% breadcrumbs do |name, url, styles| %>
    <li class="<%= styles %>">
      <%= link_to name, url %>
      <span><%= styles == 'selected' ? '' : '::' %></span>
    </li>
  <% end %>
</ul>

Usually best practice is to put such snippet inside its own partial.

1.1 breadcrumb

Creation of breadcrumb in Rails is achieved by the breadcrumb helper.

The breadcrumb method takes at minimum two arguments: the first is a name for the crumb that will be displayed and the second is a url that the name points to. The url parameter uses the familiar Rails conventions.

When using path variable blog_categories_path:

breadcrumb 'Categories', blog_categories_path

When using an instance @category:

breadcrumb @category.title, blog_category_path(@category)

You can also use set of objects:

breadcrumb @category.title, [:blog, @category]

You can specify segments of the url:

breadcrumb @category.title, {controller: 'categories', action: 'show', id: @category.id}

1.1.1 breadcrumb in controller

Breadcrumbs are inherited, so if you set a breadcrumb in ApplicationController, it will be inserted as a first element inside every breadcrumb trail. It is customary to set root breadcrumb like so:

class ApplicationController < ActionController::Base
  breadcrumb 'Home', :root_path
end

In controller outside of any action the breadcrumb acts as filter.

class ArticlesController < ApplicationController
  breadcrumb 'All Articles', :articles_path, only: [:new, :create]
end

Loaf allows you to call controller instance methods inside the breadcrumb helper outside of any action. This is useful if your breadcrumb has parameterized behaviour. For example, to dynamically evaluate parameters for breadcrumb title do:

class CommentsController < ApplicationController
  breadcrumb ->(c) { c.find_article(c.params[:post_id]).title }, :articles_path
end

Also, to dynamically evalute parameters inside the url argument do:

class CommentsController < ApplicationController
  breadcrumb 'All Comments', ->(c) { c.post_comments_path(c.params[:post_id]) }
end

1.2 force

Loaf allows you to force a breadcrumb to be current.

For example, on the create action as you are likely want the breadcrumb to be similar as for new action.

class PostsController < ApplicationController
  def create
    breadcrumb 'New Post', new_post_path, force: true
    render action: :new
  end
end

2. Configuration

There is a small set of custom opinionated defaults. The following options are valid parameters:

:crumb_length  # breadcrumb length in integer, default length is 30 characters
:root          # boolean, default is true, displays the home crumb
:capitalize    # set breadcrumbs to have initial letter uppercase, default false
:style_classes # CSS class to be used to style current breadcrumb,
               # defaults to 'selected'

You can override them in your views by passing them to the view breadcrumb helper

<% breadcrumbs crumb_length: 20 do |name, url, styles| %>
  ..
<% end %>

or by adding initializer in config/initializers/loaf.rb:

Loaf.configure do |config|
  config.crumb_length = 20
end

3. Translation

You can use locales files for breadcrumbs' titles. Loaf assumes that all breadcrumb names are scoped inside breadcrumbs namespace inside loaf scope. However, this can be easily changed by passing scope: 'new_scope_name' configuration option.

en:
  loaf:
    breadcrumbs:
      name: 'my-breadcrumb-name'

Therefore, in your controller/view you would do:

class Blog::CategoriesController < ApplicationController
  breadcrumb 'blog.categories', :blog_categories_path
end

And corresponding entry in locale would be:

en:
  loaf:
    breadcrumbs:
      blog:
        categories: 'Article Categories'

Contributing

Questions or problems? Please post them on the issue tracker. You can contribute changes by forking the project and submitting a pull request. You can ensure the tests are passing by running bundle and rake.

Copyright

Copyright (c) 2011-2016 Piotr Murach. See LICENSE.txt for further details.