Gretel is a Ruby on Rails plugin that makes it easy yet flexible to create breadcrumbs.

Installation

In your Gemfile:

gem 'gretel', '2.0.0.beta1'

And run:

$ bundle install

Example

Start by generating an initializer:

$ rails generate gretel:install

Then, in config/initializers/breadcrumbs.rb:

Gretel::Crumbs.layout do
  # Root crumb
  crumb :root do
    link "Home", root_path
  end
  
  # Regular crumb
  crumb :projects do
    link "Projects", projects_path
  end

  # Parent crumbs
  crumb :project_issues do |project|
    link "Issues", project_issues_path(project)
    parent :project, project
  end
  
  # Child 
  crumb :issue do |issue|
    link issue.name, issue_path(issue)
    parent :project_issues, issue.project
  end
  
  # Multiple links per crumb (recursive links for parent categories)
  crumb :category do |category|
    parents = [category]
  
    parent_category = category
    while parent_category = parent_category.parent_category
      parents.unshift parent_category
    end
  
    parents.each do |category|
      link category.name, category
    end

    parent :categories
  end
  
  # Product crumb with recursive parent categories
  crumb :product do |product|
    link product.name, product
    parent :category, product.category
  end

  # Multiple arguments
  crumb :multiple_test do |a, b, c|
    link "Test #{a}, #{b}, #{c}", test_path
    parent :other_test, 3, 4, 5
  end
end

At the top of app/views/issues/show.html.erb, set the current breadcrumb:

<% breadcrumb :issue, @issue %>

Then, in app/views/layouts/application.html.erb:

<%= breadcrumbs :pretext => "You are here: ",
                :separator => " &rsaquo; ",
                :semantic => true %>

This will generate a <div class="breadcrumbs"> containing the breadcrumbs.

Building the breadcrumbs manually

If you supply a block to the breadcrumbs method, it will yield an array with the breadcrumb links so you can build the breadcrumbs HTML manually:

<% breadcrumbs do |links| %>
  <% if links.any? %>
    You are here:
    <% links.each do |link| %>
      <%= link_to link.text, link.url %> (<%= link.key %>)
    <% end %>
  <% end %>
<% end %>

Options

You can pass options to <%= breadcrumbs %>, e.g. <%= breadcrumbs :pretext => "You are here:" %>:

Option	Description	Default
:pretext	Text to be rendered before breadcrumb, e.g. "You are here: "	None
:posttext	Text to be appended after breadcrumb, e.g. "Text after breacrumb"	None
:separator	Separator between links, e.g. " › "	" > "
:autoroot	Whether it should automatically link to the :root crumb if no parent is given.	False
:show_root_alone	Whether it should show :root if that is the only link.	False
:link_current	Whether the current crumb should be linked to.	False
:semantic	Whether it should generate semantic breadcrumbs.	False
:id	ID for the breadcrumbs container.	None
:class	CSS class for the breadcrumbs container.	"breadcrumbs"
:current_class	CSS class for the current link or span.	"current"

Documentation

• Full documentation
• Changelog

Contributors

• See the list of contributors

Copyright (c) 2010-2013 Lasse Bunk, released under the MIT license