structured_menus

An easy way to create flexible menus for Rails apps.

Add this line to your Gemfile and run bundle install:

gem 'structured_menus'

Next, create a configuration file in config/initializers, probably called structured_menus.rb because convention, and add the following to it:

StructuredMenus::Configurator.configure do |config|
  # You don't have to add anything here, if you like the defaults, but you still need to call `configure`.
end

Once you've done the above, create app/menus/menu.yml, and add the following to it:

- name: FAQ
  icon: question
  link: /faq

In the view in which you want to display the menu, add this code:

<%= Rails.menus.show :menu, :dashboard, current_user %>

You can substitute :dashboard for :dropdown if you want a Bootstrap dropdown menu instead; if you don't have a current_user method, use nil.

Continue reading for more detailed usage options.

StructuredMenus enables you to create menus for your app by writing YAML files in (by default) app/menus. Each file is a menu; each item in the file becomes an item on your menu, displayed according to the adapter (more on that later) and options you specify. Such a file might look like this:

- name: Admin
  icon: cogs
  link: /admin
  if: 'lambda { |u| u&.has_role?(:admin) }'

- name: CRM
  icon: users
  link: /crm

- name: Orders
  icon: money-bill-alt
  link: /orders

Save that as mymenu.yml, and you'll be able to call Rails.menus.show :mymenu, :dashboard, current_user to pop it up anywhere in your app.

Adapters are the bits that control how the menu is actually displayed. There are two included by default: :dashboard and :dropdown. Both are designed to work with Bootstrap and FontAwesome (yes, I'm opinionated). Each adapter supports different options - see the definitions in lib/structured_menus/adapters for details on what they are.

• Dashboard is designed to be a full-screen main menu type thing, probably for apps with lots of navigation. The example menu YAML shown above looks like this when shown (some custom CSS - the topbar is not part of the menu):

  

  Use :dashboard in your call to Rails.menus.show to get this adapter.

• Dropdown is, well, a Bootstrap dropdown menu. It doesn't include icons by default, but you can make it do so if you want them. The same YAML looks like this with the dropdown adapter:

  

  Use :dropdown in your call to Rails.menus.show to get this adapter.

If those two don't suit your needs, you can write your own custom adapter. Essentially, this needs to emulate one of the two stock adapters, in that:

• It must respond to #show
• Calls to #show must respond with the string of raw HTML that you want to render.

For reference, here's what the dashboard adapter looks like:

module StructuredMenus::Adapters
  class DashboardAdapter
    include ActionView::Helpers::UrlHelper
    include ActionView::Helpers::OutputSafetyHelper
    
    def self.show(menu, user, **options)
      inst = new
      width = options[:width] || 4
      cards = menu.map do |i|
        next unless !i['if'] || instance_eval(i['if']).call(user)

        cls = options[:class] || 'dashboard-menu-card'
        inst.raw("<div class=\"#{cls}\">#{inst.link_to inst.raw("<i class=\"fas fa-#{i['icon']}\"></i> #{i['name']}"), i['link']}</div>")
      end.compact

      inst.raw(cards.in_groups_of(12 / width).map(&:compact).map do |g|
        '<div class="row">' + g.map { |c| "<div class=\"col-md-#{12 / width}\">#{c}</div>" }.join("\n") + '</div>'
      end.join("\n"))
    end
  end
end

The parameters that will be passed to #show are as follows:

• menu - a parsed YAML file, in the form of an array. Each element is a hash representing a single menu item as specified in the file.
• user is the value passed to Rails.menus.show, which should be a reference to the current user. This can be nil.
• **options is a hash of additional options - it's up to you what you want to support. Look at the adapter files in lib/structured_menus/adapters to see the options that the stock adapters support.

Once you've written your adapter, tell structured_menus about it by adding it to the configuration file:

StructuredMenus::Configurator.configure do |config|
  config.adapters << YourCustomAdapterClass
end

Welcome. Ping me a PR. For large changes you should probably open an issue first to discuss.

Available under the terms of the MIT license.