Lotus::Helpers

View helpers for Ruby applications

Status

Contact

• Home page: http://lotusrb.org
• Mailing List: http://lotusrb.org/mailing-list
• API Doc: http://rdoc.info/gems/lotus-helpers
• Bugs/Issues: https://github.com/lotus/helpers/issues
• Support: http://stackoverflow.com/questions/tagged/lotus-ruby
• Chat: https://gitter.im/lotus/chat

Rubies

Lotus::Helpers supports Ruby (MRI) 2+

Installation

Add this line to your application's Gemfile:

gem 'lotus-helpers'

And then execute:

$ bundle

Or install it yourself as:

$ gem install lotus-helpers

Usage

Lotus::Helpers offers a set of utilities to enrich web views.

HTML helper

HTML5 markup generator (#html).

View:

module Users
  class Show
    include Lotus::Helpers

    def sidebar
      html.aside(id: 'sidebar') do
        p "Languages", class: 'title'

        ul do
          li "Italian"
          li "English"
        end
      end
    end
  end
end

Template:

<%= sidebar %>

Output:

<aside id="sidebar">
  <p class="title">Languages</p>

  <ul>
    <li>Italian</li>
    <li>English</li>
  </ul>
</aside>

Form Helper

Form generator for HTML5 (#form_for)

Template Usage

Template:

<%=
  form_for :book, routes.books_path do
    text_field :title

    submit 'Create'
  end
%>

Output:

<form action="/books" method="POST" accept-charset="utf-8" id="book-form">
  <input type="text" name="book[title]" id="book-id" value="">
  <button type="submit">Create</button>
</form>

View Usage

View:

module Books
  class New
    include Lotus::Helpers

    def form
      form_for :book, routes.books_path do
        text_field :title

        submit 'Create'
      end
    end
  end
end

Template:

<%= form %>

Output:

<form action="/books" method="POST" accept-charset="utf-8" id="book-form">
  <input type="text" name="book[title]" id="book-id" value="">
  <button type="submit">Create</button>
</form>

Reuse Code

Views:

module Books
  class New
    include Lotus::Helpers

    def form
      Form.new(:book, routes.books_path)
    end

    def submit_label
      'Create'
    end
  end

  class Edit
    include Lotus::Helpers

    def form
      Form.new(:book, routes.book_path(id: book.id), {book: book}, {method: :patch})
    end

    def submit_label
      'Update'
    end
  end
end

Templates:

# books/new.html.erb
<%= render partial: 'books/form' %>

# books/edit.html.erb
<%= render partial: 'books/form' %>

# books/_form.html.erb
<%=
  form_for form, class: 'form-horizontal' do
    text_field :title

    submit submit_label
  end
%>

Output for new:

<form action="/books" method="POST" accept-charset="utf-8" id="book-form">
  <input type="text" name="book[title]" id="book-id" value="">
  <button type="submit">Create</button>
</form>

Output for edit:

<form action="/books/23" method="POST" accept-charset="utf-8" id="book-form">
  <input type="hidden" name="_method" value="PATCH">
  <input type="text" name="book[title]" id="book-id" value="TDD">
  <button type="submit">Update</button>
</form>

Escape helper

HTML (#h), HTML attribute (#ha) and URL (#hu) escape helpers.

View:

module Users
  class Show
    include Lotus::Helpers

    def home_page_link
      %(<a href="#{ hu(user.home_page_url) }" title="#{ ha(user.name} }'s website">#{ h(user.website_name) }</a>)
    end

    def code_snippet
      raw user.code_snippet
    end
  end
end

Template:

<%= home_page_link %>
<%= code_snippet %>

Output:

<a href="https://example.org" title="Maria's website">My Blog</a>
<code>puts "Hello, World!"</code>

Routing Helper

Lotus and Lotus::Router integration (#routes).

View:

module Home
  class Index
    include Lotus::Helpers

    def link_to_home
      %(<a href="#{ routes.home_path }">Home</a>)
    end
  end
end

Template:

<%= link_to_home %>

Output:

<a href="/">Home</a>

Number Formatting Helper

Format numbers (#format_number).

View:

module Home
  class Index
    include Lotus::Helpers

    def visitors_count
      format_number '1000'
    end
  end
end

Template:

<p><%= visitors_count %></p>

Output:

<p>1,000</p>

Philosophy

All the Lotus helpers are modules to include.

Most of the time they inject private methods. This restriction prevents helper methods to be used on the outside (eg. in a template).

We want to encourage developers to use meaningful and simple APIs in their templates.

Bad style example

module Users
  class Show
    include Lotus::Helpers
  end
end

<%= format_number user.followers_count %>

This style increases the complexity of the template and it makes testing hard.

Good style example

module Users
  class Show
    include Lotus::Helpers

    def followers_count
      format_number user.followers_count
    end
  end
end

<%= followers_count %>

This simplifies the markup. In order to test the value that will be printed becomes easier: Users::Show#followers_count.

Versioning

Lotus::Helpers uses Semantic Versioning 2.0.0

Contributing

1. Fork it ( https://github.com/lotus/helpers/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request

Copyright

Copyright © 2014-2015 Luca Guidi – Released under MIT License