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:

ruby gem 'lotus-helpers'

And then execute:

shell $ bundle

Or install it yourself as:

shell $ gem install lotus-helpers

Usage

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

HTML helper

HTML5 markup generator (#html).

View:

```ruby 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:

erb <%= sidebar %>

Output:

```html

Languages

• Italian
• English

```

Form Helper

Form generator for HTML5 (#form_for)

Template Usage

Template:

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

submit 'Create'   end %> ```

Output:

```html

Create

```

View Usage

View:

```ruby 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:

erb <%= form %>

Output:

```html

Create

```

Reuse Code

Views:

```ruby 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:

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

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

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

submit submit_label   end %> ```

Output for new:

```html

Create

```

Output for edit:

```html

Update

```

Escape helper

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

View:

```ruby 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:

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

Output:

html <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:

```ruby module Home class Index include Lotus::Helpers

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

Template:

erb <%= link_to_home %>

Output:

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

Number Formatting Helper

Format numbers (#format_number).

View:

```ruby module Home class Index include Lotus::Helpers

def visitors_count
  format_number '1000'
end   end end ```

Template:

```erb

<%= visitors_count %>

```

Output:

```html

1,000

```

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

ruby module Users class Show include Lotus::Helpers end end

erb <%= format_number user.followers_count %>

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

Good style example

```ruby module Users class Show include Lotus::Helpers

def followers_count
  format_number user.followers_count
end   end end ```

erb <%= 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 © 2014-2016 Luca Guidi – Released under MIT License