haml helpers

bs_helpers.gemspec

# coding: utf-8
lib = File.expand_path('../lib', __FILE__)
$LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
require 'bs_helpers/version'

Gem::Specification.new do |spec|
  spec.name          = "bs_helpers"
  spec.version       = BsHelpers::VERSION
  spec.authors       = ["Tyrone Wilson"]
  spec.email         = ["tdubs241083@gmail.com"]
  spec.summary       = %q{BsHelpers is a gem which provide bootstrap components in a helper format}
  spec.description   = %q{I could never remember how to use the various tags etc for bootstrap. I also found it difficult to write responsive templates all the time remembering
                          to set the various, col classes on my divs. I found it easier to have helpers which provided simple defaults which I could override when I needed to.}
  spec.homepage      = ""
  spec.license       = "MIT"

  spec.files         = `git ls-files -z`.split("\x0")
  spec.executables   = spec.files.grep(%r{^bin/}) { |f| File.basename(f) }
  spec.test_files    = spec.files.grep(%r{^(test|spec|features)/})
  spec.require_paths = ["lib"]

  spec.add_development_dependency "bundler", "~> 1.7"
  spec.add_development_dependency "rake", "~> 10.0"
  spec.add_runtime_dependency "railties"
  spec.add_dependency "haml"
end

bs_helpers.rb

require "bs_helpers/version"
require "haml"
require "bs_helpers/railtie" if defined?(Rails)

module BsHelpers
  include Haml::Helpers
end

error trace

Started GET "/" for 127.0.0.1 at 2015-02-17 11:49:41 +0200
Processing by HomeController#index as HTML
  Rendered home/index.html.erb within layouts/application (2.2ms)
Completed 500 Internal Server Error in 12ms

ActionView::Template::Error (undefined method `capture_position=' for nil:NilClass):
    1: <h1>Home#index</h1>
    2: <p>Find me in app/views/home/index.html.erb</p>
    3: 
    4: <%= row %>
  app/views/home/index.html.erb:4:in `_app_views_home_index_html_erb__3877064646291024799_69955829171420'


  Rendered /home/tyrone/.rvm/gems/ruby-2.1.4/gems/actionpack-4.1.4/lib/action_dispatch/middleware/templates/rescues/_trace.html.erb (0.8ms)
  Rendered /home/tyrone/.rvm/gems/ruby-2.1.4/gems/actionpack-4.1.4/lib/action_dispatch/middleware/templates/rescues/_request_and_response.html.erb (0.8ms)
  Rendered /home/tyrone/.rvm/gems/ruby-2.1.4/gems/actionpack-4.1.4/lib/action_dispatch/middleware/templates/rescues/template_error.html.erb within rescues/layout (7.9ms

grid_helper.rb

module BsHelpers
  module GridHelper
    def row(tag: :div, **options, &block)
      capture_haml do
        haml_tag tag, class: "row #{options.fetch(:class, '')}" do
          yield
        end
      end
    end

    def col(tag: :div,sm: 12, md: sm/2, lg: md, xs: sm,  **options, &block)
      cls = "col-md-#{md} col-sm-#{sm} col-lg-#{lg} #{options.fetch(:class, '')}"
      capture_haml do
        haml_tag tag, class: cls, **options do
          yield
        end
      end
    end
  end
end

railtie.rb

#plug the helpers into rails with Railties
require 'bs_helpers/grid_helper'

module BsHelpers
  class Railtie < Rails::Railtie
    initializer "bs_helpers" do
      ActionView::Base.send :include, Haml::Helpers
      ActionView::Base.send :include, GridHelper
    end
  end
end