simple_form bootstrap 2.0.x :span component

Easily set the width of inputs in twitter bootstrap

module SimpleForm
  module DoneComponents
    module Span
      def span
        if options[:span]
          input_html_classes << 'input-block-level'
          options[:wrapper_html] ||= {}
          options[:wrapper_html][:class] ||= ""
          options[:wrapper_html][:class] <<= " #{options[:span]}"
        end

        # Return value is output directly, so return nil
        nil
      end
    end
  end
end

class SimpleForm::Inputs::Base
  include SimpleForm::DoneComponents::Span
end

I just put this at the bottom of config/initializers/simple_form.rb and then replace

f.input :item, :wrapper_html => { :class => 'span3' }, :input_html => { :class => 'input-block-level' }

with

f.input :span => 'span2'

Works with fluid and fixed grids.