simple_form 3.0.1 bootstrap 3 config and custom input.

_form.html.erb

<%%= simple_form_for(@<%= singular_table_name %>) do |f| %>
  <%%= f.error_notification %>

  <div class="form-inputs">
  <%- attributes.each do |attribute| -%>
    <%%= f.<%= attribute.reference? ? :association : :input %> :<%= attribute.name %> %>
  <%- end -%>
  </div>

  <div class="form-actions form-group">
    <div class="col-sm-offset-3 col-sm-9">
      <%%= f.button :submit %>
    </div>
  </div>
<%% end %>

bootstrap_boolean_input.rb

class BootstrapBooleanInput < SimpleForm::Inputs::BooleanInput
  def input
    build_hidden_field_for_checkbox +
      template.content_tag(:div, class: "checkbox") {
        template.label_tag(nil) {
          build_check_box_without_hidden_field + label_text
        }
      }
  end

  def label_input
    input
  end

  def input_html_classes
    classes = super
    classes.delete('form-control')
    classes
  end
end

simple_form.rb

# Use this setup block to configure all options available in SimpleForm.
SimpleForm.setup do |config|
  # Wrappers are used by the form builder to generate a
  # complete input. You can remove any component from the
  # wrapper, change the order or even add your own to the
  # stack. The options given below are used to wrap the
  # whole input.
  config.wrappers :default, class: :input,
    hint_class: :field_with_hint, error_class: :field_with_errors do |b|
    ## Extensions enabled by default
    # Any of these extensions can be disabled for a
    # given input by passing: `f.input EXTENSION_NAME => false`.
    # You can make any of these extensions optional by
    # renaming `b.use` to `b.optional`.

    # Determines whether to use HTML5 (:email, :url, ...)
    # and required attributes
    b.use :html5

    # Calculates placeholders automatically from I18n
    # You can also pass a string as f.input placeholder: "Placeholder"
    b.use :placeholder

    ## Optional extensions
    # They are disabled unless you pass `f.input EXTENSION_NAME => :lookup`
    # to the input. If so, they will retrieve the values from the model
    # if any exists. If you want to enable the lookup for any of those
    # extensions by default, you can change `b.optional` to `b.use`.

    # Calculates maxlength from length validations for string inputs
    b.optional :maxlength

    # Calculates pattern from format validations for string inputs
    b.optional :pattern

    # Calculates min and max from length validations for numeric inputs
    b.optional :min_max

    # Calculates readonly automatically from readonly attributes
    b.optional :readonly

    ## Inputs
    b.use :label_input
    b.use :hint,  wrap_with: { tag: :span, class: :hint }
    b.use :error, wrap_with: { tag: :span, class: :error }
  end

  # The default

simple_form_bootstrap.rb

# Use this setup block to configure all options available in SimpleForm.
SimpleForm.setup do |config|
  config.wrappers :bootstrap, tag: 'div', class: 'control-group form-group', error_class: 'has-error' do |b|
    b.use :html5
    b.use :placeholder
    b.use :label
    b.wrapper tag: 'div', class: 'controls col-sm-6' do |ba|
      ba.use :input
      ba.use :error, wrap_with: { tag: 'span', class: 'help-inline' }
      ba.use :hint,  wrap_with: { tag: 'p', class: 'help-block' }
    end
  end

  config.wrappers :bootstrap_boolean, tag: 'div', class: 'control-group form-group', error_class: 'has-error' do |b|
    b.use :html5
    b.wrapper tag: 'div', class: 'controls col-sm-offset-3 col-sm-9' do |ba|
      ba.use :input
      ba.use :error, wrap_with: { tag: 'span', class: 'help-inline' }
      ba.use :hint,  wrap_with: { tag: 'p', class: 'help-block' }
    end
  end

  config.wrappers :prepend, tag: 'div', class: "control-group form-group", error_class: 'has-error' do |b|
    b.use :html5
    b.use :placeholder
    b.use :label
    b.wrapper tag: 'div', class: 'controls col-sm-6 input-group' do |input|
      input.wrapper tag: 'div', class: 'input-group-addond' do |prepend|
        prepend.use :input
      end
      input.use :hint,  wrap_with: { tag: 'span', class: 'help-block' }
      input.use :error, wrap_with: { tag: 'span', class: 'help-inline' }
    end
  end

  config.wrappers :append, tag: 'div', class: "control-group form-group", error_class: 'has-error' do |b|
    b.use :html5
    b.use :placeholder
    b.use :label
    b.wrapper tag: 'div', class: 'controls col-sm-6 input-group' do |input|
      input.wrapper tag: 'div', class: 'input-group-addon' do |append|
        append.use :input
      end
      input.use :hint,  wrap_with: { tag: 'span', class: 'help-block' }
      input.use :error, wrap_with: { tag: 'span', class: 'help-inline' }
    end
  end

  # Wrappers for forms and inputs using the Twitter Bootstrap toolkit.
  # Check the Bootstrap docs (http://twitter.github.com/bootstrap)
  # to learn about the different styles for forms and inputs,
  # buttons and other elements.
  config.default_wrapper = :bootstrap
end

Latest gist: https://gist.github.com/donnykurnia/9267948