label - Modifying the simple_form lable -

i need add span in label being generated simpleform. goal able use this coffeescript validate field presence.

currently looks like:

<div class="control-group form-group string optional dealer_website">   <label class="string optional control-label" for="dealer_website">     website   </label>   <div class="controls">     <input class="string optional form-control" id="dealer_website" name="dealer[website]" size="50" type="text">   </div> </div> 

i need like:

<div class="control-group form-group string optional dealer_website">   <label class="string optional control-label" for="dealer_website">     website     <span class="error-message"></span>   </label>   <div class="controls">     <input class="string optional form-control" id="dealer_website" name="dealer[website]" size="50" type="text">   </div> </div> 

here simple_form_bootstrap.rb

# use setup block configure options available in simpleform. simpleform.setup |config|    config.wrappers :bootstrap, :tag => 'div', :class => 'control-group form-group', :error_class => 'error' |b|     b.use :html5     b.use :placeholder     b.use :label     b.wrapper :tag => 'div', :class => 'controls' |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", :error_class => 'error' |b|     b.use :html5     b.use :placeholder     b.use :label     b.wrapper :tag => 'div', :class => 'controls' |input|       input.wrapper :tag => 'div', :class => 'input-prepend' |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", :error_class => 'error' |b|     b.use :html5     b.use :placeholder     b.use :label     b.wrapper :tag => 'div', :class => 'controls' |input|       input.wrapper :tag => 'div', :class => 'input-append' |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 forms , inputs using twitter bootstrap toolkit.   # check bootstrap docs (http://twitter.github.com/bootstrap)   # learn different styles forms , inputs,   # buttons , other elements.   config.default_wrapper = :bootstrap end 

and here simple_form.rb

# use setup block configure options available in simpleform. simpleform.setup |config|   # wrappers used form builder generate   # complete input. can remove component   # wrapper, change order or add own   # stack. options given below used wrap   # whole input.   config.wrappers :default, :class => :input,     :hint_class => :field_with_hint, :error_class => :field_with_errors |b|      ## extensions enabled default     # of these extensions can disabled     # given input passing: `f.input extension_name => false`.     # can make of these extensions optional     # renaming `b.use` `b.optional`.      # determines whether use html5 (:email, :url, ...)     # , required attributes     b.use :html5      # calculates placeholders automatically i18n     # can pass string f.input :placeholder => "placeholder"     b.use :placeholder      ## optional extensions     # disabled unless pass `f.input extension_name => :lookup`     # input. if so, retrieve values model     # if exists. if want enable lookup of     # extensions default, can change `b.optional` `b.use`.      # calculates maxlength length validations string inputs     b.optional :maxlength      # calculates pattern format validations string inputs     b.optional :pattern      # calculates min , max length validations numeric inputs     b.optional :min_max      # calculates readonly automatically 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    # default wrapper used formbuilder.   config.default_wrapper = :default    # define way render check boxes / radio buttons labels.   # defaults :nested bootstrap config.   #   :inline => input + label   #   :nested => label > input   config.boolean_style = :nested    # default class buttons   config.button_class = 'btn'    # method used tidy errors. specify rails array method.   # :first lists first message each field.   # use :to_sentence list errors each field.   # config.error_method = :first    # default tag used error notification helper.   config.error_notification_tag = :div    # css class add error notification helper.   config.error_notification_class = 'alert alert-error'    # id add error notification helper.   # config.error_notification_id = nil    # series of attempts detect default label method collection.   # config.collection_label_methods = [ :to_label, :name, :title, :to_s ]    # series of attempts detect default value method collection.   # config.collection_value_methods = [ :id, :to_s ]    # can wrap collection of radio/check boxes in pre-defined tag, defaulting none.   # config.collection_wrapper_tag = nil    # can define class use on collection wrappers. defaulting none.   # config.collection_wrapper_class = nil    # can wrap each item in collection of radio/check boxes tag,   # defaulting :span. please note when using :boolean_style = :nested,   # simpleform force option label.   # config.item_wrapper_tag = :span    # can define class use in item wrappers. defaulting none.   # config.item_wrapper_class = nil    # how label text should generated altogether required text.   # config.label_text = lambda { |label, required| "#{required} #{label}" }    # can define class use on labels. default nil.   config.label_class = 'control-label'     # can define class use on forms. default simple_form.   # config.form_class = :simple_form    # can define elements should obtain additional classes   # config.generate_additional_classes_for = [:wrapper, :label, :input]    # whether attributes required default (or not). default true.   # config.required_by_default = true    # tell browsers whether use default html5 validations (novalidate option).   # default enabled.   config.browser_validations = false    # collection of methods detect if file type given.   # config.file_methods = [ :mounted_as, :file?, :public_filename ]    # custom mappings input types. should hash containing regexp   # match key, , input type used when field name   # matches regexp value.   # config.input_mappings = { /count/ => :integer }    # custom wrappers input types. should hash containing input   # type key , wrapper used inputs specified type.   # config.wrapper_mappings = { :string => :prepend }    # default priority time_zone inputs.   # config.time_zone_priority = nil    # default priority country inputs.   # config.country_priority = ["pakistan"]    # default size text inputs.   # config.default_input_size = 50    # when false, not use translations labels.   # config.translate_labels = true    # automatically discover new inputs in rails' autoload path.   # config.inputs_discovery = true    # cache simpleform inputs discovery   # config.cache_discovery = !rails.env.development?   end