def input_field(attribute_name, options = {})
      components = (wrapper.components.map(&:namespace) & ATTRIBUTE_COMPONENTS)

      options = options.dup
      options[:input_html] = options.except(:as, :boolean_style, :collection, :disabled, :label_method, :value_method, :prompt, *components)
      options = @defaults.deep_dup.deep_merge(options) if @defaults

      input      = find_input(attribute_name, options)
      wrapper    = find_wrapper(input.input_type, options)
      components = build_input_field_components(components.push(:input))

      SimpleForm::Wrappers::Root.new(components, wrapper.options.merge(wrapper: false)).render input
    end
def input_field(attribute_name, options = {})
      components = (wrapper.components.map(&:namespace) & ATTRIBUTE_COMPONENTS)

      options = options.dup
      options[:input_html] = options.except(:as, :boolean_style, :collection, :disabled, :label_method, :value_method, :prompt, *components)
      options = @defaults.deep_dup.deep_merge(options) if @defaults

      input      = find_input(attribute_name, options)
      wrapper    = find_wrapper(input.input_type, options)
      components = build_input_field_components(components.push(:input))

      SimpleForm::Wrappers::Root.new(components, wrapper.options.merge(wrapper: false)).render input
    end
Creates a input tag for the given attribute. All the given options
 are sent as :input_html.

 == Examples

   simple_form_for @user do |f|
     f.input_field :name
   end

 This is the output html (only the input portion, not the form):

     <input class="string required" id="user_name" maxlength="100"
        name="user[name]" type="text" value="Carlos" />

 It also support validation classes once it is configured.

   # config/initializers/simple_form.rb
   SimpleForm.setup do |config|
     config.input_field_valid_class = 'is-valid'
     config.input_field_error_class = 'is-invalid'
   end

   simple_form_for @user do |f|
     f.input_field :name
   end

 When the validation happens, the input will be rendered with
 the class configured according to the validation:

 - when the input is valid:

     <input class="is-valid string required" id="user_name" value="Carlos" />

 - when the input is invalid:

     <input class="is-invalid string required" id="user_name" value="" />