module ActiveAdmin::Inputs::Filters::Base::SearchMethodSelect

def self.included(base)
  base.extend ClassMethods
end

def current_filter
  @current_filter ||= begin
    methods = filters.map { |f| "#{method}_#{f}" }
    methods.detect { |m| @object.public_send m } || methods.first
  end
end

def filter_options
  filters.collect do |filter|
    [I18n.t("active_admin.filters.predicates.#{filter}"), "#{method}_#{filter}"]
  end
end

def filters
  options[:filters] || self.class.filters
end

def input_html
  builder.text_field current_filter, input_html_options
end

def select_html
  template.select_tag "", template.options_for_select(filter_options, current_filter)
end

def to_html
  input_wrapping do
    label_html << # your label
    select_html << # the dropdown that holds the available search methods
    input_html # your input field
  end
end

def wrapper_html_options
  opts = super
  (opts[:class] ||= "") << " select_and_search" unless seems_searchable?
  opts
end