```ruby
require "district_cn/version"
require "active_support/core_ext/module/delegation"
require "active_support/core_ext/object/blank"

module DistrictCn
  autoload :AsOptions, 'district_cn/as_options'
  autoload :Code,      'district_cn/code'
  autoload :Db,        'district_cn/db'

  begin
    if defined?(ActiveRecord)
      autoload :ActAsAreaField,'district_cn/act_as_area_field'
      ActiveRecord::Base.extend(ActAsAreaField::ActiveRecord)
    end
  rescue 
  end

  class << self

    def code(id)
      return id if id.blank?
      Code.new(id)
    end

    def search(text,limit=10)
      results = []
      list.each do |id,name|
        break if results.size.eql?(limit)

        if name =~ /#{text}/ 
          results << Code.new(id)
        end
      end
      results
    end

    delegate :provinces,:tree,:list, :to => Db::File 
  end

end
```

Fix return all cities when searching empty text
user
```ruby
require "district_cn/version"
require "active_support/core_ext/module/delegation"
require "active_support/core_ext/object/blank"

module DistrictCn
  autoload :AsOptions, 'district_cn/as_options'
  autoload :Code,      'district_cn/code'
  autoload :Db,        'district_cn/db'

  begin
    if defined?(ActiveRecord)
      autoload :ActAsAreaField,'district_cn/act_as_area_field'
      ActiveRecord::Base.extend(ActAsAreaField::ActiveRecord)
    end
  rescue 
  end

  class << self

    def code(id)
      return id if id.blank?
      Code.new(id)
    end

    def search(text,limit=10)
      results = []
      return results if text.empty?
      
      list.each do |id,name|
        break if results.size.eql?(limit)

        if name =~ /#{text}/ 
          results << Code.new(id)
        end
      end
      results
    end

    delegate :provinces,:tree,:list, :to => Db::File 
  end

end
```
assistant