rails 方法小结

###Rails在Controller中使用helper方法
view_context.link_to "link", "http://www.baidu.com"

or

ActionController::Base.helpers.link_to "link", "http://www.baidu.com"

each_with_object

###old_hash.each_with_object(初期化object) {|item, new_hash| block処理 }


smile = { vocal:'tim', guitar:'brian', bass:'tim', drum:'roger' }

queen = smile.each_with_object({}) do |(key, val), member|
  member[key.to_sym] =
  case key
  when :vocal
    member[:vocal] = 'fleddie'
  when :bass
    member[:bass] = 'jhon'
  else
    val
  end
end

inject

###old_hash.inject(初期化object) {|new_hash, item| block処理 }


smile = { vocal:'tim', guitar:'brian', bass:'tim', drum:'roger' }

queen = smile.inject({}) do |member, (key, val)|
  member[key.to_sym] =
    case key
    when :vocal
      member[:vocal] = 'fleddie'
    when :bass
      member[:bass] = 'jhon'
    else
      val
    end
  member   #injectの場合、ブロックでループする最後に作成中のhashを返す行が必要
end