在Rails cookie中存储/检索值 [英] Storing/Retrieving values in a Rails cookie

问题描述

我创建了一个SessionHelper模块，其外观大致如下：

I created a SessionHelper module which looks more or less like this:

module SessionHelper

  def create_cookie
      cookies.signed[:token] = {
      :value => [],
      :expires => 1.hour.from_now
      }
  end

  def cookie_values
      cookies.signed[:token]
  end

  def add_value_to_cookie(value)
      cookies[:token] << value
  end

  def cookie_exists?
      cookies[:token].present?
  end

end

然后将其包含到应用程序中控制器，并在每个请求之前在过滤器中触发：

It then gets included to the Application controller and gets fired in a filter, before every request:

create_cookie unless cookie_exists?

我的网站未使用身份验证，我想显示访客最近创建的项目。
因此，在Item控制器中，我有这样的东西：

My site does not use authentication, I would like to display the recent items that were created by a guest. So, in an Item controller I have something like this:

def create
  @item=Item.new(params[:item])
  if @item.save 
     add_value_to_cookie(@item.id)
     redirect_to @item
  else
     render :new
  end
end

问题如下：

• 之前的过滤器创建一个空的
  cookie，我可以确认它的初始
  值设置为[]（确定）


• 用户创建项目后，我希望cookie数组具有附加值，但相反它将变为Nil，并且没有任何内容（BAD）。它甚至不会引发异常。

我在哪里出错？我应该如何向cookie添加新值？
另外，检查cookie是否存在的首选方法是什么？似乎#has_key？方法不可用。

Where do I made an error?. How should I add new values to the cookie? Additionally, what is the prefered way to check the existance of a cookie? It seems that the #has_key? method is not available.

一些附带问题：

因为我要显示来宾项目的链接（存储在Cookie中） ，其形式为：

Since I want to display links to the guest's items (stored in the cookie), which would have the form of:

link_to @item.title, item_path(@item.id)

然后我应该在#create动作中创建链接并将其存储在cookie中吗？还是应该仅保留我所知道的ID来生成它们？我担心cookie可能无法存储此类链接（因此我最初想到的是仅存储ID）

Should I then just make the links in the #create action and store them in the cookie? Or should I keep just the IDs as I do know, to generate them? I am concerned that a cookie might not be able to store such links (thus I initially thought of storing just IDs)

预先感谢

编辑：似乎不可能将cookie用作数组，并且解决方法是使用某种形式的序列化。我选择了JSON

Seems like it is not possible to use a cookie as an array, and the workaround is to use some form of serialization. I settled on JSON

module SessionHelper

  def set_user_cookie
    cookies.signed[:token] = {
        :value => [].to_json,
        :expires => 1.hour.from_now
    }
  end

  def user_cookie_values
    load_user_cookie_data
  end


  def user_cookie_exists?
        cookies[:token].present?
  end

  def add_to_user_cookie(value)
    current = load_user_cookie_data
    current << value
    cookies.signed[:token] = current.to_json
  end

  def remove_from_user_cookie(value)
    current = load_user_cookie_data
    current.delete(value)
    cookies.signed[:token] = current.to_json
  end

  private

  def load_user_cookie_data
    JSON.load(cookies.signed[:token])
  end

end

尽管我仍然会对听到在cookie中存储内容的首选方式感兴趣。纯粹的ID或链接？

Although I'd still be interested in hearing what is the preferred way of storing content in the cookie. Pure IDs or Links?

推荐答案

我最近遇到了一个类似的问题，并通过创建一个隐藏所有cookie的CookieCollection类来解决了该问题哈希交互，并允许您像使用数组一样从集合中添加和列出。通过控制器方法和辅助程序公开。

I recently ran into a similar issue and solved it by creating a CookieCollection class that hides all the cookie hash interaction and allows you to add and list from the collection like you would with an Array. It's exposed through a controller method and helper.

http://www.swards.net/2013/08/cookie-collection-objects.html

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