会话是 Rails 中的方法还是哈希?有点糊涂 [英] Is session a method or hash in Rails? Slightly confused

问题描述

有一个非常简单的问题.我正在做 Michael Hartl 的 railstutorial，它谈到了使用 session 方法:

Got a really simple question. I'm doing the railstutorial by Michael Hartl and it talks about using the session method:

在 Rails 定义的 session 方法的帮助下，登录用户很简单......我们可以将 session 视为一个散列，并按如下方式分配给它:

Logging a user in is simple with the help of the session method defined by Rails... We can treat session as if it were a hash, and assign to it as follows:

session[:user_id] = user.id

它说你可以把 session 当作一个散列来对待，但我很困惑，因为它被称为 session 方法，所以实际上有什么被调用的吗?我的猜测是，通过插入会话哈希，有一个会话函数可以查看哈希以查看是否存在任何内容?我不太确定它是如何工作的.

It says you can treat session as if it were a hash, but I'm confused because it is called the session method, so is anything actually being called? My guess is that by inserting into the session hash, there is a session function that looks into the hash to see if there is anything present? I'm not really sure how it works.

推荐答案

不提Session 文档:

所有会话存储使用 cookie 来存储每个会话的唯一 ID(您必须使用 cookie，Rails 不允许您在 URL 中传递会话 ID，因为这样不太安全).

All session stores use a cookie to store a unique ID for each session (you must use a cookie, Rails will not allow you to pass the session ID in the URL as this is less secure).

基本上，每次有人访问您的 Rails 应用时，它都会在他们的浏览器中创建一个小 cookie，可通过唯一 ID(不是用户 ID)进行识别.

Basically, each time someone visits your Rails app, it will create a small cookie in their browser, identifiable by a unique ID (not user ID).

这个 cookie 本质上是一个 Ruby 哈希，因此你可以在其中存储哈希数据:

This cookie is essentially a Ruby hash, hence why you can store hashed data inside it:

session[:your_hash] = "TEST"

这将允许您通过请求存储小数据片段(例如 user_id 或其他).

This will allow you to store small snippets of data (such as user_id or others) through requests.

Rails 有这个的主要原因归结为 HTTP 是一个 无状态协议.

The main reason Rails has this is down to HTTP being a stateless protocol.

无状态协议与有状态协议相反；它们不保留请求之间的状态，因此每次访问应用程序的新实例时，您都必须重新调用数据等.

Stateless protocols are contrary to stateful protocols; they don't retain the state between requests, thus you have to reinvoke data, etc, each time a new instance of the application is accessed.

简单地说，这意味着 Rails 是一个愚蠢"的系统——只记住你每次请求发送的数据.会话变量几十年来一直被开发人员用来提供有关用户/偏好等的基本信息，允许您针对每个请求重建"一个用户.

Simply, this translates into Rails being a "dumb" system - only remembering data you send it each request. Session variables have been used by developers for decades to provide base information about users / preferences etc, allowing you to "rebuild" a user with each request.

这就是您必须将 user_id 保存为会话的原因 - 每次您希望引用登录用户的数据时，都必须从该 id 构建> 存储在会话哈希中.

This is why you have to save the user_id as a session - each time you wish to reference a logged-in user's data, it has to be built from that id stored in the sessions hash.

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