MVC架构在Rails中的简要流程

先上图：

从图中可以看出，从浏览器请求到控制器响应一段代码给浏览器，整个流程一般情况下为8步：

1. The browser issues a request for the /users URI.
2. Rails routes /users to the index action in the Users controller.
3. The index action asks the User model to retrieve all users (User.all).
4. The User model pulls all the users from the database.
5. The User model returns the list of users to the controller.
6. The controller captures the users in the @users variable, which is passed to theindex view.
7. The view uses embedded Ruby to render the page as HTML.
8. The controller passes the HTML back to the browser.³