问题描述
Rails 4 文档中所有强参数的例子都使用
All the examples of strong parameters in Rails 4 docs use
params.require(:person).permit(:name, :age)
有人可以解构并解释这里的 require 和 permit 发生了什么吗?
Could someone please deconstruct and explain what is occurring with require and permit here?
推荐答案
控制器中的 params 看起来像一个 Hash，但它实际上是 ActionController::Parameters，它提供了多种方法，例如require和permit.
The params in a controller looks like a Hash, but it's actually an instance of ActionController::Parameters, which provides several methods such as require and permit.
require 方法确保特定参数存在，如果没有提供，require 方法会抛出错误.它返回一个 ActionController::Parameters 的实例，用于传递给 require 的键.
The require method ensures that a specific parameter is present, and if it's not provided, the require method throws an error. It returns an instance of ActionController::Parameters for the key passed into require.
permit 方法返回一个副本参数对象，只返回允许的键和值.创建新的 ActiveRecord 模型时，仅将允许的属性传递到模型中.
The permit method returns a copy of the parameters object, returning only the permitted keys and values. When creating a new ActiveRecord model, only the permitted attributes are passed into the model.
它看起来很像以前包含在 ActiveRecord 模型中的白名单，但将其包含在控制器中更有意义.
It looks a lot like the whitelisting that was formerly included in ActiveRecord models, but it makes more sense for it to be in the controller.
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