凤凰城中Rails的before_filter等效项 [英] Rails' before_filter equivalent in Phoenix

问题描述

我刚刚开始开发我的第一个Phoenix应用程序，问题是我的控制器中的每个动作中都有一些通用的代码行，我想将它们分开.他们从多个Ecto模型中获取数据，并将其保存到变量中以供使用.

I've just started working on my first Phoenix app, and the issue is that I have some common lines of code in every action in my controller, that I would like to separate out. They fetch data from multiple Ecto Models and save them to variables for use.

在Rails中，我可以简单地定义一个方法并在控制器中使用before_filter进行调用.我可以从@variable访问结果.我知道使用Plugs是关键，但是我不清楚如何实现这一点，更具体地说:

In Rails, I could simply define a method and call it using before_filter in my controller. I could access the result from an @variable. I understand that using Plugs is the key but I'm unclear on how to achieve this, more specifically:

• 从Plug
访问请求params
• 并使变量在操作中可访问

作为参考，这是我正在尝试做的Rails版本:

As a reference, this is the rails version of what i'm trying to do:

class ClassController < ApplicationController
    before_filter :load_my_models

    def action_one
        # Do something with @class, @students, @subject and @topics
    end

    def action_two
        # Do something with @class, @students, @subject and @topics
    end

    def action_three
        # Do something with @class, @students, @subject and @topics
    end

    def load_my_models
        @class    = Class.find    params[:class_id]
        @subject  = Subject.find  params[:subject_id]

        @students = @class.students
        @topics   = @subject.topics
    end
end

谢谢！

推荐答案

您确实可以使用Plug和

请记住要在操作插件之前添加插件声明，因为它们是按顺序执行的.

Remember to add the plug declaration before your action plug, as they are executed in-order.

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