Rails |拯救模型中的异常并使用控制器中的错误

Question

我正在使用 twitter gem 来允许用户从我的应用程序 post 推文。

这是我的 tweet.rb 文件

 class Tweet < ActiveRecord::Base
     belongs_to :user

     validates :user_id, :tweet, presence: true
     before_create :post_to_twitter

     def post_to_twitter
       begin
        user.twitter.update(tweet)
       rescue Twitter::Error => error
        // I want to do a redirect_to root_path, notice: "Please fix the error #{error.message}"
       // but its against MVC structure to pattern for a model to redirect, since its the task of a controller. How can I achieve this in controller
       end
     end
    end

在post_to_twitter方法的救援块中，我想做一个redirect_to root_path, notice: "Please fix the error #{error.message}" 但它反对 MVC 结构来模式化模型重定向，因为它是控制器的任务。我怎样才能在控制器中实现这一点？

这是tweets_controller.rb个文件

class TweetsController < ApplicationController

      def new
        @tweet = Tweet.new
      end

      def create
        @tweet = Tweet.new(tweet_params)
        @tweet.user_id = current_user.id
        if @tweet.save
          redirect_to new_tweet_path, notice: "Your tweet has been successfully posted"
        else
          render 'new'
        end
      end

      private
      def tweet_params
        params.require(:tweet).permit(:tweet, :user_id)
      end

    end

Answer 1

你可以在回调不成功时给对象添加错误：

def post_to_twitter
  begin
    user.twitter.update(tweet)
  rescue Twitter::Error => error
    # error will be appear in `@tweet.errors`
    errors.add(:base, "Please fix the error #{error.message}")
    false
  end
end

然后，当 @tweet.save returns false 时，在控制器中做任何你需要的事情（并且它将 return false 因为回调不成功）：

def create
  @tweet = Tweet.new(tweet_params)
  @tweet.user_id = current_user.id
  if @tweet.save
    redirect_to new_tweet_path, notice: "Your tweet has been successfully posted"
  else
    # render 'new'
    redirect_to root_path, notice: @tweet.errors.full_messages.join(',')
  end
end

Answer 2

在控制器中使用rescue_from来捕获错误：

class TweetsController

  rescue_from Twitter::Error, with: :error

  def error
    redirect_to root_path, alert: "Please fix the error #{error.message}"
  end
end

此外，如果您想同时捕获模型和控制器中的错误，您可以通过重新引发来实现：

class Tweet < ActiveRecord::Base
  belongs_to :user

  validates :user_id, :tweet, presence: true
  before_create :post_to_twitter

  def post_to_twitter
   begin
     user.twitter.update(tweet)
   rescue Twitter::Error => error
     self.twottered = false
     raise error
   end
  end
end

Rails |拯救模型中的异常并使用控制器中的错误

Rails | Rescue exception in model and use the error in controller

twitter

ruby-on-rails

rescue