处理控制器中的唯一记录异常 [英] Handling Unique Record Exceptions in a Controller

问题描述

我有一个名为Subscription的模型，在[：email，：location]字段上有唯一的索引。这意味着一个电子邮件地址可以每个位置订阅。

I have a model called Subscription that has a unique index on the fields [:email, :location]. This means one email address can subscribe per location.

在我的模型中：

class Subscription < ActiveRecord::Base
  validates :email, :presence => true, :uniqueness => true, :email_format => true, :uniqueness => {:scope => :location}
end

在我的创建方法中。我想处理例外 ActiveRecord :: RecordNotUnique 不同于常规错误。我如何添加到这个通用的创建方法？

In my create method. I want to handle the the exception ActiveRecord::RecordNotUnique differently than a regular error. How would I add that in to this generic create method?

  def create
    @subscription = Subscription.new(params[:subscription])
    respond_to do |format|
      if @subscription.save
        format.html { redirect_to(root_url, :notice => 'Subscription was successfully created.') }
      else
        format.html { render :action => 'new' }
      end
    end
  end

推荐答案

我不认为只有一种类型的验证失败才会有异常抛出。您可以执行 save！，这将引发所有保存错误（包括所有验证错误）的异常，并将它们单独处理。

I don't think there is a way to have an exception thrown just for a single type of validation failure. Either you can do a save! which would raise exceptions for all save errors (including all validation errors) and have them handled separately.

您可以做的是处理异常 ActiveRecord :: RecordInvalid 并将异常消息与进行匹配验证失败：电子邮件已被采用然后单独处理。但是这也意味着你也必须处理其他错误。

What you can do is handle the exception ActiveRecord::RecordInvalid and match the exception message with Validation failed: Email has already been taken and then handle it separately. But this also means that you would have to handle other errors too.

某些东西，

begin
  @subscription.save!
rescue ActiveRecord::RecordInvalid => e
  if e.message == 'Validation failed: Email has already been taken'
    # Do your thing....
  else
    format.html { render :action => 'new' }
  end
end
format.html { redirect_to(root_url, :notice => 'Subscription was successfully created.') }

我不知道这是否是唯一的解决方案。

I'm not sure if this is the only solution to this though.

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