在Rails控制器中捕获所有异常

有没有办法在Rails控制器中捕获所有未捕获的异常，如下所示：

def delete
  schedule_id = params[:scheduleId]
  begin
    Schedules.delete(schedule_id)
  rescue ActiveRecord::RecordNotFound
    render :json => "record not found"
  rescue ActiveRecord::CatchAll
    #Only comes in here if nothing else catches the error
  end
  render :json => "ok"
end

谢谢

begin
  # do something dodgy
rescue ActiveRecord::RecordNotFound
  # handle not found error
rescue ActiveRecord::ActiveRecordError
  # handle other ActiveRecord errors
rescue # StandardError
  # handle most other errors
rescue Exception
  # handle everything else
  raise
end

您也可以定义rescue_from方法。

class ApplicationController < ActionController::Base
  rescue_from ActionController::RoutingError, :with => :error_render_method

  def error_render_method
    respond_to do |type|
      type.xml { render :template => "errors/error_404", :status => 404 }
      type.all  { render :nothing => true, :status => 404 }
    end
    true
  end
end

根据您的目标，您可能还想考虑不按每个控制器处理异常。而是使用exception_handler gem之类的东西来统一管理对异常的响应。另外，这种方法还将处理中间件层发生的异常，例如请求解析或应用程序看不到的数据库连接错误。该exception_notifier宝石也可能会感兴趣。

您可以按类型捕获异常：

rescue_from ::ActiveRecord::RecordNotFound, with: :record_not_found
rescue_from ::NameError, with: :error_occurred
rescue_from ::ActionController::RoutingError, with: :error_occurred
# Don't resuce from Exception as it will resuce from everything as mentioned here "http://stackoverflow.com/questions/10048173/why-is-it-bad-style-to-rescue-exception-e-in-ruby" Thanks for @Thibaut Barrère for mention that
# rescue_from ::Exception, with: :error_occurred 

protected

def record_not_found(exception)
  render json: {error: exception.message}.to_json, status: 404
  return
end

def error_occurred(exception)
  render json: {error: exception.message}.to_json, status: 500
  return
end

rescue 没有参数将挽救任何错误。

因此，您需要：

def delete
  schedule_id = params[:scheduleId]
  begin
    Schedules.delete(schedule_id)
  rescue ActiveRecord::RecordNotFound
    render :json => "record not found"
  rescue
    #Only comes in here if nothing else catches the error
  end
  render :json => "ok"
end

实际上，如果您真的想捕获所有内容，则只需创建自己的异常应用程序，即可自定义通常由PublicExceptions中间件处理的行为：https : //github.com/rails/rails/blob/4-2 -stable / actionpack / lib / action_dispatch / middleware / public_exceptions.rb

• 堆栈中的位置https://github.com/rails/rails/blob/4-2-stable/railties/lib/rails/application/default_middleware_stack.rb#L98-L99
• 配置https://github.com/rails/rails/blame/4-2-stable/guides/source/configuring.md#L99
  • 就像使用路线http://blog.plataformatec.com.br/2012/01/my-five-favorite-hidden-features-in-rails-3-2/或自定义控制器一样简单（但请参见https://github.com/rails/rails/pull/17815（出于不使用路线的原因）

许多其他答案共享可以为您做到这一点的宝石，但实际上没有理由您不能只看它们自己做。

警告：请确保您从未在异常处理程序中引发异常。否则您会收到一个难看的FAILSAFE_RESPONSE https://github.com/rails/rails/blob/4-2-stable/actionpack/lib/action_dispatch/middleware/show_exceptions.rb#L4-L22

顺便说一句，控制器中的行为来自可修复的：https : //github.com/rails/rails/blob/4-2-stable/activesupport/lib/active_support/rescuable.rb#L32-L51