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我已经在这个问题上停留了一段时间，但一直跳过它。如果我遵循此处的警察指南并将其更改为 && 我的路线中断。它们通过以下方式连接到我的路线：

  # Override Error Codes
  match '/404', to: 'error#four_oh_four', via: :all
  match '/422', to: 'error#four_twenty_two', via: :all
  match '/500', to: 'error#five_hundred', via: :all

您是否建议为此问题禁用此警察，或者是否有更好的方法来调整它？

在此处输入图像描述

class ErrorController < ApplicationController
  before_filter :ensure_trailing_slash
  before_action :load_log_service

  def javascript_disabled
    @log_service.capture_message(view_context.time_stamp('javascript_disabled'), 'error_scope')
    render_error_application_requirements t('system_requirements.minimum_settings.javascript_disabled')
  end

  def system_requirements
    @log_service.capture_message(view_context.time_stamp('system_requirements'), 'error_scope')
    render_error_application_requirements t('system_requirements.minimum_settings.system_requirements')
  end

  def browser_upgrade_required
    @log_service.capture_message(view_context.time_stamp('browser_upgrade_required'), 'error_scope')
    render_error_application_requirements t('system_requirements.minimum_settings.browser_upgrade_required')
  end

  def four_oh_four
    @log_service.capture_message(view_context.time_stamp('four_oh_four'), 'error_code')
    render_error_status_code('Page Not Found', '404', t('system_requirements.response_code.four_oh_four'))
  end

  # four_twenty_two, five_hundred :: no custom report needed, they are picked up by the sentry gem
  def four_twenty_two
    render_error_status_code('Application Error', '422', t('system_requirements.response_code.four_twenty_two'))
  end

  def five_hundred
    render_error_status_code('Application Error', '500', t('system_requirements.response_code.five_hundred'))
  end

  private

  def render_error_application_requirements(title)
    @title = title
    render 'errors/application_requirements', layout: 'errors/application_requirements' and return
  end

  def render_error_status_code(title, error_code, error_msg)
    @title = title
    @error_code = error_code
    @error_msg = error_msg
    render 'errors/status_code', layout: 'errors/status_code', status: @error_code and return
  end

  def load_log_service
    @log_service = LogService.new
  end
end
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2 回答 2

4

我认为您在render这里调用的论点缺乏括号会让您感到困惑。&&具有更高and的优先级，不同之处在于改变 Ruby 将参数标识为render.

猜测并不好玩，让我们确定一下。MRI Ruby 包括Ripper允许我们检查如何解析表达式。

require 'ripper'
require 'pp'

和

Ripper.sexp("render 'errors/application_requirements', layout: 'errors/application_requirements' and return")

[:program,
 [[:binary,
   [:command,
    [:@ident, "render", [1, 0]],
    [:args_add_block,
     [[:string_literal,
       [:string_content, [:@tstring_content, "errors/status_code", [1, 8]]]],
      [:bare_assoc_hash,
       [[:assoc_new,
         [:@label, "layout:", [1, 29]],
         [:string_literal,
          [:string_content,
           [:@tstring_content, "errors/status_code", [1, 38]]]]],
        [:assoc_new,
         [:@label, "status:", [1, 59]],
         [:var_ref, [:@ivar, "@error_code", [1, 67]]]]]]],
     false]],
   :and,
   [:return0]]]]

&&

Ripper.sexp("render 'errors/application_requirements', layout: 'errors/application_requirements' && return")

[:program,
 [[:command,
   [:@ident, "render", [1, 0]],
   [:args_add_block,
    [[:string_literal,
      [:string_content, [:@tstring_content, "errors/status_code", [1, 8]]]],
     [:bare_assoc_hash,
      [[:assoc_new,
        [:@label, "layout:", [1, 29]],
        [:string_literal,
         [:string_content,
          [:@tstring_content, "errors/status_code", [1, 38]]]]],
       [:assoc_new,
        [:@label, "status:", [1, 59]],
        [:binary,
         [:var_ref, [:@ivar, "@error_code", [1, 67]]],
         :"&&",
         [:return0]]]]]],
    false]]]]

Ripper 的输出并不是最容易阅读的，但如果我们密切注意这些函数调用的缩进，我们可以看到andcase 正在调用render(... '..._requirements') and return，而&&case 正在调用render(... '..._requirements' && return)。这两个表达式将有非常不同的行为。

于 2016-02-06T07:14:50.730 回答
2

就像您的帖子下的评论一样，您确实不需要在return这里。

但是，如果您仍然想使用return它并使其遵循 RuboCop 样式，请尝试使用括号包裹渲染参数。

render('errors/status_code', layout: 'errors/status_code', status: @error_code) && return

于 2016-02-06T07:09:58.353 回答