ruby-on-rails - Rails错误处理/记录: Simplified backtrace

Question

我正在为Rails应用程序记录系统的错误，以发现所有隐藏的错误。

到目前为止，我已经在ApplicationController上使用rescue_from实现了这一点(请注意，我处于实验阶段，因此仅将结果输出到控制台)

 rescue_from Exception, with: :log_exception

 private
 def log_exception exception
 puts("Exception at #{Time.now.strftime('%d %b %Y, %H:%M')}")
 puts exception
 puts exception.backtrace.join "\n"
 raise exception
 end

我遇到的问题是exception.backtrace。它输出一堆看起来像这样的无用的深层跟踪

/Users/marcoprins/.rvm/gems/ruby-2.0.0-p451/gems/activemodel-3.2.13/lib/active_model/attribute_methods.rb:407:in `method_missing'
/Users/marcoprins/.rvm/gems/ruby-2.0.0-p451/gems/activerecord-3.2.13/lib/active_record/attribute_methods.rb:149:in `method_missing'
/Users/marcoprins/Desktop/Project/tillyoudrop/app/models/order.rb:105:in `cancel!'
/Users/marcoprins/Desktop/Project/tillyoudrop/app/controllers/admin/orders_controller.rb:97:in `cancel'
/Users/marcoprins/.rvm/gems/ruby-2.0.0-p451/gems/actionpack-3.2.13/lib/action_controller/metal/implicit_render.rb:4:in `send_action'
/Users/marcoprins/.rvm/gems/ruby-2.0.0-p451/gems/actionpack-3.2.13/lib/abstract_controller/base.rb:167:in `process_action'
/Users/marcoprins/.rvm/gems/ruby-2.0.0-p451/gems/actionpack-3.2.13/lib/action_controller/metal/rendering.rb:10:in `process_action'
/Users/marcoprins/.rvm/gems/ruby-2.0.0-p451/gems/actionpack-3.2.13/lib/abstract_controller/callbacks.rb:18:in `block in process_action'
/Users/marcoprins/.rvm/gems/ruby-2.0.0-p451/gems/activesupport-3.2.13/lib/active_support/callbacks.rb:436:in `_run__4209411771832668003__process_action__2626133284113442857__callbacks'
/Users/marcoprins/.rvm/gems/ruby-2.0.0-p451/gems/activesupport-3.2.13/lib/active_support/callbacks.rb:405:in `__run_callback'
/Users/marcoprins/.rvm/gems/ruby-2.0.0-p451/gems/activesupport-3.2.13/lib/active_support/callbacks.rb:385:in `_run_process_action_callbacks'
/Users/marcoprins/.rvm/gems/ruby-2.0.0-p451/gems/activesupport-3.2.13/lib/active_support/callbacks.rb:81:in `run_callbacks'

它持续了好几英里。

我希望我的错误日志文件看起来干净且可读，所以我所要的只是本示例的第三行和第四行，或者更确切地说，Rails在错误页面中输出的确切行，(参见图片)告诉我的部分确切地是，在我的代码中是错误的来源。

如何访问这些行？ exception对象上是否包含一个属性？

Answer 1

通过模式与您要提取或忽略的文件/目录匹配来拒绝或选择某些行。例如，如果要忽略/gems/中的步骤，则:

exception.backtrace.reject{|l| l =~ %r|\A[^:]*/gems/|}

如果只需要 /app/目录中的步骤，则:

exception.backtrace.select{|l| l =~ %r|\A[^:]*/app/|}

实际上，您应该使用 backtrace_locations而不是 backtrace，它无需使用正则表达式即可直接访问路径，但是暂时 backtrace_locations充满了错误，并且不实用。