Rails 时区也不会覆盖答案

【问题标题】：Rails time zone not overrides as wellRails 时区也不会覆盖
【发布时间】：2011-12-11 23:33:54
【问题描述】：

我在我的 Rails 项目中遇到了 UTC 的嘈杂问题。

class ApplicationController < ActionController::Base
   before_filter :set_timezone

   def set_timezone
     Time.zone = current_user.time_zone if current_user
   end

酷。我覆盖了时区。现在，服务器的时区是+3。用户的时区是+5。我希望对 Time 的任何请求都应该获取用户的时区，但此代码返回的不是预期值：

render :text => Time.zone.to_s + "<br/>" +
                Time.now.to_s + "<br/>" +
                Time.now.in_time_zone.to_s

结果：

(GMT+05:00) Tashkent
Thu Oct 20 19:41:11 +0300 2011
2011-10-20 21:41:11 +0500

+0300 偏移从哪里来？？

【问题讨论】：

标签： ruby-on-rails timezone utc

【解决方案1】：

要在当前设置的时区中获取当前时间，您可以使用

Time.zone.now

您的服务器时区是 +3 并且

Time.now.to_s   is returning this

【讨论】：

【解决方案2】：

萨哈！抱歉，我没有 15 点声望让你升级））。无论如何感谢您的帮助。我写了一个 TimeUtil 助手，用于时间校正。这是我目前的伪代码：

class RacesController < ApplicationController
  def create
    @race = Race.new(params[:race])
    @race.correct_time_before_save   #can be before_save
    @race.save
  end

class Race < ActiveRecord::Base
  def correct_time_before_save
    date = self.attributes["race_date"]
    time = self.attributes["race_time"]
    datetime = Time.local(date.year, date.month, date.day, time.hour, time.min, time.sec)
    datetime_corrected = TimeUtil::override_offset(datetime)
    self.race_date = datetime_corrected.to_date
    self.race_time = datetime_corrected.to_time
  end

# TimeUtil is uses for time correction. It should be very clear, please read description before using.
# It's for time correction, when server's and user's time zones are different.
# Example: User lives in Madrid where UTC +1 hour, Server had deployed in New York, UTC -5 hours.
# When user say: I want this race to be started in 10:00.
# Server received this request, and say: Okay man, I can do it!
# User expects to race that should be started in 10:00 (UTC +1hour) = 09:00 UTC+0
# Server will start the race in 10:00 (UTC -5 hour) = 15:00 UTC+0
#
# This module brings the workaround. All that you need is to make a preprocess for all incoming Time data from users.
# Check the methods descriptions for specific info.
#
# The Time formula is:
#                       UTC + offset = local_time
#                    or
#                       UTC = local_time - offset
#

module TimeUtil

# It returns the UTC+0 DateTime object, that computed from incoming parameter  "datetime_arg".
# The offset data in "datetime_arg" is ignored - it replaces with Time.zone offset.
# Time.zone offset initialized in ApplicationController::set_timezone before-filter method.
#
def self.override_offset datetime_arg      
  Time.zone.parse(datetime_arg.strftime("%D %T")).utc
end

ActiveRecord getter 也适应用户的时区。时间以“utc+0”格式存储在数据库（mysql）中，我们想以当前用户的时区格式获取这个时间：

class Race < ActiveRecord::Base
  def race_date
    date = self.attributes["race_date"]
    time = self.attributes["race_time"]
    datetime = Time.utc(date.year, date.month, date.day, time.hour, time.min, time.sec).in_time_zone
    datetime.to_date
  end

  def race_time
    date = self.attributes["race_date"]
    time = self.attributes["race_time"]
    datetime = Time.utc(date.year, date.month, date.day, time.hour, time.min, time.sec).in_time_zone
    datetime.to_time
  end

【讨论】：