如何使用Ruby 1.9在Rails中使用美式日期？ [英] How can I use US-style dates in Rails using Ruby 1.9?

问题描述

我在美国，我们通常将日期格式设置为月/日/年。我试图确保我的Rails应用程序，使用Ruby 1.9，在所有地方都采用这种格式，并且在Ruby 1.8下工作。

I'm in the U.S., and we usually format dates as "month/day/year". I'm trying to make sure that my Rails app, using Ruby 1.9, assumes this format everywhere, and works the way it did under Ruby 1.8.

我知道很多的人有这个问题，所以我想在这里创建一个明确的指南。

I know that lots of people have this issue, so I'd like to create a definitive guide here.

具体来说：

1. '04 / 01/2011'是2011年4月1日，而不是2011年1月4日。


2. '4/1/2011'也是2011年4月1日 - 不需要前导零。

我该怎么做？

这是我到目前为止。

我在 application.rb 中有这一行：

    # Format our dates like "12/25/2011'
    Date::DATE_FORMATS[:default] = '%m/%d/%Y'

确保如果我执行以下操作：

This ensures that if I do the following:

d = Date.new(2011,4,1)
d.to_s

...我得到04 / 01/20 11，而不是2011-04-01。

... I get "04/01/2011", not "2011-04-01".

ActiveSupport的 String＃to_date 方法目前看起来像这样（资源）：

ActiveSupport's String#to_date method currently looks like this (source):

 def to_date
    return nil if self.blank?
    ::Date.new(*::Date._parse(self, false).values_at(:year, :mon, :mday))
  end

（如果你不遵循这一点，第二行创建一个新的日期，以年，月，日顺序。它通过使用 Date._parse 获得年，月和日值，它解析一个字符串，并以某种方式决定这些值是什么，然后返回一个哈希值。 .values_at 按照 Date.new 要求他们的顺序拉出该哈希值。）

(In case you don't follow that, the second line creates a new date, passing in year, month and day, in that order. The way it gets the year, month and day values is by using Date._parse, which parses a string and somehow decides what those values are, then returns a hash. .values_at pulls the values out of that hash in the order Date.new wants them.)

由于我知道我通常会传递像04/01/2011或4/1/2011这样的字符串，我可以通过monkeypatching来修复它：

Since I know that I will normally pass in strings like "04/01/2011" or "4/1/2011", I can fix this by monkeypatching it like this:

class String

  # Keep a pointer to ActiveSupport's String#to_date
  alias_method :old_to_date, :to_date

  # Redefine it as follows
  def to_date
    return nil if self.blank?
    begin
      # Start by assuming the values are in this order, separated by /
      month, day, year = self.split('/').map(&:to_i)
      ::Date.new(year, month, day)
    rescue
      # If this fails - like for "April 4, 2011" - fall back to original behavior
      begin
      old_to_date
      rescue NoMethodError => e
        # Stupid, unhelpful error from the bowels of Ruby date-parsing code
        if e.message == "undefined method `<' for nil:NilClass"
          raise InvalidDateError.new("#{self} is not a valid date")
        else
          raise e
        end
      end
    end
  end
end

class InvalidDateError < StandardError; end;

此解决方案使我的测试通过，但它是疯狂的吗？我只是在某个地方缺少一个配置选项，还是有其他更容易的解决方案？

This solution makes my tests pass, but is it crazy? Am I just missing a configuration option somewhere, or is there some other, easier solution?

有没有其他的日期解析案例我没有覆盖？ >

Are there any other date-parsing cases I'm not covering?

推荐答案

宝石：ruby-american_date

题。我现在正在使用它，并且很高兴。

Gem: ruby-american_date

This gem was created since I asked this question. I'm now using it and have been pleased.

https：// github.com/jeremyevans/ruby-american_date

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