Re: [Rails] Converting a Time to a String and Back in Rails 4.0.0

[Tamara Temple]

On Aug 15, 2013, at 7:15 PM, Phil <ph...@edgedesign.us> wrote:
> I'm porting an old rails app to Rails 4 and got stumped tonight on time conversions.
>
> This worked:
>
> Loading development environment (Rails 2.3.18)
> > > Time.now.to_s
> => "08/14/2013 07:09PM"
> > > Time.now.to_s.to_time
> => Wed Aug 14 19:09:00 UTC 2013
>
> Now it doesn't on Rails 4.0:
>
> Loading development environment (Rails 4.0.0)
> irb(main):001:0> Time.now
> => 2013-08-15 00:19:48 -0500
> irb(main):002:0> Time.now.to_s
> => "08/15/2013 12:19AM"
> irb(main):003:0> Time.now.to_s.to_time
> ArgumentError: argument out of range
> from /usr/local/lib/ruby/gems/2.0.0/gems/activesupport-4.0.0/lib/active_support/core_ext/string/conversions.rb:23:in `initialize'
> from /usr/local/lib/ruby/gems/2.0.0/gems/activesupport-4.0.0/lib/active_support/core_ext/string/conversions.rb:23:in `new'
>
> If I remove this from my initializer:
>
> Time::DATE_FORMATS.merge!(:default => '%m/%d/%Y %I:%M%p')
>
> It works again in 4.0, but the output format is wrong. I don't want my users reading that time format:
>
> Loading development environment (Rails 4.0.0)
> irb(main):001:0> Time.now.to_s
> => "2013-08-15 00:32:07 -0500"
> irb(main):002:0> Time.now.to_s.to_time
> => 2013-08-15 00:32:15 -0500
>
> If it were a simple single string I was parsing, I could do a custom one off parse and be done with it, but this is site wide. Passing entire hashes to models is causing this error to manifest its self.
>
> Any ideas to get Rails 4.0 to not just produce a custom Time string but parse the same way as well? Seems like it should be simple, but perhaps it's just getting late here. ;')
>
> Thanks!

This isn't a Rails problem, it's something that happens in Ruby. I think it's a bug:

$ irb -r date
irb(main):001:0> format = "%m/%d/%Y"
=> "%m/%d/%Y"
irb(main):002:0> Date.parse(Date.today.strftime(format),format)
ArgumentError: invalid date
from (irb):2:in `parse'
from (irb):2
from /Users/tamara/.rubies/ruby-2.0.0-p427/bin/irb:12:in `<main>'
irb(main):003:0> Date.today.strftime(format)
=> "08/18/2013"
irb(main):004:0> Date.parse(Date.today.to_s)
=> #<Date: 2013-08-18 ((2456523j,0s,0n),+0s,2299161j)>


$ ruby -v
ruby 2.0.0p247 (2013-06-27 revision 41674) [x86_64-darwin12.4.0]


I don't have anything older to check this on, however, reading the system documentation for strptime(), it seems to state that formats should be compatible with strftime().

A quick test in C[1] shows that the format from strftime to strptime is compatible. So sounds like a ruby bug…

—
[1] https://gist.github.com/tamouse/6263292

[Hassan Schroeder]

On Thu, Aug 15, 2013 at 5:15 PM, Phil <ph...@edgedesign.us> wrote:

I'm porting an old rails app to Rails 4 and got stumped tonight on time conversions.

This worked:

Loading development environment (Rails 2.3.18)

> > Time.now.to_s
=> "08/14/2013 07:09PM"

Now it doesn't on Rails 4.0:

Loading development environment (Rails 4.0.0)

irb(main):002:0> Time.now.to_s
=> "08/15/2013 12:19AM"

1.9.3 (main):0 > Date.parse("08/20/2013").to_s

ArgumentError: invalid date

from (pry):22:in `parse'

1.9.3 (main):0 > Date.parse("20/08/2013").to_s

=> "2013-08-20"

1.9.3 (main):0 >

In the source for e.g. ruby-1.9.3-p448 see ./doc/NEWS-1.9.1:

o Time.parse and Date.parse interprets slashed numerical dates·

     as "dd/mm/yyyy".      

 

HTH!
--
Hassan Schroeder ------------------------ hassan.s...@gmail.com
http://about.me/hassanschroeder
twitter: @hassan

[Philip Edelbrock]

Thanks! Yes, I did update to Ruby 2.0.0p247, but I also updated to Rails-4 and, well, entirely new hardware and OS as well, so I'm not sure where the bug is exactly.

I worked around it for now:

params[:form][:time_field] = Time.strptime(params[:form][:time_field],"%m/%d/%Y %I:%M%p")
@myobj = MyObj.new(params[:form].permit!)


Phil

[Philip Edelbrock]

On Aug 20, 2013, at 7:57 AM, Hassan Schroeder <hassan.s...@gmail.com> wrote:

>
> In the source for e.g. ruby-1.9.3-p448 see ./doc/NEWS-1.9.1:
>
> o Time.parse and Date.parse interprets slashed numerical dates·
> as "dd/mm/yyyy".
>

Well, back to basics, my question is simple:

How do I tell Rails to use a custom date/time format without it blowing up?

I put this in an initializer:

Date::DATE_FORMATS.merge!(:default => '%m/%d/%Y')

Time::DATE_FORMATS.merge!(:default => '%m/%d/%Y %I:%M%p')

This is how I do that in Rails 2.3/Ruby 1.8.7, btw:

ActiveSupport::CoreExtensions::Date::Conversions::DATE_FORMATS.merge!(:default => '%m/%d/%Y')
ActiveSupport::CoreExtensions::Time::Conversions::DATE_FORMATS.merge!(:default => '%m/%d/%Y %I:%M%p')

That causes Rails 4.0/Ruby 2.0 to eat its self when dealing with forms that have dates/times. I'm not calling Date or Time directly in this case. I'm just letting Rails populate forms and then parse the params on submission to update a model. It is outputting the correct format, but it can't seem to parse what it is outputting. This wasn't a problem with Rails 2.3/Ruby 1.8.7.

A simple way to manifest the problem is to do "Time.now.to_s.to_time" or "Date.today.to_s.to_date". This works on Rails 2.3/Ruby 1.8.7, but does not on Rails 4.0/Ruby 2.0 with the above initializers.

It is hard to believe that they removed such basic functionality? Tamara suggests this might be a Ruby bug(?).

Thanks!


Phil

[Hassan Schroeder]

On Tue, Aug 20, 2013 at 1:06 PM, Philip Edelbrock <ph...@edgedesign.us> wrote:

> o Time.parse and Date.parse interprets slashed numerical dates·
>      as "dd/mm/yyyy".
>

Well, back to basics, my question is simple:

How do I tell Rails to use a custom date/time format without it blowing up?

I put this in an initializer:

Date::DATE_FORMATS.merge!(:default => '%m/%d/%Y')

See my previous comment; that format IS NOT VALID in Ruby 1.9.x and 

above. Your issue has nothing to do with Rails.

 

A simple way to manifest the problem is to do "Time.now.to_s.to_time" or "Date.today.to_s.to_date".  This works on Rails 2.3/Ruby 1.8.7, but does not on Rails 4.0/Ruby 2.0 with the above initializers.

It works fine with VALID formats. Change your initializer to '%d/%m/%Y'

and try `Date.today.to_s.to_date`  -- no problem.

It is hard to believe that they removed such basic functionality?  Tamara suggests this might be a Ruby bug(?).

No. It is documented behavior of Ruby.

 

[Tamara Temple]

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The documentation, however, points to the libc functions, strftime(3) and strptime(3), which state quite plainly that these formats are reflexive. Hardly seems sporting, does it? Without including a format field, it's probably quite reasonable to assume the parse methods will interpret in that dd/mm/yyyy order, BUT, *with* a format field?? They should not ignore the format field in that case. *That* is the bug.

[Colin Law]

On 20 August 2013 21:06, Philip Edelbrock <ph...@edgedesign.us> wrote:
>
> On Aug 20, 2013, at 7:57 AM, Hassan Schroeder <hassan.s...@gmail.com> wrote:
>
>>
>> In the source for e.g. ruby-1.9.3-p448 see ./doc/NEWS-1.9.1:
>>
>> o Time.parse and Date.parse interprets slashed numerical dates·
>> as "dd/mm/yyyy".
>>
>
> Well, back to basics, my question is simple:
>
> How do I tell Rails to use a custom date/time format without it blowing up?

The american_date gem may help [1]

Colin

[1] https://github.com/jeremyevans/ruby-american_date

[Phil]

On Wednesday, August 21, 2013 7:18:35 AM UTC-7, Hassan Schroeder wrote:

On Tue, Aug 20, 2013 at 1:06 PM, Philip Edelbrock <ph...@edgedesign.us> wrote:

> o Time.parse and Date.parse interprets slashed numerical dates·
>      as "dd/mm/yyyy".
>

Well, back to basics, my question is simple:

How do I tell Rails to use a custom date/time format without it blowing up?

I put this in an initializer:

Date::DATE_FORMATS.merge!(:default => '%m/%d/%Y')

See my previous comment; that format IS NOT VALID in Ruby 1.9.x and 

above. Your issue has nothing to do with Rails.

 

A simple way to manifest the problem is to do "Time.now.to_s.to_time" or "Date.today.to_s.to_date".  This works on Rails 2.3/Ruby 1.8.7, but does not on Rails 4.0/Ruby 2.0 with the above initializers.

It works fine with VALID formats. Change your initializer to '%d/%m/%Y'

and try `Date.today.to_s.to_date`  -- no problem.

It is hard to believe that they removed such basic functionality?  Tamara suggests this might be a Ruby bug(?).

No. It is documented behavior of Ruby.

 

Don't get me wrong, I appreciate your help!

It just seems that this was functionality that seemed to have been broken.  It's not a 'valid' vs. invalid argument (where I live, m/d/y is valid and d/m/y is not!)  I should be able to define 1/13/2 as being Feb 1st, 2013 if I want to be crazy about it.  String parsing isn't hard, it just seems to be eluding me as how to hint Rails 4/Ruby 2 on how to do it the way I want when it worked in the past.

As Tamara suggests, it appears the format string is being dropped by the time it makes it to the parsing function(?).  d/m/y is fine as a default, but saying to change my initializer to match the already default is like removing it all together and doesn't solve my localization problem.

Phil

[Hassan Schroeder]

On Wed, Aug 21, 2013 at 8:55 PM, Phil <ph...@edgedesign.us> wrote:

It's not a 'valid' vs. invalid argument

Of course it is. What you consider valid or not is irrelevant, it's defined in the language.

You happened to be lucky in picking a format (%m/%d/%Y) that worked in Ruby 1.8.7; 

the opposite day/month placement %d/%m/%Y doesn't:

1.8.7 :008 > Date.parse(Date.today.strftime('%m/%d/%Y')).to_s

 => "2013-08-22"

1.8.7 :009 > Date.parse(Date.today.strftime('%d/%m/%Y')).to_s

ArgumentError: invalid date

 

As Tamara suggests, it appears the format string is being dropped by the time it makes it to the parsing function(?). 

Date.parse doesn't take a format argument. The Rails String#to_date 

helper uses Date.parse. It "used to work" because you were lucky.

I can see an argument for replacing that with Date.strptime; why not

try it and see if anything breaks?  :-)

Add your use case to the tests and go for it.