By default, the datetime field from the database is being converted and stripping off the milliseconds:
some_datetime => "2009-11-11T02:19:36Z"
attribute_before_type_cast('some_datetime') => "2009-11-11 02:19:36.145"
If I try to overrride the accessor for this attribute like;
def some_datetime
attribute_before_type_cast('some_datetime')
end
when I try "to_xml" for that model, I get the following error:
NoMethodError (undefined method
`xmlschema' for "2009-11-11
02:19:36.145":String):
I have tried to parse the String to a Time object but can't get one to include the milliseconds;
def some_datetime
Time.parse(attribute_before_type_cast('some_datetime').sub(/\s/,"T").sub(/$/,"Z"))
end
Can anyone help get get a datetime with milliseconds rendered by to_xml?
As it turns out, I can exclude the original datetime field, and add a custom method which in turn renders the datetime as a string to the to_xml. This feels hackish, but it's working.. Is there another way to get milliseconds directly in the original datetime field?
In each model, I exclude "except" the field names that have datetimes that I want changed, and I include "methods" with the same name returning the attribute before it is typecasted.
def to_xml(options = {})
options[:methods] = [:some_datetime]
options[:except] = [:some_datetime]
super
end
def some_datetime
attribute_before_type_cast('some_datetime')
end
Rendering to_xml is working great with models included and any other options I pass in.
I have started to learn Ruby and was impressed by Mats "Principle of Least Surprise".
But the Date and Time implementation in Ruby ( and Rails ) is full of surprises:
Starting with a plain irb:
require 'time'
=> true
dt = Time.now
=> 2010-05-31 17:18:39 +0100
Time.parse(dt.to_s) == dt
=> false !?!?!?!?
dt.to_s(:db)
ArgumentError: wrong number of arguments(1 for 0)
from (irb):5:in to_s'
from (irb):5
from C:/Ruby19/bin/irb:12:in'
ok lets take some Rails:
sqlserver_test/development?: dt2 = Time.zone.now
=> Mon, 31 May 2010 17:24:54 CEST +02:00
sqlserver_test/development: dt2.class
=> ActiveSupport::TimeWithZone
sqlserver_test/development: Time.zone.parse(dt2.to_s) == dt2
=> false
sqlserver_test/development: dt2.to_s(:db)
=> "2010-05-31 15:24:54"
sqlserver_test/development: dt2.to_s(:iso8601)
=> "2010-05-31 17:24:54 +0200"
sqlserver_test/development: dt2.to_s(:iso8601) == dt2.iso8601
=> false
( all running on Ruby 1.9.1 with Rails 2.3.5 on Windows Xp )
Currently I only find several "hacks" regarding DateTime fields and databases
but no clean solution WITHOUT surprises ...
Related
I need to be able to receive a user-input timestamp, with an optional time zone component, validate that is it a valid ISO 8601 time representation, and parse it according to the user's configured time zone.
I'm using Rails 4.2.6 on Ruby 2.3. I had hoped that Time.zone (ActiveSupport::TimeZone) would have an equivalent implementation to Time::iso8601 so that I could rescue ArgumentError exceptions to determine if the user input was a valid ISO 8601 time representation. Then I could do something like:
user_time_zone = 'America/Los_Angeles' # Would actually be from user's stored settings
params = {when: '2016-04-01T01:01:01'} # Would actually be from user input
# Would actually use Time::use_zone in around_action filter
Time.use_zone(user_time_zone) do
timestamp = Time.zone.iso8601 params[:when]
end
But, alas, no such method exists. And I can't find an equivalent one.
I can't use Time.zone.parse, because it treats ambiguous dates as valid (e.g. Time.zone.parse '04/11/16' # => Tue, 16 Nov 0004 00:00:00 LMT -07:52).
The best alternative I've been able to come up with so far is:
Time.use_zone(user_time_zone) do
old_tz = ENV['TZ']
ENV['TZ'] = Time.zone.name
timestamp = Time.iso8601 params[:when] # => 2016-04-01 01:01:01 -0700
ENV['TZ'] = old_tz
end
But this is ugly, messing around with an environment variable this way doesn't feel proper, and it and certainly isn't Rails-like. How can I validate and parse the time according to the user's time zone in a Rails way?
I suggest that you simply split the assignment into two steps: validate the ISO8601 format first and if valid, parse it:
user_time_zone = 'America/Los_Angeles'
params = { when: '2016-04-01T01:01:01' }
begin
Time.iso8601(params[:when]) # raises ArgumentError if format invalid
rescue ArgumentError => e
puts "invalid time format"
return
end
Time.use_zone(user_time_zone) do
timestamp = Time.zone.parse(params[:when])
end
I think you can still use an around_action for your use case. That's what I use and it works well for me.
In my ApplicationController I have:
class ApplicationController < ActionController::Base
around_action :set_time_zone
def set_time_zone
old_time_zone = Time.zone
Time.zone = user_time_zone
yield
ensure
Time.zone = old_time_zone
end
end
Any calls to Time will use the user's time zone within the scope of the request.
I am using Mongoid and Chronic gem. Chronic produces a Time object, and Mongoid Date object produces a DateTime object. So in Mongoid, when i want to get today, I do something like this:
Lead.last.send('lead date') # => {DateTime}2015-03-30T00:00:00-04:00
In Chronic, when I parse today, I get this:
Chronic.parse('today') # => {Time}2015-03-30 23:00:00 -0400
And I compare the two with ==, it produces false, even though they are the same date. I need the following query to give a result, when 'lead date' refers to today:
Lead.where("lead date" => Chronic.parse('today'))
What options do I have?
Does this code accurately replicate your issue?
require 'chronic'
require 'date'
text = "2015-03-30T00:00:00-04:00"
datetime = DateTime.parse(text)
time = Chronic.parse(text)
datetime == time
#=> false
Use the DateTime #to_time method, or the Time #to_datetime method:
datetime.to_time == time
#=> true
datetime == time.to_datetime
#=> true
How do I get DateTime to parse a custom date format(i.e. 'x-%Y')?
I've set the format within an initializer with (as per the RoR API):
Time::DATE_FORMATS[:x_year] = 'x-%Y'
Date::DATE_FORMATS[:x_year] = 'x-%Y'
and when I call:
DateTime.strptime('x-2011', 'x-%Y')
The correct result is returned, but
DateTime.parse('x-2011')
Throws an
ArgumentError: invalid date
never heard of such a possibility. However, you could still do something like:
class DateTime
class << self
alias orig_parse parse
end
def self.parse(string, format = nil)
return DateTime.orig_parse(string) unless format
DateTime.strptime(string, Date::DATE_FORMATS[format])
end
end
in your example it might look like that:
Date::DATE_FORMATS.merge!({:xform => "x-%Y"})
DateTime.parse('x-2011', :xform) #=> Sat, 01 Jan 2011 00:00:00 +0000
You could get rid of 'format' attribute and iterate && validate/rescue through DATE_FORMATS instead
I'm working on a rails project for an Australian website. As a result, they want to be able to enter date formats in the more european-standard of 'dd/mm/yyyy' rather than the US-centric 'mm/dd/yyyy'. I have an ActiveRecord model with a Date field. I'm using jQuery's datepicker to provide the date select on a text field, and have it setting the date to a proper format. But, when I try to save the record, it gets the date wrong. Even when I've set the custom date formats in an intializer according to the i18n guide.
>> b = BlogPost.new
>> b.posted_on = '20/07/2010'
=> "20/07/2010"
>> b.posted_on
=> nil
>> b.posted_on = '07/20/2010'
=> Tue, 20 Jul 2010
It seems that Rails is just using Date.parse to convert the string into a Date object. Is there any way to fix this for the whole project? I don't want to have to write custom code for each model.
class Date
class << self
def _parse_with_us_format(date, *args)
if date =~ %r{^(\d+)/(\d+)/(\d+)$}
_parse_without_us_format("#{$3.length == 2 ? "20#{$3}" : $3}-#{$1}-#{$2}", *args)
else
_parse_without_us_format(date, *args)
end
end
alias_method_chain :_parse, :us_format
end
end
Try to change the default date format (in config/environment.rb)
ActiveSupport::CoreExtensions::Time::Conversions::DATE_FORMATS.
merge!(default => '%d/%m/%Y %H:%M')
Find out more here http://blog.nominet.org.uk/tech/2007/06/14/date-and-time-formating-issues-in-ruby-on-rails/
I am implementing a full text search API for my rails apps, and so far have been having great success with Thinking Sphinx.
I now want to implement a date range search, and keep getting the "bad value for range" error.
Here is a snippet of the controller code, and i'm a bit stuck on what to do next.
#search_options = { :page => params[:page], :per_page => params[:per_page]||50 }
unless params[:since].blank?
# make sure date is in specified format - YYYY-MM-DD
d = nil
begin
d = DateTime.strptime(params[:since], '%Y-%m-%d')
rescue
raise ArgumentError, "Value for since parameter is not a valid date - please use format YYYY-MM-DD"
end
#search_options.merge!(:with => {:post_date => d..Time.now.utc})
end
logger.info #search_options
#posts = Post.search(params[:q], #search_options)
When I have a look at the log, I am seeing this bit which seems to imply the date hasn't been converted into the same time format as the Time.now.utc.
withpost_date2010-05-25T00:00:00+00:00..Tue Jun 01 17:45:13 UTC 2010
Any ideas? Basically I am trying to have the API request pass in a "since" date to see all posts after a certain date. I am specifying that the date should be in the YYYY-MM-DD format.
Thanks for your help.
Chris
EDIT: I just changed the date parameters merge statement to this
#search_options.merge!(:with => {:post_date => d.to_date..DateTime.now})
and now I get this error
undefined method `to_i' for Tue, 25 May 2010:Date
So obviously there is something still not setup right...
lets say d = "2010-12-10"
:post_date => (d.to_time.to_i..Time.now.to_i) would have gotten you there. I just did this in my project and it works great
I finally solved this, but it takes a slightly different approach but it works fine.
I was trying to put the date-range search inside a sphinx_scope (in the model) or as a :condition or :with (in the controller). This did not work, so instead I had to implement it inside the define_index in the model.
So what I did was put a check in the define_index to see if a record fell within a date range, the date range being defined by some SQL code, as shown below. In this case, I wanted to see if "start_date" fell within a date between now and 30 days ago, and an "end_date" fell within today and 30 days from now.
If the dates fell within the ranges, the code below causes the :live to be 0 or 1, depending on whether it falls outside or inside the date ranges (respectively):
define index do
# fields:
...
# attributes:
has "CASE WHEN start_date > DATE_ADD(NOW(), INTERVAL -30 DAY) AND end_date < DATE_ADD(NOW(), INTERVAL 30 DAY) THEN 1 ELSE 0 END", :type => :integer, :as => :live
...
# delta:
...
end
Then in your controller, all you have to do is check if :live => 1 to obtain all records that have start_dates and end_dates within the date ranges.
I used a sphinx_scope like this:
sphinx_scope(:live) {
{ :with => { :live => 1 } }
}
and then in my controller:
#models = Model.live.search(...)
To make sure it works well, you of course need to implement frequent reindexing to make sure the index is up to date, i.e. the correct records are :live => 1 or 0!
Anyway, this is probably a bit late for you now, but I implemented it and it works like a charm!!!
Wouldn't it work if you replaced
d = DateTime.strptime(params[:since], '%Y-%m-%d')
by
Time.parse(params[:since]).strftime("%Y-%m-%d")
(It seems the first one doesn't return a date in the expected format)