timezone_field

This is a simple library for letting Rails apps store standard TZinfo identifiers in the database, while still using friendly Rails zone names in application logic. It also handles validation and inflating/deflating timezone strings into ActiveSupport::TimeZone objects automatically.

Usage

class Model < ActiveRecord::Base
  include TimezoneField
  has_timezone_field :my_field
end

# assigning a TZInfo identifier
model.my_field = "America/Los_Angeles"
# still looks like Rails!
model.my_field.name
=> "Pacific Time (US & Canada)"

# assigning a Rails identifier
model.my_field = "Pacific Time (US & Canada)"
model.my_field.name
=> "Pacific Time (US & Canada)"
# Gets stored as a TZinfo identifier!
model.read_attribute(:my_field)
=> "America/Los_Angeles"

# assigning a bogus identifier
model.my_field = "HAMMER TIME"
model.valid?
=> false
model.errors
=> {:timezone=>["Unrecognized timezone"]}
=> model.my_field == Time.zone
=> true

# handling of nil values - returns Time.zone
model.my_field = nil
model.valid?
=> true
=> model.my_field == Time.zone
=> true

Why?

ActiveSupport::TimeZone supports two formats for timezone strings - Rails has a set of human-friendly zone strings, which are aliases for the standard TZInfo identifiers used by the rest of the world. This library attempts to hide the mapping under the covers. Your data will be stored in a standard format, while still being friendly with Rails.

Handling unrecognized zones

When encountering blank or unrecognized zones, this library returns the current value of Time.zone, rather than nil. I found myself writing current_user.timezone || Time.zone a lot, and decided a nil timezone doesn't really make sense - you're probably using this field to store user timezone settings, and if they didn't set one, you probably want to default. A caveat to be aware of if you're writing migrations or something.